Major Snowstorm for the Mid-Atlantic unfolding this week

After spending majority of the winter snow free and unusually warm, the last week of the season is delivering with a solid punch.  Arctic air has been in place this weekend and snow is likely by Monday night.  It’s not the first time we’ve had to deal with a snowstorm in March.  March of 1993, 1999, 2014 and 2015 all brought snowfall just before the official start of spring; history will likely repeat itself this year. 

Confidence has grown that a significant winter storm will impact the DC area with heavy, wet snow beginning Monday night and lasting through Tuesday morning.  A Winter Storm Watch has been issued for most of the region:

 

Counties south and east of DC are not included in this watch due to the fact that too much mixing and/or rain will greatly limit snow totals.  This watch will either be upgraded to Winter Storm Warnings or changed to Winter Weather Advisories by Sunday evening.  Here are the latest thoughts on storm timing:

 

                Majority of the accumulating snow will fall between 12am-6am Tuesday morning.  Widespread cancellations and delays can be expected for Tuesday.  This will be a heavy, wet snow that could cause roads to be impassable and power outages to occur.  There will likely be a very sharp gradient of snow totals across our area due to the fact that the rain/snow line is expected to set up just south and east of DC.  Any variance in this line of demarcation will cause dramatic swings in snow totals.  Here is our first call on localized snow amounts: