Mid-Atlantic WX.com 48 Hr Forecast Map

In addition to High and Low centers, you may see one or more of these seven features on a surface Analysis or Forecast:

Key to Features
1 -- Cold Front
2 -- Warm Front
3 -- Stationary Front
4 -- Occluded Front
5 -- Trough ("TROF")-- Also used to depict:
Outflow Boundary ("OUTFLOW BNDRY")
Tropical Wave ("TRPCL WAVE")
6 -- Squall Line
7 -- Dry Line

Each surface front and squall line (1, 2, 3, 4, 6 above) is accompanied by a 3-digit label that has a bracket either before or after it. Using the example "[ABC", here is how to translate the label:

A: Type of Front
    0 = stationary
    2 = warm
    4 = cold
    6 = occluded
    7 = squall line

B: Strength of Front
    0 = none (applies only to squall line)
    1 = weak, weakening
    2 = weak
    3 = weak, strengthening
    4 = moderate, weakening
    5 = moderate
    6 = moderate, strengthening
    7 = strong, weakening
    8 = strong
    9 = strong, strengthening

C: Other Characteristics
    0 = none
    5 = forming
    6 = quasi-stationary
    7 = with waves
    8 = diffuse