The storm, that will turn into a behemoth over the Atlantic ocean, is likely to bring some snow to the region during the day Tuesday, perhaps lasting into the evening in eastern areas. For most of  the region the snow is a nuisance rather than disruptive, mainly accumulating on grassy areas.


  • Generally, around 1 inch on grassy areas is the most likely amount.  The best bet for 1-3 inch amounts are in the mountains where it will be coldest, and perhaps towards eastern Delaware – closest to the storm center.
  • The two time windows when there could be a little slush build-up on roads are: 1) early Tuesday morning – when temperatures will still be near/below freezing – if the snow starts early enough, 2) Tuesday evening in far eastern areas as temperatures fall back towards freezing.  As usual, the best chance of accumulation on roads is in our colder north and west suburbs.  But even there, we’re not talking about highly disruptive/hazardous conditions – rather the possibility of a bit of slush build-up/slick conditions mainly on side roads.
  • The fact that the majority of the snow in the D.C. area is forecast to occur late morning to mid-afternoon will minimize accumulation on roads most of the day due to temperatures rising above freezing and the high late March sun angle


CWG snow amount forecast, Tuesday, March 25. Issued 2:30 p.m. Monday.


  • 4- 8 a.m.: 30 percent chance of snow developing.  Temperatures 28-32.
  • 8 a.m. to noon: Snow likely developing (70 percent).  Temperatures rising from near freezing to 33-36.
  • Noon to 4 p.m.: Snow decreasing in coverage after 2 p.m., focusing more towards the eastern shore.  Temperatures 34-38.
  • 4 to 10 p.m.: Scattered snow showers and flurries possible (40-60 percent chance west to east) – best chance east of the District – as the ocean storm starts to develop possibly producing wrap-around snow bands. Temperatures 32-36.


1 apple: Do your homework.  Snow likely starts too late (after 4-5 a.m.) to impact school decisions and is not expected to amount to enough for schools to delay/close preemptively.


1 dome: Expect to report to work on time.

What about the wind?

As the ocean storm rapidly intensifies Tuesday night, winds will start to crank.  By very early Wednesday morning, winds will become sustained at around 20 mph, perhaps 25-30 mph towards the eastern shore, with gusts in the 30-40 mph range (isolated gusts of 40-50 mph near the Bay and points east).

High resolution NAM model forecast of wind speeds at 11 a.m. Wednesday (