Very impressive plume of moisture moving northward out of the Carolinas as colder air is becoming entrenched across the Metropolitan Area. High Resolution Models becoming very bullish on much heavier snowfall totals inching closer to the Capital Beltway.
This storm is now in “now-cast” mode… as ingredients are coming together for a high-impact dangerous Winter Storm across the immediate Washington & Baltimore Metropolitan Areas.
** This may be one of our areas biggest March Snowfalls north and west of the Beltway**
DCstorms.com is now predicting a 70 to 80% chance of Federal Offices closing based upon the latest HRRR data. Temperatures in DC are now forecast to drop into the upper 20s!
After pulling my hair out and enjoying a glass of red wine (while stewing over the latest High-Resolution-Rapid Refresh Models and the 18z GFS) below is my updated & final snow and sleet accumulation map for the blockbuster Nor’easter that will be impacting the Northeastern seaboard tonight through 2pm Tuesday:
This is one of the trickiest forecasts I can remember for a “large storm” in the over 20 years I have lived in this Area. This storm has the potential to surprise between route 15 in Loudoun county and just west of the interstate 95 corridor where confidence is very low.
High impact Nor’easter still slated to slam the Washington Metropolitan Area this evening through Tuesday. Thunder-Snow and sleet is possible overnight with gusty winds (40 mph +) and snowfall/sleet rates of one to two inches per hour during the overnight hours!
The exact snow/snow-sleet/sleet-rain line is still in question but it is important to remember that where this line sets up, one won’t have to travel too far to go from lighter accumulations to significant accumulations.This is why it is prudent to be prepared for this major high-impact winter storm (the potential loss of power) than to focus too much on any slight shifts back and forth between where this line sets up. Please continue to monitor the official forecast from the National Weather Service as those of you under Winter Weather Advisories could still be upgraded to a Winter Storm Warning later today.
As of 5AM No changes to my snowfall map:
After looking at the all-important European Model I am sticking with this for now. Any update to this map won’t be made until this afternoon.
The area of highest uncertainty in my opinion continues to be those of you located in the “4 to 8” and “1 to 4” zone in the map below.I can see a situation where this zone gets shrunk very close together meaning the short west to east distance from Woodbridge, VA to Waldorf, MD could see a snowfall gradient of 10″ or more!