Scott's Mar 2008

Mid-Atlantic Radar

Scott's March, 2008 Blog
(blog descends chronologically)

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.

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