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Pattern Change is Welcomed News After An Awesome Week of Weather.
Saturday, June 14

An approaching Cold Front and pre-frontal trof crossing the Mid-Atlantic States tonight is the harbinger of changes in this active and nasty weather pattern. Numerous severe storms lit up regional Radars this afternoon and evening. Here's a SVR approached Nelson County, VA (photo submitted by Andy):

A strong Upper Level Low (ULL) over Canada is moving toward the Great Lakes and will bring another Cold Front over the Lakes, Northeast and Mid-Atlantic early next week. Right now, it looks as though this boundary will cross the Mid-Atlantic late Monday or in the early hours of Tuesday. Timing isn't ideal for severe weather, but lines of storms should develop on Monday over the Ohio Valley and approach the Appalachians later in the evening. Heavy rain, wind and some hail could result from the stronger storms that develop...so keep an eye on our Severe WeatherCenter on Sunday and Monday for the latest information. Models hinting the highest risk for severe weather will move east to a line roughly from Syracuse, NY to Winchester, VA...although storms could fire up again over eastern PA and down to the Delmarva.

Behind this next front, we finally catch a break! In fact, after this week's record breaking heat, it will feel downright delightfully chilly. High temps this week soared to the upper 90's with some readings exceeding the century mark...70's will be the rule next week. Wednesday through Friday could see increasing chances for small pop-up storms in the afternoon but overall, a quiet week after Monday's threat passes.

TORNADOES: This has been a terrible week of weather: heat, floods and killer tornadoes. SPC reports indicate 115 tornadoes just this week. While the actual number will be lower, the toll has been numbing even to hardened storm chasers.

Wednesday's twister in Manhattan, Iowa has been evaluated and rated as an EF-4. Interestingly, this tornado was recorded live on a local TV station as it approached the community:

The other highly publicized tornado hit the Little Sioux Scout Ranch Boy Scout camp in Western Iowa, also on Wednesday. Many of you may know I am employed by a local council of the Boy Scouts of America and so the death of four Scouts was particularly distressing to me. All loss of life is tragedy, yet this event was especially painful. The camp was not open this week and Scouts and leaders were there for what is referred to as "pre-camp" week. On Tuesday, they conducted emergency training drills and by all accounts did exactly what was required when the EF-3 approached their camp. These young men and their leaders knew exactly what to do and then took control of the horrific situation until help arrived over 40 minutes later. There's no doubt this would have been worse were it not for heroic efforts by these Scouts and leaders before, during and after the tornado. They are the epitome of what is so very special about being a Scout.

NWS report and photos from the Boy Scout camp here.

Raw AP footage of the Boy Scout camp damage:

A small tornado was tracked at Miami Beach, Florida on Friday! Story and video here.

TROPICS: Not much brewing in the Atlantic, Caribbean and GOM right now. An interesting wave has rolled off Africa but is not expected to develop.

My son and I took a few days off earlier this week to make the pilgrimage to New York City and Yankee Stadium. This probably will be my final visit to the Stadium as the new ball park opens next season. We attended Monday's game (Yanks lost 3-2 to the Royals. Red Sox fans: contain yourselves!). It was ghastly hot: so hot, the team provided free cups of water. Of course, bottled water still sold for $4.50 apiece! After the game, I sat in the empting box seats and just looked over the ball park I have attended and loved for over 35 years. Very strange how attached we become to inanimate objects.

Happy Father's Day to all my fellow Dads!

Arthur Arrives On Hurricane Eve
Sunday, June 1

Invest 90L (remnant of Alma) became Tropical Storm Arthur and I believe this happened as the LLC was mostly over land. Unusual to say the least. High Pressure Ridging generally over the north and eastern Gulf will keep the weakening cyclone out of the Bay of Campeche. It would be interesting to see if this held together to reform over the Pacific. If so, that would make Alma and Arthur in the Pacific and Arthur in the Atlantic...three named storms and hurricane season has just begun!

As today is the "official" start of hurricane season, here's Dr. William (Bill) Gray's April forecast:

Forecast Parameter and
1950-2000 Climatology (in parentheses)

7 Dec 2007
Forecast for 2008

9 April
2008

Named Storms (NS) (9.6)

Named Storm Days (NSD) (49.1)

Hurricanes (H) (5.9)

Hurricane Days (HD) (24.5)

Intense Hurricanes (IH) (2.3)

Intense Hurricane Days (IHD) (5.0)

Accumulated Cyclone Engery (ACE) (96.1)

Net Tropical Cyclone Activity (NTC) (100%)

13
60

7

30

3

6

115

125

15
80

8

40

4

9

150

160

PROBABILITIES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL ON EACH OF THE FOLLOWING COASTAL AREAS:
1) Entire U.S. coastline - 69% (average for last century is 52%)
2) U.S. East Coast Including Peninsula Florida - 45% (average for last century is 31%)
3) Gulf Coast from the Florida Panhandle westward to Brownsville - 44% (average forecast last century is 30%)
4) Above-average major hurricane landfall risk in the Caribbean.

You can read the entire report from Philip Klotzbach and William Gray by clicking HERE.

A Cold Front crossed the region this evening and was the focal point of a pretty good line of storms. As usual, the mountains did their dirty work and I never hear a rumble of thunder, but did enjoy observing the sky bubble up. Here's a picture from north of Roanoke, VA:

click to enlarge.

Upon arriving back home in Lexington, VA, still without a drop of rain, I was treated to a waning rainbow from a nearby thunderstorm:

click to enlarge.

Hurricane Model Maps Now Available...Just In Time For
INVEST 90L...The Atlantic Basin's First System of 2008!

Plus...Historic Tornado Season Continues!
Friday, May 30

INVEST 90L: It's not "officially" hurricane season but we've already had our first named storm (Alma) in the Eastern Pacific and now have Invest 90L in the Atlantic Basin. In actuality, this is a Caribbean/Yucatan storm that has formed from energy of dissipating Alma. Maximum sustained winds are 30 kts with a developing LLC (low level center)...making this close to a Tropical Depression. However, proximity to the Yucatan Peninsula makes immediate development unlikely. We'll continue to monitor as the circulation could survive intact and emerge over the lower Bay of Campeche. I'm not bullish on this but certainly worth watching.

MODEL MAPS NOW AVAILABLE: Our world famous hurricane model maps are now up and running a couple day before the June 1st start of hurricane season. Bigger maps and a lower subscription price make our models affordable for anyone interested in tropical cyclones. And, our popular text messaging service returns in 2008: get new storm alerts delivered right to your cell phone! For model map information or to subscribe, please click HERE.

TORNADOES: There have been an astounding 132 tornado reports from last Sunday through tonight! Last Sunday produced 53 and Thursday's total exceeded 60. 2008 is on pace to break records for the total number of reported tornadoes...with several hitting or approaching major cities such as Atlanta and Norfolk. The severe threat moves east on Saturday...with Delmarva though NJ bearing the brunt of strong storms. Supercells are possible and therefore there is potential for tornadoes in the Mid-Atlantic. Straight-line winds and possibly hail are also threats, particularly late afternoon. Visit our Severe WeatherCenter for real time information.

Partly Personal: You may have noticed blogging has been scarce for the past several weeks. Part of the reason is this has been an amazingly tranquil Spring for most of the East. The main reason, however, has been my dealing with a rather serious family health issue. Time that would have been spent blogging here at Mid-Atlantic WX.com has been devoted to dealing with this ongoing period of uncertainty. We are encouraged by progress over the past several days and I hope for the best...as well as having some time to get back to the blog. As we've seen with Alma and Invest 90L, hurricane season appears eager to quickly get out of the gate. Thank you to those of you who have written to inquire on my decreased writing here at the blog. I hope to have an update on the tropics on Sunday morning.

Current Tornado Outbreak Death Toll: 23 At Least.
Sunday, May 11

I recall several years ago devoting Mother's Day to chasing in a Moderate Risk box over NOVA and MD. I never saw anything close to severe that day however Mother's Day 2008 has been far less kind. No fatalities in today's storm reports, however the past several days have produced a terrible outbreak. I dislike speculating on tornado strength but the video observed from the Picher, OK tornado appears massive and an EF-5 tornado is not ruled out by this author. Tornadoes and related fatalities certainly will well exceed last year's totals and we have half of May and all of June before "spring season" winds down.

As this is typed, I see a confirmed tornado has just touched down in Lewiston, NC, injuring two people.

Here's one of the most amazing tornado video captures I've ever seen! This is a looped clip from a surveillance camera in Leighton, AL actually showing the base of a tornado passing directly in front. Watch what happens to the vehicles. This tornado occurred last Thursday and was rated as an EF-2. The vehicles were not hit directly by this "small" tornado yet you can see they were tossed at least 40 feet! This video should remind everyone to never be in a vehicle as a tornado approaches!!!

A very potent line of storms is crossing the Mid-Atlantic States this afternoon as Low Pressure begins spinning up off the Delmarva Peninsula. An Upper Level Low (ULL) over the Ohio Valley will move East tonight and while the active weather of this afternoon's Tornado Watch area will wane, we could see storms fire up in the dry slot between these two Lows. Cloud cover and loss of what little daytime heating there has been today should keep advancing weather from becoming severe, but thunderstorms with some hail can't be ruled out tonight.

As the Upper Low passes, High Pressure builds in and the tight pressure gradient will produce gusty to strong winds late tonight and into Monday over the region.

Another batch of severe weather should develop Wednesday into Thursday for Texas, tornado alley and possibly the north-central Gulf States as the next Cold Front moves east. This frontal boundary arrives in the Mid-Atlantic on Thursday and should deliver more scattered strong storms to the area. We'll keep precipitation in the forecast into the weekend as a nasty trof of Low Pressure parks over the Eastern US...with several lobes of energy trigger drizzle/rain and some scattered storms. A very active pattern indeed.

MY WEDNESDAY MINI-CHASE:

Last Wednesday night I was in Waynesboro (Augusta), VA when a Tornado Watch was issued. A strong storm headed toward Nelson County and that's where my chasing began. Exiting at Afton Mountain, I was quickly able to observe numerous downed trees. Not far away, a car was on its side, apparently by straight line winds. Another cell was moving into Augusta County, so I headed that way and was able to get on decent picture before the rain began:

The Augusta County storm was severe but I couldn't get under it due to topography. A Tornado Warning was issued shortly after this storm raced Northeast over the Augusta/Rockingham County line. Again, the mountains cut short a promising night for me. The cell dumped nearly one inch hail at Charlottesville and was part of the system that later produced an EF-2 tornado in Stafford County, VA. My chaser buddies out west smirk when told we lose a rotating thunderstorm literally in minutes because of terrain and rural curvy roads. They think nothing of chasing a storm for 100 miles...here in the east, a quarter of that is good.

Several guys I chat with post on an excellent forum at StormTrack.org. If you'd like to read chaser reports and logs of this week's tornado outbreak click here.

Follow-Up on 4/28/08 Virginia Tornado Event..
Tuesday, April 29

Amid yesterday's hectic scene, I failed to mention a tornado in Halifax County, VA (South Boston, VA). NWS Blacksburg has published this report:

NATIONAL WEATHER SERVICE BLACKSBURG VA
215 PM EDT TUE APR 29 2008

...STORM DAMAGE IN HALIFAX COUNTY VIRGINIA CAUSED BY EF1 TORNADO...

A NATIONAL WEATHER SERVICE STORM SURVEY FOUND THAT STORM DAMAGE THAT OCCURRED
IN HALIFAX COUNTY VIRGINIA IN THE TOWN OF VIRGINIA MONDAY AFTERNOON WAS CAUSED
BY AN EF1 TORNADO.

WINDS IN THE STORM WERE ESTIMATED TO BE BETWEEN 86 AND 109 MPH.
THE STORM WAS ON THE GROUND FROM APPROXIMATELY 110 TO 115 PM. THE INITIAL DAMAGE
STARTED JUST SOUTH AND WEST OF THE INTERSECTIONS OF HIGHWAYS 96 AND 49.
THIS ON THE WESTERN EDGE OF THE TOWN OF VIRGINIA. THE TORNADO WAS ON THE
GROUND FOR APPROXIMATELY ONE MILE TRAVELING TO THE NORTHEAST. SPORADIC DAMAGE
OCCURRED FURTHER NORTHEAST ON GILLS MOUNTAIN ROAD FROM STRAIGHT LINE WINDS. AT THE
WIDEST POINT...THE TORNADO WAS 240 YARDS WIDE.

6 HOMES WERE DAMAGED...AND NUMEROUS LARGE TREES WERE DOWNED AND SNAPPED.

This tornadic storm was three hours ahead of the more serious weather in and near Suffolk, VA and is logical as the
severe weather traversed from southwest to northeast as the afternoon progressed.

First report on Colonial Heights tornado:

NATIONAL WEATHER SERVICE WAKEFIELD VA
405 PM EDT TUE APR 29 2008

... THE FOLLOWING IS A BRIEF SUMMARY OF TORNADO SURVEY RESULTS FOR
THE COLONIAL HEIGHTS, VA TORNADO ON APRIL 28, 2008...

SURVEY DAMAGE SCALE RESULT: EF1
ESTIMATED WINDSPEED: 86-110 MPH
TOTAL INJURIES: 21
TOTAL DEATHS: 0
PATH LENGTH: APPROX. 1/2 MILE
PATH WIDTH: APPROX. 75-80 YARDS

SUMMARY...

IN COLONIAL HEIGHTS...THE TORNADO APPEARED TO MOVE ALONG AN APPROXIMATELY ONE-HALF MILE,
75-80 YARD WIDTH PATH FROM SOUTHWEST TO NORTHEAST. AS INDICATED FROM THE DAMAGE,
THE TORNADO TOUCHED DOWN IN SPOTS BEGINNING NEAR THE END OF THE FOOTBALL FIELD
NEAR COLONIAL HEIGHTS MIDDLE SCHOOL, ACROSS INTERSTATE 95, INTO THE DIMMOCK SQUARE
SHOPPING CENTER. THE FIRST OF THE DAMAGE WAS TO A FOOTBALL FIELD CLUBHOUSE AS A PART OF
THE ROOF WAS BLOWN OFF. THE STORM THEN LIFTED ACROSS AN AREA OF HOMES AND TOUCHED DOWN
AGAIN JUST WEST OF THE INTERSTATE AND TEARING A PATH THROUGH THE ROOF OF THE MEDALLION
POOLS BUILDING. TWISTED METAL WAS STREWN ACROSS THE PARKING LOT WITH A FEW CARS DAMAGED
FROM THE FLYING DEBRIS. THE TORNADO LIFTED AGAIN ACROSS I-95 SCATTERING DEBRIS ACROSS
THE SOUTHGATE SQUARE PARKING LOT INCLUDING A HALF-TON AIR CONDITIONING UNIT BLOWN
APPROXIMATELY 300 YARDS AND DEPOSITED IN FRONT OF THE HELZBERG DIAMONDS BUSINESS
NEAR SOUTH PARK BOULEVARD.

THE MOST SIGNIFICANT DAMAGE OCCURRED WITH THE FINAL TOUCHDOWN IN THE DIMMOCK SQUARE
STRIP MALL. A STRING OF 4 STORES AROUND 75-80 YARDS IN WIDTH HAD CEILING TILES BLOWN OUT,
ROOF PEELED OFF AND WINDOWS BLOWN OUT. SEVERAL CARS WERE DAMAGED...AS SOME HAD WINDOWS
SHATTERED FROM FLYING DEBRIS. OTHER VEHICLES WERE FLIPPED AND TOSSED ABOUT IN
PILES. THE STORM APPEARED TO LIFT AGAIN BUT THERE WAS DAMAGE TO A BANK AND LIGHT POLES
BLOWN DOWN IN A CAR LOT APPROXIMATELY 50 TO 100 YARDS EAST OF DIMMOCK SQUARE.
CARS WERE ALSO DAMAGED HERE FROM THE FLYING DEBRIS.

Total number of yesterday's Virginia tornadoes is now at six.


I'm sharing the video below because it gives you a good sense of what chasing is like here in the East. We have far more 
obstructions than do our friends in Tornado Alley...as evidenced by the tornado  "popping out" from behind trees. I chuckled 
at hearing a horns blow as the Jesse V. Bass III (chaser/videographer) pulled out into traffic. Been there, done that!

Helicopter video and analysis from last evening over the Suffolk/Driver area.

Interesting to watch the video above and see how this tornado lifted and came down again. There are unconfirmed reports this occurred several times along a path that may reach 25 miles in length. The NWS is assessing an expansive damage path and will ultimately be able to determine the exact path, intensity and number of touchdowns for each tornado. Path of largest tornado:

View Larger Map

Loads more videos here: http://www.hamptonroads.tv/index.cfm?locvid=139644&tid=r700

Last night, I was reminded of a twister oddity I totally forgot. The violent La Plata, MD tornado also happened on April 28 (2002). I should have recalled the date as I remember chasing in the Shenandoah Valley and NOVA and that was the date a white tornado crossed I-81 here in the Valley. Pictures in our photo gallery (click to enlarge):

.

Video of the 4/28/02 event:

Yesterday's tornadoes had the potential of causing a large number of deaths. While the "Suffolk tornado" was larger than what most people anticipated, there was a Tornado Watch box that was followed by Tornado Warnings. SPC, NWS and local media in the area provided *excellent* service to the public and deserve recognition for mitigating loss of life. I'm a member of SkyWARN and was unable to chase but have exchanged text messages with a cohort in Hampton Rhodes, VA. Trained spotters and chasers in these parts don't often cover a violent twister, but those who did yesterday did so professionally and provided critical ground truth. We should tip our caps to the professionals and volunteers who helped prevent catastrophic casualties here in Virginia.

Suffolk, VA Tornadoes Reportedly Injure over 200 People & Produced Significant Damage.
Monday, April 28

Tornadoes in Brunswick County and the City of Suffolk, VA late this afternoon have produced significant to major damage. As this is written (7:15PM), a Tornado Watch remains in effect for extreme SE VA and NE NC.

The tornadoes developed around 3:30PM this afternoon and were associated with storms ahead of a Cold Front crossing the interior Mid-Atlantic States. There are reports of two tornadoes crossing Suffolk, VA and I've seen one picture of a multiple vort tornado so we'll see how the damage path looks to NOAA personnel who now are investigating.

It is nearly impossible to determine the strength of a tornado without examining the damage, but I can tell you the event in Suffolk produced very significant damage as evidenced by this photo from WAVY.com:

When all is said and done I'm certain this will be an EF-3 tornado...at least.

Today's storm report map (click graphic for more data)

Thus far, three tornado touchdowns appear to have occurred in SE VA...not unheard of but somewhat unusual except during landfalling hurricanes or tropical storms. What is unusual is the probable intensity; most twisters in the Mid-Atlantic range from EF-0 to EF-2. An EF-3 is significant while an EF-4 would be rare.

Good local coverage (including raw videos) out of Norfolk, VA on WAVY.com. My daughter attends college in the area and I spoke with her this evening; she reported rain but nothing severe at her campus so her Dad is grateful for that news.

Widespread severe weather is not expected for the region tonight although snow may accumulate over the western slopes of the Alleghanies early Tuesday morning. A few flakes could fly over the Virginia Highlands but no accumulation is expected. Temps rebound into the 60's and lower 70's later this week for the region.

Quick Clipper Exits Before Easter Cool Down and Struggling Spring...And...
More Amazing Pics!
Friday, March 21

An Alberta Clipper now crossing the Lakes, where a band of 4-6 inches of snow will accumulate, will cross the Mid-Atlantic tomorrow with little fanfare. We'll keep all frozen precip from the Clipper north of the Mason-Dixon Line while saying some back side snow flurries may fall late Saturday over the Alleghanies. Otherwise, modest amounts of snow for PA with a narrow rain/snow mix nearer the NJ coast.

High Pressure will build in over the Mid-Atlantic States behind the departing Clipper. This I find irritating given the sparkling weather we've enjoyed today. Easter Sunday morning should be quite cool to downright cold. Highs on Sunday and Monday will be in the 40's to low 50s as the High overspreads the region with chilly air. Night time Lows return to the 20's and lower 30's from west to east.

The costal Low some models were advertising will develop...but will do so well off-shore and quickly head out and away from land. Therefore, this system will not produce The Mother of All Easter Snowstorms for the Northeastern US. A shortwave will move into the region and a little wintery precipitation can be expected late Sunday night and Monday morning as precipitation will fall in chilly air. Right now it looks like light snow will more into the Mid-Atlantic on Sunday night for locations north of VA I-64 (Staunton-Charlottesville-Richmond) and down the I-81 Corridor. Onset may be delayed due to dry air in place with early precipitation evaporating before reaching the ground (virga). There could be a coating of wet snow and perhaps pockets of freezing rain but no significant accumulation is expected and all areas will warm to above freezing by late Monday morning. This is one of those nuisance variety winter irritations! South of VA I-64 and along the coast this will be a wet and not white event...possible exception is Charlottesville-Lynchburg-Farmville areas could see a touch of freezing drizzle with some wet snow flakes.

Temps rebound midweek as rain approaches late Thursday with another frontal boundary.

COOL PIX:

This is an absolutely stunning picture believed to show the March 14 tornado entering the City of Atlanta:

Click Picture to Enlarge

When I first saw this picture it was without credits and honestly thought it to be an urban legend Photoshop hoax. The photographer provided the picture to "11 Alive" in Atlanta and has been featured on the web site of Atlanta basted Talk Radio host Neal Boortz. The ominous dark clouds in the foreground appear to be a Shelf Cloud while lightning illuminates the rain shaft in the center of the image. Look above the bright building on the left side of the picture: it is believed that shaft is the tornado approaching downtown. Wow! Thanks to Troy over near Charlottesville, VA for sending in to Mid-Atlantic WX.com

This storm system produced an area of Low Pressure off the Southeast coast that raced away and quickly intensified last weekend. Here's what the storm looked like from space last Sunday:

Click Picture to Enlarge.

You may think that's a hurricane but in reality it is a very intense non-tropical Low Southeast of the Canadian Maritimes.

I'll get these amazing images into our Photo Gallery this weekend.

March weather always is exciting! Have a happy and safe Easter Weekend.

Severe Storms Possible Today. And...How About an Easter Snowstorm?!?!
Wednesday, March 19

Sunday's blog below has verified nicely so far so this will be a quick advisory with no big changes to original ideas.

Double barrel Low Pressure over TN/KY this morning tracks into eastern Ohio Valley this afternoon and then the Northeast early Thursday. High Pressure over the SW Atlantic will weaken and shift, allowing moderate to heavy rain to finally overspread the Southeast and Mid-Atlantic States. Warm and juicy air from the Southwest is being squeezed up between the Cold Front and the SE Ridge with morning temps well up into the 50's and 60's across the region.

Severe weather parameters are not supportive of a widespread outbreak of dangerous weather today...however...moderate to heavy rain and some thunderstorms are likely. The extent of severe weather probably lies in a very narrow band of storms expected to fire just ahead of the Cold Front late this afternoon and early evening. Best bet right now is for broken lines of storms later today over eastern KY/TN and WV, moving over west-central NC and VA. There's a slight threat of an isolated tornado however heavy rains and damaging winds should be the biggest risk factors later today. Check our convective outlooks from SPC by clicking HERE.

Check in with our Severe WeatherCenter for real-time information during the day.

EASTER SNOWSTORM?: As opined in last Sunday's blog, there's a possibility for "interesting" weather on Sunday. Models still dueling but the trend is toward a *significant* snow event for the Northeast...possibly the Mid-Atlantic States. I'll have a full discussion on Friday but be sure to check forecasts and information here at Mid-Atlantic WX.com if you have travel plans for Easter weekend!

Midweek Mid-Atlantic Storms? And A Look Ahead to Easter Weekend.
Plus...Tornado Follow-Up and Why I'm a Proud Yankees Fan!
Sunday, March 16

Low Pressure that triggered this weekend's significant severe outbreak is heading northeast well off the VA/NC coast. High Pressure centered above the Great Lakes will build down into the Mid-Atlantic and Eastern US today, brining calmer, breezy weather and cooler temperatures. Clearing skies and Canadian High Pressure will drop overnight temps below freezing for the entire region north of the VA-NC border.

A buckle in the northern Jet Stream now over Southern California will kick a storm from the Southwest and increase the risk of severe weather tomorrow for south-central TX. This dip in the Jet Stream will produce a negatively-tilted trof over the Central US and while models are not in total agreement, strong storms may fire up over Louisiana on Tuesday. Low Pressure associated with this system will migrate toward the Great Lakes on Tuesday...pushing a Warm Front into the Mid-Atlantic area, quickly followed by a Cold Front as the system passes by. Rain will overspread the TN and OH Valleys before reaching the Mid-Atlantic States on Wednesday. There is a chance of strong to severe thunderstorms developing ahead of the Cold Front on Wednesday afternoon...particularly over the Carolinas and Georgia (areas hit by this weekend's severe outbreak). I'll monitor and update the blog as necessary, but keep an eye on Wednesday's forecast.

The departing storm opens the door for High Pressure to return and with it, a drop in temps to near of slightly below normal levels on Thursday and Friday.

Curious potential next weekend. An Alberta Clipper will come down but should be moisture starved. Interestingly, most Clippers this winter have tracked South of the Ohio Valley and Mid-Atlantic and this one should, too. Easter Weekend weather still "iffy" for Central US, especially if the usually reliable European (ECMWF) model is right and we have deep Low Pressure on Easter Sunday over the Central Plains!

After a "couple days off", the active and stormy cycle of storms that is typical for March should resume this week and extend into the final week of the month.

Atlanta Tornado Follow-Up:

I received this picture last evening:

This photo shows exterior damage from a building in downtown Atlanta. I was asked to identify the three metal objects "stuck" on the side of the building and offer speculation as to what punched a hole in the exterior wall and knocked out the window. I have no idea! The structure appears to be of concrete masonry construction... whatever hit the building did so with great force. I've not seen this photo elsewhere and did forward to the National Weather Service. This image shows you what a "minor" EF-2 is capable of doing. Odd for a storm chaser to say but this is more proof of why you never want to be outside or near a window as when a tornado approaches. Thanks go to Annie in Kershaw, SC for sending in this stunning photo.

Let's Go Yankees! If you've read this blog for any length of time you know I am a lifelong New York Yankees fan. Tuesday (3/18), the Bronx Bombers play a benefit exhibition game with the Virginia Tech Hokies baseball team. Tickets were not available to the public and all proceeds benefit the Hokie Spirit Memorial Fund. The Yankees have already made a one-million-dollar gift to this fund and this game will generate additional financial support for this endowment. Perhaps as important, the Yankees bring Megastar excitement to a campus still recovering from the events of April 16, 2007.

Try as I did, no tickets for me so I'll watch the game on local TV. Here's a link for broadcast outlets over the air and on the Internet: http://www.hokiesports.com/baseball/recaps/20080306aaa.html. I know a HUGE percentage of my friends and those who read the blog absolutely detest the Yankees and that just the way we fans like it!!! I do hope even the Yankee haters will appreciate what the team has done to support VT and how exciting it is for the local area and Hokie Nation.

This game reminds us we'll soon be hearing: "Play Ball"!

Severe Storm Hits Downtown Atlanta On Friday Night...Tornado or Macroburst?
MODERATE Risk of Severe Storms in GA-SC Today.
Saturday, March 15

UPDATED: 11:55AM: The National Weather Service has confirmed last night's storm affecting the Metro Atlanta area was an "EF-2" tornado. Preliminary assessment indicates tornado damage along a 6 mile path, 200 yards wide. This is the first tornado to affect the City of Atlanta.

Additional severe weather possible today...more in this morning's original blog below.

MODERATE RISK TODAY: Much of Georgia and South Carolina are under a Moderate Risk for severe weather today. Folks in the affected area should monitor reliable local media and have a NOAA Weather Alert Radio handy. Visit our Severe WeatherCenter for real-time information. Slight Risk of strong storms spreads north into North Carolina later this afternoon and evening.

The severe storm that moved literally over downtown Atlanta last night has produced extensive damage and as of this morning, 20 injuries but no known fatalities.

I've been watching "11 Alive" from Atlanta as they continue nearly wall-to-wall coverage: here's the link for live streaming video: http://www.11alive.com/video/default_live.aspx?storyid=112936

I was in Atlanta late January and recognize many of the familiar damaged landmarks downtown now showing damage on TV. Amazing to see damage at the Georgia Dome, windows blown out of the CNN center and furniture sucked out of rooms at the downtown Omni Hotel.

Looking at last night's Radar, it's clear a severe thunderstorm moved into the Atlanta Metro but until the NWS officially inspects the path and damage one can not "officially" say this was a tornado. I'll tell you a hook echo forming on Radar loop certainly supports the belief a tornado was developing as the storm approached downtown. My hunch, based on ground and aerial video this morning is the NWS will find either "EF-2" tornado damage or classify this as a non-tornadic Macroburst. A Macroburst is a powerful downburst of damaging winds over an area greater than 2.5 miles (a Microburst has a diameter of less than 2.5 miles).

Fascinating audio and video is found in the video below, taken during the Alabama-Mississippi State SEC basketball game at the Georgia Dome. You can hear the oft-mentioned "freight train" sound of wind people used to describe a tornado. However, this is similar to what occurs during a macro or microburst and is not audio evidence of an approaching tornado. In a macroburst, a large column of air accelerates downward and upon reaching the ground it spreads out in all directions. This type of outflow "roars", especially as it passes through trees and developed areas. But, Rada leads me to believe this will be an EF-2 tornado. Click the video below and imagine you were in the Georgia Dome as this was occurring:

A final comment on what the NWS is looking for. Macroburst damage is caused by straight line winds radiating out from the center of the downburst. Tornadoes, in contrast, tend to produce damage that rotates inward toward the exact patch of converging winds.

I've been in several microbursts and one macroburst and, yes, they do produce very strong winds...often over 100MPH! So, we'll wait and see what NWS finds over the next day or so.

RANTS: Atlanta Mayor Shirley Franklin said in a press conference late last night there was "...no warning".
That is not correct:

BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING  
NATIONAL WEATHER SERVICE PEACHTREE CITY GA  
930 PM EDT FRI MAR 14 2008  
  
THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A  
  
* TORNADO WARNING FOR...  
  CENTRAL FULTON COUNTY IN NORTH CENTRAL GEORGIA  
  
* UNTIL 1000 PM EDT

The NWS Forecast Office indeed did issue a "short-fuse" warning and while the Mayor may not have known, the NWS
did their job and was disserved by her inaccurate comment. She needs to reassure Atlantans by publicly apologizing 
to the National Weather Service. If you viewed the video above you heard no mention of a Tornado Warning until the 
storm had passed downtown! While announcing "Tornado Warning" in a packed public arena is frightening, the
alternative is far worse. The Weather Channel is a joke. Fox News and CNN had more extensive coverage than did TWC.
It seems they now pre-record much of their on-air content and have no one available to cover a severe weather 
event that is affecting tens of thousands of people, literally down the street. I gave up on TWC years ago and so 
should you. Pathetic.

I'll be back tomorrow with a look ahead to next week's weather.

Quiet Week Before a Saint Paddy's Storm...And...
My Mini-Chase and Major Rant.
Sunday, March 9

[Truth in advertising: this was written late Sunday but published after Midnight so I kept the dateline as March 9, 2008]

A ripple of Low Pressure rolls through the Mid-Atlantic States tonight and Monday and may bring some mixed precip or a little light snow to PA up to southern New England. A very weak Cold Front approaches Monday night with the chance for light sprinkles or a wayward snow flurry over the Appalachians...otherwise a quiet start to the work week. High Pressure builds back in on Tuesday and temps climb to above normal reading with clear skies and rather "boring" weather.

Another system approaches late Thursday, but should bring only rain to the region as temps will remain quite mild.

A potent storm will crash into the Pacific Northwest later this week and could impact the Mid-Atlantic region just in time for St. Patrick's Day. I'll not the NAO Ensemble is forecast to go negative for the first time since mid-December...this teleconnects with the strength and timing of the Pac NW system. Models are generally pointing to Low Pressure diving down toward Texas late week and then moving off the Mid-Atlantic Coast before heading toward the Northeast this weekend. Right now it looks like rain with the possibility of scattered minor thunderstorms on Saturday. Sunday certainly looks like the better day next weekend with clearing skies and temps generally in the upper 50's to lower 60's. Interior Northeast could see mixed or winter precipitation but that is not certain at this time.

As this is a weekend event, I'll update the blog on Thursday night and invite you to stop by at that time.

MINOR RANT ABOUT OVER-HYPING SEVERE WEATHER: Last Tuesday night I was able to get out and try to chase. Travel was modest due to weakening storms within quick driving distance from my office in Lexington, VA (not the tornado capital of the region!). I did intercept a storm near Bedford, VA that prompted a radar-indicated Tornado Warning, but found no funnel despite some rotation. Afterwards, while waiting for another chaser, I checked VCAST Video on my Verizon cell phone. Wow! I had no idea what I've been missing! Apparently, Verizon has a deal with WeatherBug to stream recorded daily weather briefs. Last Tuesday's video indicated the Southeastern and Mid-Atlantic US were in store for "...EF-2s, EF-3s, EF-4...possibly even EF-5's". Really??? Meanwhile, the video went on to say the storm's cold sector would produce "a half inch to one inch of ice" for the Ohio Valley" Holy Cow...I'm in-between EF-5s and freezing rain accretion of one inch. What a storm!

Well, there were no EF-3s,4s or 5s, nor were any ever forecast (there was one minor TOR in Alabama, I believe). And that one solid inch of ice? Nope, never forecast and did not happen (do you know how devastating one inch of ice would be?). I don't mean to pick one anyone, however, this was the single biggest example I've ever seen of over-hyping severe weather. Last Tuesday's event was significant and produced a wide swath of severe weather...especially in early March. But, "forecasting" massive intense tornadoes in areas where they rarely occur is not prudent and unnecessarily alarms people. Thankfully, major tornadoes in the East are extremely rare: multiple F-4s occurred across the Carolinas in 1989 and the most recent F/EF-4 was near La Plada, MD during the Mid-Atlantic Outbreak in April, 2002. One must go back to 1985 for the most recent Eastern US F/EF-5 tornado which caused immense destruction near Wheatland, PA.

Only 20% into 2008, 66 tornado fatalities have been recorded, already making this a very bad year. Those entrusted to forecast and discuss weather have a duty and responsibility to impress upon the public the threats of a severe event without exaggeration and hype.

Mid-Atlantic Moderate Risk for Severe Weather Today! First Tornado Watch in Effect.
Tuesday, March 4

Real-time current Tornado Watch(es) seen below in dark red. Click graphic for enlarged view).

Severe threat expands today as a strong upper level storm (ULL) and Frontal Boundary approach the area today. Slight Risk area highlighted in yellow below. The MODERATE RISK zone outlined in red. Click graphic below for more maps showing wind, hail and tornado threats.

A potent squall line should develop this afternoon...particularly strong over the Carolinas and perhaps up into the Piedmont of VA (south of Charlottesville). Areas with some sun will see enhanced severe parameters and Supercells can not be ruled out, thus the concern over tornadoes. While tornadoes are possible along bow lines, these "bow Echoes" typically produce weak and relatively short lived twisters. Different story with Supercells and this is what will be closely monitored today.

I'm also watching where the rain and clouds are located ahead of the frontal boundary. The western Carolinas and VA have been socked in all morning and these clouds and rain may well put the kibosh on severe weather this afternoon. This lines up nicely with how SPC is forecasting this afternoon's Slight and MODERATE risk areas. In general terms, this should be a heavy rain event west of the Blue Ridge (I-81 Corridor) and north of VA I-64 from Staunton-Charlottesville-Richmond, VA. South of this area...especially if there's some afternoon heating and a squall line develops...very strong storms are possible with hail and damaging winds. Again, highest tornado threat is for the Carolinas, west of I-95 as well as extreme south central VA.

Timeline for severe weather is 4PM-10PM as the front will clear the region by Wednesday morning.

Spring is a good time to review your personal preparedness for tornadoes: get tips by clicking HERE
As always, our Severe WeatherCenter provides you with real-time information.

I have the "chase gear" ready but doubt I'll be able to get very far out of the I-81 Corridor today...so please check back this evening for an update on the season's first Mid-Atlantic severe weather threat.

UPDATE, 6:55PM: Excellent discussion from the Storm Prediction Center nicely sums up risk for tonight:

DISCUSSION...VERY INTENSE VERTICAL MOTION FIELDS AND LOW/DEEP LAYER SHEAR WILL OVERSPREAD THIS REGION THROUGH TONIGHT AS STRONG UPPER SYSTEM BEGINS TO LIFT NEWD ACROSS THE APPALACHIANS. ALTHOUGH INSTABILITY WILL REMAIN MEAGER...MOISTENING LOW LEVELS CONCURRENT WITH 70+ KT SLY LLJ WILL ENHANCE THE POTENTIAL FOR LOW LEVEL ROTATION AND POSSIBLE TORNADOES. ACTIVITY MAY OCCUR IN TWO BANDS...ONE NOW MOVING INTO CENTRAL NC/VA AND ANOTHER SPREADING ENEWD ALONG THE MAIN COLD FRONT LATER TONIGHT. SEVERE/TORNADO THREAT MAY PERSIST WELL INTO THE NIGHT UNTIL THE LATER BAND MOVES OFFSHORE.

(Emphasis added by me). This second line of storms referenced by SPC is holding together but could weaken somewhat later tonight. However...this pre-frontal squall line is inside a dry slot ahead of the Front...between the offshore High and the Upper Level Low currently over Kentucky. For this reason, extreme caution is urged tonight in the expansive Tornado Watch area. Flood Warnings also popping up over WV as heavy rain continues over snow pack and could produce dangerous night time flash flooding!

If I don't head out to meet up with chasers, I'll be online this evening...check my AIM IM box on the left. If I'm online, please let me know about your weather.

First Severe Threat For Mid-Atlantic Arrives Tuesday...Followed by a Nor'Easter!
Monday, March 3

Temperature roller coaster continues this week...but we're definitely on the upswing. Strong winds racing up from the southwest today will bring temps to well above normal levels ahead of an approaching Cold Front. Warm moist air from the Gulf collides with cooler and dryer air behind the front will produce severe weather along the north-central Gulf coast, FL Panhandle and into GA today.

Low Pressure will track across the Tennessee and Ohio Valley on Tuesday, moving toward PA on Tuesday night. Intense storms should continue overnight and into Tuesday morning over the FL Panhandle and into AL and GA...torrential rain and some tornadoes are probable.

Mid-Atlantic States currently in Slight Risk zone from Storm Prediction Center and my hunch is this will be tweaked on Tuesday to include an upgrade to MODERATE RISK...probably for portions NE GA, much of SC and coastal NC...and perhaps SE VA up to Norfolk/VAB Check our Severe WeatherCenter for real-time information. Strongest storms move from the SEUS into the Carolinas late Tuesday morning and into the afternoon. Severe parameters indicate the greatest threat is from damaging winds...however...tornadoes are possible! As the frontal boundary approaches a squall line is expected to develop, producing some thunderstorms and very heavy rain. In the areas outlined above, there should be sufficient sunshine and daytime heating to enhance the potential for Supercell development...heightening the threat of tornadoes on Tuesday afternoon. l This system will have the potential to continue producing damaging weather as it has today and persons in the potentially affected areas should monitor reliable local media and keep an eye on our Severe WeatherCenter.

North and west of the strongest storms will see rain with rumbles of thunder Tuesday afternoon and evening and damaging wind gusts will be possible. Rainfall of one to two inches is also possible in areas will frozen ground and snow cover; as a result, numerous Flood Watches have been posted.

Behind this severe threat looms a reminder it is early March. Low Pressure will shoot out of the Gulf of Mexico on Thursday and intensify as it reaches Savannah, GA on Friday. Current setup supports a growing computer model consensus this becomes a Nor'Easter this weekend! First guess right now is rain for the SEUS and along the coast up to NYC. a swath of mixed/freezing precipitation should develop late Thursday or Friday from Philly down to the Metro Washington DC area and along the Appalachians. West and north of the wintry mix will be snow...possibly heavy snow! The track of this pending Nor'easter is uncertain but it does appear the Mid-Atlantic will see mostly rain with mixed precip for the mountains and perhaps the I-81 Corridor. We'll need to tune up this discussion with a discussion here Wednesday night or early Thursday.

Keep an eye out for severe weather tomorrow...especially if you are located or traveling in the eastern/coastal Carolinas or southeastern VA.

Ready For The Rollercoaster?
Sunday, February 24

A little wet snow and rain at our weather office tonight...that is moving east over the region as an Upper Level Low (ULL) swings through the area overnight. Not much of an event as snow/ice pellets/rain will be scattered over the Mid-Atlantic into Monday morning.

High Pressure comes in for a 1-night stand; providing a mini-warm-up Monday and Tuesday featuring temps at or above normal, thanks in part to a Warm Front zipping through in front of our next weather maker. Low Pressure now over Colorado reaches Ohio by Tuesday afternoon before aiming at Portland, Maine on Wednesday. This storm's Cold Front will cross the Mid-Atlantic on Tuesday and most of the East and South will notice Wednesday temps 15 degrees colder than Tuesday's!.

The storm's track is not conducive for snow along the coast south of Portland, so we'll go with rain for the I-95 Corridor. Northern PA, Upstate NY and most of interior New England are braced for another bout of winter weather with widespread accumulations exceeding four inches.

Western slopes of the Appalachians will again see several inches of accumulating snow late Tuesday into Wednesday morning. East of the Appalachians, there should be little to no snow as the system will pass to the northwest. I can't rule out a wayward flurry late Tuesday night from the foothills to the Blue Ridge, but no accumulation is expected.

All this is subject to change with the actual track making a slight shift to the south. Right now it doesn't appear that will happen, but I'm certainly watching for the possibility of this sneaky development.

I've been watching the European model (ECMWF) which has been steady as a rock on the forecast for the balance of the week. The "EC" is the preferred medium-range model...especially in winter. Very cold air moves in on Thursday with temperatures colder than Wednesday. I'd expect Thursday to average ten degrees below normal, even with sunny skies. Temps moderate Friday and Saturday as another storm approaches but misses the Mid-Atlantic and tracks into the Northeast and could pull in some light rain or a little snow for locations south of the Mason-Dixon Line. This doesn't appear to be an impressive event but it is 6 days away so we'll watch and see.

I Dub Thee: "The Moses Storm of 2008".
Friday, February 22

Tropical storms and hurricanes have names while winter storms do not...at least "officially". We weather people have our own names for winter events. One need say only "President's Day" to know this is the February blizzard in 2003. Then, there's the "Pamela Anderson" storm of 2001; aptly named as it was the biggest bust observed in years! Well, by the powers invested in me, by me, I now name today's underachiever as The Moses Storm of 2008.

Not since Moses parted the seas has such a split been observed on Earth! While there were pockets of freezing rain, much of North Carolina and most of Virginia south of I-66 awoke this morning to nothing...no snow, sleet or freezing rain. Roads were generally wet but clear. Every model, apparently every NWS office, private weather company (you know who I mean!) and numerous meteorologists totally missed this one. And, we'll put yours truly in that category, too!

What happened?

To oversimplify, 2 things: 2 Lows and thunderstorms.

High Pressure over the region indeed set up a wedge across the area just as forecast. Last night's Sea Level Pressures across Virginia and the Delmarva were around 30.20" and dew points away from the coast hovered in the low to mid teens, resulting in a cold, dry air mass at and just above the surface. I noticed numerous wet bulb readings in the area remained several degrees below the dry bulb (actual) temperature...another clue precipitation will struggle to reach the ground.

Next, the precipitation came in two separate pieces; one moving into the Ohio Valley and the other toward the Southeast coast. Precipitation indeed moved up into the Mid-Atlantic however cold, dry air absorbed much of it prior to reaching the surface. Here's the Thursday evening National Radar composite at 6PM EST:

The two distinct areas of precipitation are easily observed...with Virginia right in-between! Normally, the precipitation falling over the Southeastern US would move northeast...toward the Mid-Atlantic States. Cold air at the surface with advancing warmer air and moisture aloft is the reason many regional forecasts featured snow/sleet changing to freezing rain. But...take a closer look at the Texas/Louisiana border and the Florida Panhandle in the image above. What do you see? Thunderstorms!

So did the Storm Prediction Center; they issued several severe thunderstorm and tornado watches. Here's a Tornado Watch prompted by the TX/LA cells seen above increase and cross Louisiana:

Now, what do thunderstorms in the Deep south have to do with freezing rain in the Mid-Atlantic? The answer is everything!

Convection near and along the north-central Gulf coast will frequently "rob" the Mid-Atlantic of precipitation and that's what happened last night and this morning. As powerful storms fired up from Louisiana to Florida, one could observe this moisture transport in water vapor loops. Rain destined for the Mid-Atlantic diverted instead to powerful storms closer to the Gulf.

This very development is something I've preached for years: with every southern stream storm, don't watch Radar from the Mid-Atlantic or Northeast, watch it from the Gulf Coast. While keeping an eye on water vapor loops and National Radar I noticed the amazing "parting" of the storm's precipitation and was most surprised. Then storms fired up and the SPC dispatched watches and warnings along the Gulf and, well, as Col. Potter always said on M*A*S*H: "that tears it!" I knew this event would bust for north-central NC and much of VA and the Delmarva.

I was never gaga over this system's potential to become a major storm south of the Mason-Dixon Line. Snip from last Sunday's discussion (below ) from the blog: "Low Pressure shoots out of Four Corners and Texas as the Southern Stream gets cranked up...hence...the potential for southern stream moisture over running cold air at the surface. This combination brings a *low confidence* potential for inland snow and freezing rain for Thursday night and Friday."

Elsewhere, forecasts were good...with accumulations of 3 inches plus for Philly and nearly 10 inches for interior Southern New England. But, in Virginia south of NOVA and the I-66 Corridor, this will be "The Moses Storm of 2008"!

I'll be back Sunday for a look at the last week of February. Out like a Lion...or a Lamb? Stay tuned!

Wintry Weather to Feature Ice for Portions of the Mid-Atlantic.
Wednesday, February 20

Tonight's surface map shows Low Pressure over Texas along a Cold Front stretching to Norfolk/Virginia Beach, VA. High Pressure over the Upper Plains will build into the region on Thursday with much colder temperatures. The Texas Low will approach the Mid-Atlantic later Thursday. Light-modest snow totals coming from Northern OK into OH...perhaps 3 to 5 inches..

Freezing rain and plain rain fall just south of this area, prompting travel delays and road hazards on Thursday. South of the freezing rain/rain mix will be all rain.

Mid-Atlantic States again the bulls-eye for a wintery mixed event! High Pressure will move east and set up a cold air wedge (CAD) east of the mountains. This cold air will be trapped at the surface with warmer air and rain aloft. This over running should trigger freezing rain and very cold rain from north central NC, Southside VA, the New River and southern Shenandoah Valleys...as well as the Piedmont/Central VA area west of I-95. Timing is a bit problematic, with the NAM and the GFS at odds by several hours but would think precip begins reaching the ground late Thursday afternoon in NC and Southside VA...moving north overnight Thursday into Friday morning. Northern VA (NOVA) and points north should be mostly snow although the I(-66 Corridor from Winchester over to Arlington may quickly transition to freezing rain. Metro Washington-Bal-Philly will mostly be freezing rain. Much of PA should be all snow with totals generally in the 2 to 4 inch range. Southern Tier of NYS and interior southern New England could see higher accumulations.

Late Thursday and much of Friday will be the worst travel times in Mid-Atlantic. Check our Winter StormCenter for real-time information.

Brief discussion tonight as the Lunar Eclipse is underway and the clouds have broken away at my location. I'm heading out!

Cold and "Interesting" Week Ahead.
Monday, February 18

Not much in the way of new ideas from what was discussed here yesterday. Low Pressure dives under the Great Lakes and approaches the Mid-Atlantic this week. This should be a typical Alberta Clipper type system with light snow Tuesday and Wednesday morning for the Lower Lakes States (not a LES storm). Upslope snowfall may reach 4-5 inches for the western slopes of the Alleghanies of WV with very dry flurries possible from the mountains to the Blue Ridge and also north of the I-66 Corridor. A dusting is about all that's expected although 1-2 inches may sneak in over MD, DE and lower PA. The atmosphere will be very dry and negligible accumulation expected east of the mountains.

Windy with below normal temps for the balance of the work week as Southern Stream storm heads west of the Appalachians with a secondary Low forming off the Mid-Atlantic coast late Thursday. Cold air is expected to be wedged over the region and NC and VA again become the battle zone for winter precipitation. Snow will be the main precipitation type from the Central Plains into the Northeast with a smaller stripe of freezing rain/sleet across the TN Valley.

There's no shortage of options on the table but one I do not believe will verify is significant snowfall south of the Mason-Dixon Line. We'll have a wedge of cold air bottled up and a great deal of moisture transported in on the southern jet but I believe the primary Low tracks well west of the Alleghanies...pushing warmer air from the southeast into NC and Virginia. We'll see how this sets up but this would initially lead one to suggest freezing rain as a viable option. Next player is how strong does the coastal Low get...and how far off-shore does it track. Too soon to say with precision.

Keep an eye on your local forecast and the Winter StormCenter here at Mid-Atlantic WX.com this week.
I'll try to get an update here on Wednesday night.

Ice Storm "Big Fizzle"...Some Severe Possible Monday...Winter is Back Next Week?!?!?!
Sunday, February 17

No blogs last week due to traveling, but now back in the saddle. Last Sunday's frontal passage and associated widespread wind storm led me to my first ever "tree and roof chasing day"! I lost power for the better part of nine hours (no blogs) and devoted the day to calling in the diameter of downed trees to the NWS, along with "chasing" reports of roofs blown off buildings and overturned outbuildings. I've been a SkyWARN Spotter for many years but that was the first time I went looking for trees rather than dodging them! While on-the-road, my youngest daughter sent me a text indicating a large pine tree came down in the backyard and bent the flagpole:

Yesterday was the first opportunity to remove the tree and clean up the yard! Last Sunday's event produced a wind gust of 62MPH with sustained winds of 55-58MPH at our wx station in Lexington, VA; this was the third highest non-thunderstorm wind speed observed since the wx station went into operation in 1996.

TODAY: Excessive warm air advection eliminated any threat of freezing rain. Widespread morning temps at or above 40° along with dry air at the surface delayed onset of any precipitation, and that fell as plain rain.

MONDAY: Curious set up for tomorrow: a Warm Front will bulge up into the Mid-Atlantic immediately in front of a rather sharp Cold Front. The low level jet stream will howl and if there is sufficient instability with these two fronts there could be strong to severe storms Monday morning and early afternoon. As noted by the SPC, threat will be east of I-95 and south of the Chesapeake Bay. Lines of heavy rain and strong winds would likely be the most notable features.

Monday afternoon, the Cold Front pushes through and any severe threat will diminish...as will the temperatures! Winds will increase out of the W-NW and temps will tumble by Monday night.

WINTER RETURNS NEXT WEEK? Prepare for a very active weather pattern! First up, an Alberta Clipper should advance late Wednesday or Thursday morning. all appearances now are this will be moisture starved by the time it reaches the Appalachians...but western upslope snow is not ruled out. West of the mountains back to the Lower Lakes, accumulating snow is a good bet...perhaps several inches in favored Clipper/LES locations.

Temps Wednesday evening into Friday will be well below normal as High Pressure builds in behind the Clipper, then sets up over the Northeast next weekend. Winds will shift to the East and we then must consider the development of cold air damming (CAD) wedge. Meanwhile, Low Pressure shoots out of Four Corners and Texas as the Southern Stream gets cranked up...hence...the potential for southern stream moisture over running cold air at the surface. This combination brings a *low confidence* potential for inland snow and freezing rain for Thursday night and Friday.

One potential monkey wrench in all this is how strong with the Southeast Ridge be...and where will it set up by next weekend? If high pressure strengthens over the SW Atlantic the door is open for warmer air to ride in with the advancing Southern Stream storm. Translation: probably rain with the potential for interior freezing rain. Right now, I do not see a way for cold air to lock in so I'm skeptical of a late week snow event south of the Mason-Dixon Line.

Progressive pattern continues next weekend but temperatures should be at or a bit above normal by Sunday (2/24).

I'll briefly update the blog tomorrow (Monday) evening after the Cold Front passes...I'm curious as to how the models will will "see" how much cold air is coming in and how the Southeast Ridge is being handled. Please check back then...and stay tuned...an interesting week is upcoming!

Storms and Damaging Wind Approaching the Mid-Atlantic Today.
More Tornadoes Possible.
Wednesday, February 6

I can't recall a more devastating February tornado outbreak than what occurred yesterday and last night. Death toll now at 45 and certain to rise with today's morning light. This is always the aspect of extreme weather that makes those who are so passionate about it pause and reflect. Sometimes, knowing how many DID survive because of faster warnings and quality storm chasers just isn't enough.

Impressive hail from a tornadic storm last night near Nashville, TN:

I believe there is a possibility portions of the Mid-Atlantic will upgrade to a Moderate Risk today.

Current outlook:

Severe parameters are reasonable for strong storms to fire up just ahead of the Cold Front rapidly approaching the region. Soundings show instability with marginal CAPEs and low LIs along with some shear...if there's sufficient sun to heat this extremely warm and moist air (amazing for early February), the cap will break and strong storms quickly get going. For this reason, caution is urged and everyone in the "Slight Risk" areas highlighted above should stay close to NOAA weather radio and reliable media for quick information. Of course, our Severe StormCenter is the place to be for real-time warnings and information.

Parameters do not support the intensity and longevity of yesterday's outbreak...however very strong storms can develop especially where sunshine heats up the lower levels and raise dew points already in the 50's and lower 60's. These storms will be capable of producing very strong straight line winds and downbursts of wind and heavy rain. Hail doesn't appear to be a significant threat today but we can't rule it out, particularly in strong to severe storms. Tornadoes are possible and you'll want to remain alert for the potential of tornado watches migrating into the Virginias and Carolinas today.

Target zone as outlined by SPC this morning is Western MD, extreme eastern WV and Virginia down the I-81 corridor and west of I-95...but...includes the Metro Washington DC-Baltimore areas, I-66 and the Beltway..as well as Richmond. This set up often produces tornadoes along the I-66 corridor from Winchester to DC...something to watch for today.

Timeline looks like early afternoon for WV with severe weather potential peaking around 5-6PM along the Blue Ridge Mountains. Storms should be firing east of the Blue Ridge this evening, weakening as they pass I-95 as the Cold Front pushes off shore.

Please check your local forecast and monitor real-time conditions and any weather watches and warnings at our Severe StormCenter.

12:00 NOON UPDATE: Severe threat has diminished in the Mid-Atlantic. Extensive cloud cover from debris clouds in the outflow of last night's storms is keeping much of the region out of the sun. Temps and dew points also are dropping. as showers and rain cross the mountains.

This changes previous thinking on the timeline and risk level of severe weather. Looks like this outflow will provide a moderate-high level of cloud cover over the region into this evening and as such, the cap probably remains on and there will be little to no low level convection. The Surface Low is projected to move up into the Ohio Valley before tracking into western PA tonight. The strong Cold Front will drag to the south of the Low and this may be the focus of activity. Most of the system's energy appears to be along the frontal boundary and with the Low...therefore strong to severe storms may still fire up tonight as the boundary approaches the Appalachians. I am concerned there could be severe weather between 5PM and 11PM...time frame for the Cold Front to cross the Mid-Atlantic states.

Obviously, night time severe weather is a special concern and skies could become more clear as the front approaches. Without daytime heating the lower levels will be more stable but there's a tremendous amount of mid-level energy coming that will be capable of producing strong storms. This dry slot shows up nicely on the animated Water Vapor Loop...click here. Add in veering winds aloft and there remains some threat for tornadoes as the Front approaches the area. It is important to note SPC has significantly reduced the tornado threat for the Mid-Atlantic...but we are not out of the woods!

Very hectic schedule as you may imagine but I'll try for a quick update here at the blog late this afternoon.

Super Tuesday Tornado Outbreak!
Tuesday, February 5

Severe storms are producing numerous confirmed large tornadoes ahead of an approaching Cold Front. Storm Prediction Center nailed a rare HIGH Risk area today for AR-W TN/KY and N MS. Long lived tornadoes have been on the ground in Arkansas and severe damage has been reported near Memphis, TN. Reports streaming on WMC-TV indicate a shopping mall just outside Memphis has been hit...along with a manufacturing plant and warehouse. Video I've seen indicate this could have been a major EF-3 tornado, but that's an unofficial opinion. Damage is reported along I-40 and at Union University at Jackson, TN. There is also damage at Memphis International Airport. The local NWS was also evacuated of non-essential personnel.

Live weather stream below from Ustream.tv:

Sadly, I've seen a report on a storm chase blog of at least 2 fatalities at Atkins, AK.

Tremendous swath of Tornado Warnings are seen below on this radar image taken at 6:57PM EST:

Overnight Danger Zone tonight will probably be eastern AK, western-central KY and southern Indiana. This area may see tornadoes...possibly long lived twisters on the ground.. Our Severe WeatherCenter has live real-time coverage.

The threat shifts into the Eastern US on Wednesday...but will weaken overnight and on Wednesday. Thunderstorms may develop along a squall line Wednesday with a slight risk for isolated tornadoes but straight line winds posing a bigger threat. Check your local forecast and our Severe WeatherCenter overnight and on Wednesday.

Stay safe.

Everything From Ice to Thunderstorms!
Thursday, January 31

Very brief discussion as I'm on the road until this evening.

High Pressure is migrating as planned and will be over New England tomorrow. Southern storm coming up and will bring copious moisture into the Mid-Atlantic later tonight. East of VA Route 29/South of VA I-66 this looks to be a rain event...maybe some sleet pellets thrown in to remind us it is winter.

Cold wedge sets up from extreme NW NC mountains up through the New River, Roanoke and Shenandoah Valleys, along the Blue Ridge and into eastern WV. I'm not as sold as is the NWS on a prolonged ice event, but you'll certainly want to heed their advice on current Ice Storm Warnings and Winter Storm Watches. These areas will see more wintery weather and a high probability of "black ice" overnight and Friday morning before temps quickly surpass 32°. I-81 Corridor up into Western MD and central PA look like early target zone for icing before a change to rain.

Significant snow-ice-rain event as one traverses PA from west to east on Friday.

There is a possibility of strong to severe thunderstorms tomorrow for the Delmarva, eastern VA, eastern NC and the OBX! Strong storms, damaging straight line winds may also be accompanied by bow echoes and a very slight risk of an isolated tornado. More about this tonight so please check back this evening.

Have a great day!

UPDATE, 10:30PM: Surface map below is from 10:00PM tonight and nicely depicts current situation:

The dark blue lines are isobars (lines connecting points of equal pressure) and clearly show High Pressure we've discussed is located over New England. You can also easy see how those lines are forming a wedge from New Jersey down into Virginia and central-eastern North Carolina. While not "classic", this is a good visualization of Cold Air Damming (CAD). This is a chilly and dry air mass so it'll take time to moisten up but inland locations will be right at or very close to freezing when precip finally reaches the surface overnight.

You can also see precipitation moving up from the Southwest...that's associated with Low Pressure now moving up towards the Great Lakes. While all of it is not reaching the ground, when it does it will begin as freezing rain in areas outlined here previously: west of Route 29 and along/north of I-66 in Virginia. To the south and east of these locations, a touch of freezing rain and perhaps sleet, but mostly rain...heavy at times.

You can see how confidence builds for this forecast by looking at the current temperatures below (note: the above map is not current, but the temps below are):

The approaching storm is coming from the south and will pass to the west of the Mid-Atlantic States: Low Pressure spins counter clock-wise so this set up will push warmer air up from the south. The warmer air will come in above the cold air wedge (shown in the top map above) and therefore will fall as rain until reaching the colder air at the surface. That's why this will not be a snow storm for the Mid-Atlantic...but may be a significant ice storm along and west of the Blue Ridge where the coldest air will hang tough until well into Friday morning.

Tricky part remains how long will the cold air hold: the longer t takes to warm up at the surface, the more freezing rain will fall. Best bet for prolonged ice is the I-81 Corridor from Southern PA down to near Virginia Tech (Blacksburg). As this is written (10:45PM) temps in this portion of the I-81 Corridor are at or above freezing with low humidity and many single digit dew points. The wet bulb at our wx station in Lexington, VA currently is 28° and it is challenging to forecast how low the actual surface temps will drop overnight before heavy rain pulls down warmer air and temps begin climbing. This prompts the Ice Storm Warnings and Winter Storm watches along and near the Blue Ridge Mountains. I'm still thinking many risk area temps across the Mid-Atlantic States will get above freezing by mid/late morning and precipitation then evolves to all rain. But travel will be perilous overnight and early Friday in those areas getting freezing rain!

Piedmont and eastern NC and VA will be, as mentioned, mostly or all rain. Temperatures by Friday afternoon should be well above 32° across the region. Liquid precipitation totals may approach and even exceed one inch for much of the area.

The one caveat I always mention with this type of storm is watching Radar along the north-central Gulf Coast. Many, many times, a line of strong convective storms develop here and essentially "steal" moisture from the Mid-Atlantic area. This could again occur Friday and if it does, precipitation totals will be below what are currently forecast. So, keep an eye on your local conditions and check Radar along the Gulf Coast.

There remains a risk of severe weather in the Mid-Atlantic...specifically east of the I-95 Corridor from the Delmarva to Myrtle Beach, SC. Persons in this area should monitor our Severe WeatherCenter for real-time information on Friday afternoon.

Wednesday Night Thoughts on Thursday-Friday Storm System.
Wednesday, January 30

I thought the wintry mixed precipitation event advertised here last Sunday was right on track...until tonight! The 0Z models are getting jumpy about the storm and what type of precipitation will arrive Thursday night.

High Pressure is building in behind today's very windy Cold Front; this High will migrate up over New England and the Gulf of Maine, setting up an on-shore East wind for the region. *Nothing* good ever blows in on easterly winds and colder air has been forecast to set up a Cold Air Damming (CAD) event. Meanwhile, Low Pressure currently over west Texas tracks toward NOLA before heading up into the Great Lakes. Moisture from this system overspreads the region on Thursday night and with cold air coming in around the High, we should have a sleet event over western NC...with a touch of freezing rain mixing in with plain rain for the Piedmont. Virginia locations east of the Route 29 corridor would have a very cold rain with temps just above freezing. West of Rt. 29, precipitation has been forecast to be in the form of freezing rain and thus the Winter Storm Watches and Warnings.

Tonight's runs of the Nam and the GFS models now push the Low a bit further northwest up into the Lakes. This delays the onset of precipitation...possible until Friday morning at which time temps would be climbing above the 32° mark for all but western and elevated locations. If this pans out we'll see mostly rain in Virginia except along and west of the Blue Ridge where there should be some sleet and a little freezing rain.

Lower Lakes probably takes a thumpin' from this storm...especially from Central IL through Western NYS. PA and the Southern Tier of NY may end up with a significant sleet storm.

We'll need to take another look at this in the morning but for now there are signs just enough warm air comes up to produce more rain over a larger area of the Mid-Atlantic. As always, check your local forecast here at Mid-Atlantic WX.com and visit our Winter StormCenter for real-time information.

Next update here at the blog by Noon on Thursday. Have a good night.

Another Change At The Top of NHC...And...
Some Warmer Weather Awaits, Then Wintry Mix and Rain.
Sunday, January 27

Brief discussion as I am flying to Atlanta today to attend a short conference. Fortunately, the weather here in the Mid-Atlantic region will be rather tranquil while I'm away.

More news out of the National Hurricane Center as Bill Read has been appointed the new director. Read comes from the NWS Office in Houston, TX and more recently has served as NHC's acting deputy director since last August. NHC's press release is here.

Weather-wise...Low Pressure organizes off the Mid-Atlantic coast and heads Northeast as High Pressure deep in the heart of Dixie moves East. This High will bring warmer air from the south up over the Mid-Atlantic region into the middle part of the week...before the next Cold Front approaches late Tuesday with a high probability of rain late Tuesday into Wednesday. High Pressure builds back into the area behind this front with another Cold Air Damming (CAD) event setting up on Thursday. Another storm heads up towards the East and wintry precip is possible inland and for the higher terrain...freezing rain north of the VA I-64 corridor. As this second storm is coming up from the south, warmer air will over run the CAD and should scour out cooler air, making for a significant rain event into Friday. We'll need to tune up the timing and precipitation types with another update to the blog on Wednesday evening...so please check back then.

Little warmer early this week...enjoy! :)
.

Winter Weather Again Approaching on Tuesday...and...
The Cold Will Hold Till The Weekend.
Monday, January 21

The savage Ridge of High Pressure is now sliding off shore and with it just one more night of brutal cold.

This is a very strong Ridge as evidenced by a peak reading of 30.76 inches this morning at our weather station in Lexington, VA. Current barometric trend (click graphic for our weather station):

Current US Surface Map shows High Pressure right over the Mid-Atlantic while Low Pressure is noted over the Central Plains...this is our next weather-maker coming on Tuesday. This system will be over the Lower Lakes on Tuesday with the attendant Cold Front reaching the Gulf Coast, Southeast and Mid-Atlantic States by afternoon. The atmosphere should be relatively stable but thunderstorms could fire up Tuesday from LA to SC.
Different story from NW SC into PA...generally along the mountains and the I-81 Corridor...as cold air will hold and wintery precipitation is expected. Light snow and freezing rain will overspread this area in the morning before a change to rain and drizzle by afternoon (except along and west of the Alleghenies where snow will continue during the day). Snow totals will be modest: less than 1.5 inches and freezing rain won't accumulate but will produce some glazing and "black ice"; therefore extreme care is needed for the morning commute. Temps for most of the area will exceed 32° by late morning...before dropping again tomorrow night when snow may again fall over the mountains and highlands.

This setup is very conducive for Lake Effect Snow (LES) and several inches should pile-up in typical locations into early Wednesday morning.

Next precipitation comes in early Thursday with an Alberta Clipper bringing in a little moisture that may produce light snow early Thursday. A final infusion of cold air follows the Clipper with temps much below normal back in the forecast. Another system approaches next weekend, probably arriving on Sunday...but this should be a rain event.

Temperatures will remain very cold into Friday at which time we'll see a rebound to near and normal temps into the weekend and early next week. I noticed today's 12Z of the GFS sets up a High Pressure Ridge off the SE US coast next week which if true, would warm up the region beginning the 28th. We'll see!

Off Topic: How I Spent My Weekend: As mentioned in the last blog, I went camping with the Boy Scouts this weekend in the mountains of Virginia. Mighty cold! Saturday's high was 35°, the overnight low was 10° and it was 17° on Sunday morning. The purpose of the weekend camporee was to teach boys winter skills and how to have fun outdoors in the cold. One such challenge is to start a small fire using 2 matches and one wet piece of wood. I took a picture of this activity (click thumbnail below to enlarge):

In the foreground you see a tub filled with cedar logs floating in warm water. Teams of Scouts were told to take one cedar log and two matches. In the background a couple teams working on this challenge are visible: their objective being to make a small fire that burns a suspended string 18 inches above the ground. Accelerants were prohibited but the Scouts were permitted to use anything else they could carry (dryer lint is a favorite). Those who came prepared had pocket knives and a camp hatchet while others carried twigs in a zip-lock bag. They were given 15 minutes to accomplish the challenge. Of the 24 patrols attending, 17 met the challenge. Over 120 local boys attended the event and all learned leadership, winter survival and team building skills. These are the guys who are the leaders of tomorrow and that's why I am so optimistic about the future. But...it could have been a few degrees warmer!

Next scheduled update here at the blog on Sunday (prior to a trip to Atlanta)...sooner if conditions warrant.

Saturday Storm Solely in the South...While ALL Aboard the Arctic Express!
Friday, January 18

Time to prepare for The Next Big Thing...the second storm to affect part of the Mid-Atlantic States in three days.

Low Pressure over the western Gulf of Mexico moves east today and gets organized south of the Florida Panhandle tomorrow...before tracking off the SE US coast tomorrow night along a frontal boundary now draped over the GOM and Florida. Model map below shows anticipated track forecast from the GFS and NAM models (click graphic for more maps and models)

Radar now shows some mixed precip SW of Dallas/Ft. Worth as the system moves east...producing rain along the north-central Gulf States later today. Cold air now in place will allow for some snow/mixed precip along the northern edge of precipitation; likely to be northern counties of MS, AL and GA (more snow for northern suburbs of Atlanta!). As the Low tracks off shore, a stripe of snow should develop from extreme NW GA along a line to SE VA. Right now, the heaviest band of snow looks to be roughly from Asheville/Spartanburg, NC to Raleigh/Durham, NC and over to Emporia, VA. If this pans out, this area may see totals exceeding 4 inches by Saturday. This is going to be a pesky storm (no...I'm not a Red Sox fan!) in that the distance between accumulating snow and nothing will be very narrow...so this is merely a preliminary guess on snow totals. I am skeptical we'll see more than a dusting to one inch north of VA I-64. As always, check your local forecast and visit our Winter StormCenter for real-time information.

Northward progress of this storm isn't an option due in part to the approaching Mother of All Cold Fronts on Saturday. Brutal Arctic High Pressure (1035mb) now over Alberta will dive into the Nation's Heartland and will push a frontal boundary into the Eastern US on Saturday. Behind the front, air of arctic origin will produce the coldest temperatures of the season through Tuesday. This pipe-bursting Ridge will migrate over the Mid-Atlantic States before sliding off shore midweek...setting up a weak return flow with temps closer to normal.

I don't see a prolonged warm-up coming, but rather, an active sequence of storms with cold air holding over the next 10 days.

Current PNA analysis:

Current AO Ensemble forecast:

I'm oversimplifying things, but as a rule, a +PNA and a -AO signal cold and stormy in the Eastern US. The opposite is often observed: recall the weather in early January...warmer than normal and dry in the East. Note at that time the PNA was negative and the AO was negative but rising. A +PNA coupled with a -AO will accompany High Pressure in the West and a trof in the East. Again, I'm painting with a very broad brush and there are several other factors but these indicators teleconnect with future weather trends. If you'd like to see these charts or learn more about them please visit our Winter StormCenter and scroll to the "Forecast Graphs & Charts" drop-down box.

Next update will be on Sunday as I am going to a winter camporee with the Boy Scouts this weekend. Forecast low temperature at the camp on Saturday night is 8 degrees! I'll return to the blog on Sunday after thawing out my hands!

Stay warm and have a good weekend!

Let it (Mostly) Snow, Let it Snow, Let it Snow!
Thursday, January 17

Low Pressure now tracking from Florida Big Bend will be over OBX/VA-NC border tonight. High Pressure over the Northeast slides east as the Low heads up the coast tonight and tomorrow. Last night's tune-up on the forecast looks good with generally a snow event from west-central NC, VA, MD and Metro Washington DC. Richmond again right on the line with a mixed bag of mostly liquid precip along the I-95 Corridor with coastal location above freezing with rain. Current temps from our exclusive Mesonet Map:

This map also shows the CAD event we've discussed...cold air at the surface is prevalent along and east of the mountains into the Piedmont. Thinking is VA locations west of Route 29 probably are all snow or snow to a brief period of freezing rain/drizzle. Snow totals should be in the 3 to 6 inch range...more possible over higher ridges. East of Route 29, temps ebb up to and a little over the freezing mark this afternoon with a change to some freezing rain/drizzle. Along and east of the I-95 Corridor (including the Delmarva), temps are above freezing with rain being the main p-type.

Forecast looks good to the Northeast with snow roughly from Scranton, PA into "The County" in Maine. Heaviest accumulations from the Berkshires to Bangor.

9:30AM this morning: 2 inches outside the Mid-Atlantic WX.com office in Lexington, VA:

I'll have another update this evening so please stop by here at the blog.

UPDATE 11:35PM: Precipitation has pulled away from the Mid-Atlantic as the Low moves toward New England. 4.75 inches recorded at our wx station in Lexington, VA. Snowfall amounts generally in line with earlier forecasts: winner looks to be Swoope, VA in Augusta County where 8 inches has been reported. Interestingly, I am camping this weekend at a Boy Scout Camp in Swoope...figures!

Attention quickly turns to the next system to impact the region late Saturday. I'll have a quick update tomorrow morning by 10AM.

"GO" for Snow Before Brutal Cold Comes Calling From Canada!
Wednesday, January 16

Low Pressure over the GOM is currently (10:30PM) south of the AL/MS line and will track up into the Coastal Carolinas on Thursday. Chilly air mass in place...it snowed in Atlanta today...and precipitation shield now moving from Gulf/Southeast US into the region. Very dry air at the surface will take time to moisten up and so precip may hold off north of I-85 until early Thursday morning. For a snap shop of conditions, check our exclusive wet bulb located in Lexington, VA...click here to visit our weather station.

Both the 18Z and the 0Z NAM showed more precip and a return to colder air after a very slight overnight warm-up...this would produce more snow and less freezing rain over western and central NC as well as much of VA west of I-95. That Cold Air Damming (CAD) scenario outlined in yesterday's discussion also looks good, so this may be mostly snow along and west of the I-95 Corridor. In fact, tonight's soundings are *colder* than what the 18Z models depicted, bolstering confidence there will be more snow and less ice. So, accumulation totals will be tricky in areas warmer air moves in just above the CAD. We also need to see if the anticipated "dry slot" comes through and curtails precipitation totals. Lots of variables here!

Unless you are east of I-95 this should be a mostly snow event. Is this the storm that finally puts snow in Richmond? I think so! Widespread 3-5 inch totals likely from west-central NC through the Piedmont and interior Mid-Atlantic, central MD and then into New England. Please visit our Winter StormCenter for updated watches and warnings.

Well advertised brutal cold makes it into the East on Saturday...just in time for another storm to zip through. Check your local forecast for snow potential on Saturday and Sunday.

For a quick update and status report on this event please check here at the blog on Thursday morning after 10AM.

Mixed Mess for Mid-Atlantic Before The Icebox Opens!
Tuesday, January 15

As is often the case for the Mid-Atlantic, here's the typical storm genesis:
Forecast 1: snow, except the coast.
Forecast 2: snow changing to freezing rain.
Forecast 3: quick burst of snow then freezing rain, followed by rain.
Forecast 4: freezing rain, then rain.
Forecast 5: rain.

I'm exaggerating, but only a little! While the Thursday-Friday event has never been advertised here at the blog as a Mid-Atlantic snowstorm, we are seeing "warm creep" into the models...very common 2 days before a storm.

Current setup calls for High Pressure to build in from the west over the Mid-Atlantic States while Low Pressure gets going over the Gulf and heads up the coast off the OBX on Thursday evening. High Pressure will keep temps cold enough for precip to begin as snow from the mountains of GA/TN/SC/NC up into Virginia west of
I-95. Timing looks like early Thursday morning from the interior SE, morning commute Charlotte to Roanoke-Lynchburg...then overspreading areas to the north by early Thursday afternoon. Mountains and western highlands could be in the 2-3 inch range before warm air noses in just above the surface causing a change to sleet or freezing rain. Differing precipitation types based on elevation and how shallow the warmer layer will be as it moves into the region.

Near and east of the I-95 Corridor this should be rain with a slight risk of freezing rain pockets north of Petersburg-Richmond.

Another tricky feature is as the High slides off there could be a cold layer right at the surface...similar to a classic Cold Air Damming (CAD) event. This is when colder air is blown inland on east winds and stacks up (dammed) along the eastern slopes of the mountains. This very shallow surface layer is colder than the air just above it and can change the precipitation type with very slight changes of elevation. So, we need to see how this will develop. Most interior Mid-Atlantic areas will see snow changing to freezing rain while Piedmont and areas east of I-95 will generally be rain.

The Low tracks just enough to the west to keep warmer air along the coast so this should be a rain event up and east of I-95, perhaps as far north as Portsmouth, NH. Inland New England should be all snow with several inches possible.

Behind the departing storm, the Polar (Northern) Jet dives deeply into the eastern US with a fresh supply of very cold air. Saturday night temps should be the coldest of the season with very cold highs on Sunday and Monday as the Arctic High will be directly overhead.

Active sequence will continue with Gulf moisture poised to head into the region Saturday night and another system taking aim on the Southeast and Mid-Atlantic region on Tuesday. By then, the High should be moving off shore and that will allow some moderation in temperatures by mid-next week.

Several snow bands made it over the Alleghanies this morning; here's how it looked at 8:45AM today at Virginia Tech in Blacksburg, VA:

Incidentally, the new Virginia Tech April 16 Memorial is in the foreground. If you care to read more about this tribute, please click here to visit the Virginia Tech site.

I am on the road tomorrow but will try for a brief tune-up update late Wednesday evening. Please check back then!

Wimpy Weekend...Midweek Maybe.
Sunday, January 13

Quick update to be followed by more discussion this evening. Nil on white stuff today for Mid-Atlantic however as the trof swings through there will be showers/light rain and possibly some mixed snow over the western mountains. Coastal Low still on track to organize tonight before pulling away and threatening the Northeast on Monday.

Models (GFS in particular) still on board with potential winter event Thursday-Friday and tonight's discussion will see how we look with the 0Z model runs. For now, the possibility of winter weather remains on the table for later this week.

Time to catch some football. Please stop by this evening for an update here at the blog.

UPDATE 11:00PM: No changes with tonight's 0Z models in coming together on late Wednesday-Thursday winter event. Low Pressure will form near the TX Gulf coast and move toward Big Bend and then the Georgia coast before heading up the coast. Snow could mix with sleet for northern AL, MS and into NW GA late Wednesday. This set up is favorable for snow over interior SE as well as interior NC and VA before the Low warms temps nearer the coast on Thursday afternoon. Should this pan out, accumulating snow inland with a changeover to mixed precip is possible Thursday. Still early to pin it down but we can expect winter weather from the northern Gulf Coast states into the TN Valley, WV and Mid-Atlantic. I'll update the blog on Tuesday and invite you to stay close to our Winter StormCenter.

The Cold Will Take Hold...And...
VERY Active Pattern Will Bring the Storm Train East, For 2 Weeks...At Least!
Saturday, January 12

A multiplicity of storms loom on the horizon as we undergo a significant pattern change that will put an end to the temperature roller coaster in the Eastern US. Polar Vortex is migrating, Northern (Polar) Jet Stream will buckle south and cold High Pressure builds in: yep, the pattern is changing.

Low Pressure will develop over Texas and migrate across the Gulf of Mexico this weekend. Looks like a somewhat negatively tilted trof (good if you like storms) forms as the Low gets pulled together near the Carolinas coast; this is depicted by the GFS and the NAM on the model map below (click image for more graphics):

I don't believe this storm is much of a winter weather maker for the Lower Mid-Atlantic with coastal rains being the main feature. Can't rule out a wet snow/rain mix along and west of the Blue Ridge Sunday morning, or a slight chance for a wet snow mix over the Piedmont, but temps will exceed 32° during the day on Sunday, so I'm not enthusiastic about accumulation.

The storm departs the Mid-Atlantic coast on Sunday night and as is often the case, strong winds will blow behind the storm along with some upslope "back lash" snow for the mountains. A quick glance at the model map above screams one word: "Nor'easter"! Track and timing look good for a widespread snow event from the Poconos through northern New England into Monday night. Thinking right now is 4+ inches of snow east of the I-81 corridor, north of the Potomac River. Philly will likely see slushy wet snow and I think NYC has a genuine opportunity for 3-5 inches of white stuff! Worcester, MA into interior Maine could see the Mother lode of 12+ inches when all is said and done. Check our Winter StormCenter for real-time info and keep an eye on your local forecast right here at Mid-Atlantic WX.com.

I'll update the blog on Sunday morning, so please check back for the latest on this storm.

Cold High Pressure keeps temps at or below normal into Wednesday at which time the Ridge will slide off the coast and bump up temperatures for the Mid-Atlantic and Ohio Valley areas. This is when a new Low will form over the Gulf and head up the East Coast. This system will bring rain to the north-central Gulf Coast and Southeastern US States and may pose a winter threat for the Tennessee Valley and interior Mid-Atlantic on Thursday. As always, strength and track are to be determined but a snow/freezing rain to rain scenario is possible from the NC Piedmont into Virginia and the DC-Baltimore Metro on Thursday. This system will be monitored with updates next week here at the blog.

A third storm is hinted in long range model for next weekend for much of the East Coast, showing we are in an active pattern and one that I believe will hold through the balance of January.

Cool Cold Front: On Friday, a weak Warm Front was moving up across the Mid-Atlantic while a Cold Front tracked east as Low Pressure spun over the Great Lakes. You can see these features on the morning surface map for Friday, January 11:

Frontal boundaries frequently show up on satellite and that was the case on Friday morning:

What appears to be a line from Buffalo, NY south into central NC is the advancing Cold Front pushing up clouds along the boundary. To the east of the line, low clouds and fog are apparent in the warm sector.

This classified as a Cold Front that was "very cool"!

Please check back here at the blog during the week as I'll have updates on the upcoming active sequence of storms.

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