Looking more wintry

In the midst of a nearly snowless winter, we now have two shots at accumulating snowfall over the next 96 hours.  In the meantime, get ready for a biting wind this afternoon as a much colder air mass enters the region.  We’ve already seen wind gusts over 40mph in some areas, and this will continue as temperatures tumble to near freezing by dusk! 

The wind will calm down significantly overnight, and with clear skies, temperatures will plummet into the 20s in the city and teens in the suburbs.  We’ll start the day tomorrow with bright sunshine, but clouds will gradually increase and there could even be a few snowflakes by dark near the Delaware Water Gap.  This is in response to a small, but energetic area of vorticity (aka “spin”) in the upper atmosphere moving from west to east across Pennsylvania and New York.  There’s almost always rising air ahead of these systems, and if there’s enough moisture, rising air will cause precipitation.

In this case, there will be just enough moisture for snowfall to break out tomorrow night.  We’re not expecting anything heavy, but a coating to an inch is a possibility.  In fact, based on probability analysis from the SREF models, there’s a good bet (>50%) of receiving at least an inch of snow by Friday morning over Sullivan and western Ulster Counties.  That probability falls to about 30% along I-84 from Orange through Putnam counties.  Snowfall should be limited to a coating for the New York City area.

These are 12 hour snowfall probabilities ending at 7am Friday based on the SREF.  The maps can be found on Penn State’s ewall site.

After a bright but cold Friday, our next system will arrive on Saturday morning with snow to start.  This should change to rain for much of the area by the time it’s all said and done Saturday evening.  The distribution of snowfall amounts may look very similar to tomorrow night’s system, with the best chance of an inch or two being well north and west of the city.  We’ll have many more details on that as the event gets closer!  Until then, stay warm!