Wild Weather Tonight and Sunday

Good afternoon my friends. A rare late season Arctic outbreak will lead to some wild weather in Southern New England.  Vicious snowsqualls with winds gusting as high as 60-70 mph are likely as an Arctic clippers explodes offshore tonight.  Thundersnow is likely and this can lead to 2-4" of snow in a short timeframe.  Let's break this down

General overview
Eastern MA including Southern Worcester county and NE CT and RI are under a high wind watch. Southern CT has a high wind warning while the rest of the region is under a wind advisory

http://www.weather.gov/wwamap/wwatxtget.php?cwa=box&wwa=all

Here is the clippers as of 11 am.  This morning's rain was a result of low pressure riding along the cold front offshore.  Temperatures will warm to the low 50s as another boundary swings through early this evening. 

WPC surface analysis 11 am

The clipper is in the Great lakes region.  As the boundary in western New York moves through New England this evening thunderstorms with hail and gusty winds will accompany it.  At the upper levels we see an energetic atmosphere primed for mischief.  Here is the mid level of the atmosphere

12z NAM 500 mbps vortex valid 2 am (image NCEP)

Forecast

Now let's take a look at some radar simulations.  First is 8 PM tonight.  A line of showers and thunderstorms will progress across Western New England and arrive in Worcester County between 7-8 PM.

17z HRRR STIMULATED RADAR (image weatherbell)

These storms will drop small hail.  The precipitation will return around 1-2 AM.  This is when the clipper will be approaching the Southern New England waters. The storm will rapidly intensify.  Here is the 3 am simulated radar.

17z HRRR Simulated radar 3 am (image weatherbell)

Winds will be able to gust 45-65 mph at this time.  That is easily enough to knock down trees and powerlines.  Snow totals will be generally light but in the heavy thundersnow bands up to 4" may fall. Snow ends around 9-10 am.  This is enough for a winter weather advisory

NWS boston watches and warnings

Peak winds are around 5-11 am.  This is a aanomalous weather pattern so there could be a surprise or two. Another clipper is on the way for Monday.  I'll have more on that tomorrow. By the way it will be cold over the next few days. Bundle up!

 

-Zack Green