Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
403 PM EDT Sat Oct 20 2018
Valid 00Z Sun Oct 21 2018 - 00Z Wed Oct 24 2018
Days 1 through 3...
...Central Appalachians (Day 1)...
A potent shortwave rounding the trough base across the Great Lakes
this afternoon and evening will cross the central Appalachians
later tonight. Robust QG forcing this evening (DPVA ahead of the
trough) will lead to mostly rain given the low-level warm layer
ahead of the front, though on the backside of the upper
trough/surface front the increased low-level CAA will help
maintain lake-enhanced bands of rain and snow showers, with the
activity then getting somewhat of a boost orographically by the
time it reaches the central Appalachians given the northwesterly
Probabilities for 4 or more inches of snow during the day 1 period
were highest (20-30%) in parts of northeast WV from Elkins to
Canaan Valley south toward Cheat Mountain and Valley Head --
particularly in elevations aoa 4,000 ft.
The probability of significant icing (0.25 inches or more) is less
than 10 percent all three days.