Update on Weekend Winter Storm

You may have heard about a winter storm potentially impacting Southern New England this weekend.  A plowable snowfall is likely for many.  Here's a breakdown with my thoughts.

The Big Picture
A series of Arctic fronts will push through the New England tonight and Friday.  This will keep temperatures in the teens and low 20's tomorrow.  The sun will be shining but that will just be for show.  Here is the current surface chart

WPC Surfce Analysis 4 PM EST

The main driver of the weekend storm is not even onshore yet in the Western US.  It will enter in Southern CA and track into Texas.  Once there the storm will split and one low center will decay as it moves up into Wisconsin.  Another low will try to run inland but high pressure to the north will force the low to reform off the New England coast.   Here is Saturday morning at 7 am

WPC Surface Forecast Saturday 7 am

Here are the 850 mb temps (5000 feet) Sunday 1 am

12z EURO 850 mb temps Sunday 1 am (image weatherbell)

These are plenty cold enough to support snow for all of New England through Sunday AM.  By 7 am some warm air will work in off the Atlantic changing the precipitation to sleet, freezing rain, and in some cases plain rain.  Here is the Sunday AM surface forecast

WPC Surface Forecast 7 am 

Timing & Impacts

Warm southern air will be running into a cold arctic high.  When this happens precipitation tends to break out hours before the storm is close.  I am seeing some signs that light snow could break out Saturday morning.  Steady accumulations begin after 7 PM Saturday night and will last into Sunday morning.  Don't believe the storm will be strong; but the dynamics are impressive.  Here is my current thinking

Saturday-Sunday storm outlook

Meanwhile bundle yourselves up tonight.  Lows drop down to around 10 tonight

22z HRRR 2 m temp 7 am (image weatherbell)

I'll have more as confidence increases.  Right now I'm curious as to how much snow will fall during the day Saturday.  This is NOT a repeat of February.  But it could be a decent December storm.  

-Zack Green