Get the Sleds Ready… High Ratio Snowfall Headed for Washington!

dcstorms-com_snowfall_accumulation_07jan17

Winter Weather Advisories were issued for Fairfax, Arlington, Prince William counties.  I will not be surprised to see these expanded further north and west tonight.  This storm is going to cripple central Virginia, the northern neck of Virginia, southern Maryland, the eastern shore of Maryland and coastal New Jersey.

My confidence has increased that a solid 2 to 4″ will fall across the immediate Washington Area with our outer southern and eastern suburbs possibly winding up with 4 to as much as 8″!

This storm will be a fast mover, but the arctic air is in place. Every flake will stick causing treacherous travel late tonight into Saturday.

The models keep slowing this down a bit so don’t be surprised if start and end times are extended a bit.

What do I mean by high ratio snow? With snow coming down with temperatures falling into the lower to middle 20s… ratios could be as high as 1:18! It will not take much moisture to produce accumulation.  This will be a dry snow, not good for making snow balls but great for sledding! 

Latest Forecast Models:

First up is the 1:15 ratio European (my favorite model and the one I trust the most):

ecmwf_tsnow_15_maryland_29

The North American Model showing 1:10 ratios (hence the algorithm being used in this particular model should be using higher ratios of 1:15):

hires_snow_washdc_61

Blizzard Warnings were just issued for the Tidewater and Virginia beach.  Don’t be surprised if those are extended up the coast.

All you need to have Blizzard Criteria are winds in excess of 35 mph and visibility of less than a 1/4 mile for more than 3 hours (has nothing to do with how much snow is on the ground).  I think this criteria may be met along the Maryland and Delaware beaches, eastern Long Island and Cape Cod, especially if overnight the short-range models inch the storm a bit closer to the coast and deepen it more rapidly over the very warm Gulf Stream waters.

Here is the 1:15 European snowfall forecast for Central Virginia:

  • Potential for historic snowfall totals from Raleigh northeastward to the Tidewater! Yes, it is possible that some locations could pick up a foot and a half of snow!

ecmwf_tsnow_15_norfolk_18

Philadelphia:

ecmwf_tsnow_15_philadelphia_18

New York City:

  • Look out in eastern Long Island with  Montauk getting raked with easily a foot of snow.

ecmwf_tsnow_15_nyc_18

Boston:

  • Those of you on Cape Cod… this storm means business!

ecmwf_tsnow_15_boston_18

Temperatures under clear skies and calm winds in the storm’s wake on Monday morning will likely plummet below zero under snow-pack with prime conditions for radiation cooling!

ecmwf_t2min_virginia_13 ecmwf_t2min_neng_13

2 Replies to “Get the Sleds Ready… High Ratio Snowfall Headed for Washington!”

  1. Maybe for once, some of the common sense old fashioned synoptics, like a phased in negative tilt trough will win out!

    My other wishcast is that sometimes very heavy snowfalls take place very close to the cutoff line between snow, and no snow, and a bit further north of where the models show. A classic example of that was last January when Harrisburg and NYC had record snowfalls (close to 30″) when they were very close to the snow cutoff line. How many times have the models predicted the heaviest snow from DC south, when Damascus received the most snow?

    It should be fun to follow this.

    Like

  2. Looks like even areas that get light snow may get a few inches were’cluding Loudoun where I live). I can’t wait.

    Like

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