Snow, Ice, Rain and a Brief Warm Up

A weak low pressure system will approach from the SW on Saturday and bring with it a variety of precipitation.  Though we are all sick of it snow is the preferred outcome.  However with a storm track to our west warmer air will work into New England changing the initial snow burst to ice and rain.  The details...

NWS Boston Advisories 

Region wide (sans CC) a winter weather advisory is effect from 1 pm tomorrow through 1 pm Sunday.  Everyone starts as snow early tomorrow afternoon.

Here is the current surface chart.  Notice the front in the southern plains pushing towards high pressure in the east

WPC surface analysis 4 PM

For visual learners here are the 5 PM US temperatures

US 2 m temperatures 5 pm (image Weatherbell)

Here is the water vapor satellite loop

GOES WATER VAPOR LOOP (IMAGE NOAA)

Before we get to any storm there is a very cold night ahead. Here is one high resolution weather models take for minimum temperature through 8 am

22z HRRR min 2 m temp (Image Weatherbell)

The storm will want to warm Southern New England.  But since cold air is more dense than warm air the warmer air will be forced up over the cold and so everyone starts as snow

Overrunning event diagram via Boston.com

Here is the surface around 1 pm

WPC surface forecast 1 pm Sat

Light snow breaks out around 3 pm. Here is a simulated radar image for 4 pm

18z NAM hires Sim radar 4 pm Sat (Image Weatherbell)

Boston to Providence to Hardfort South and East flip to ice than rain quickly.  3-5 inches of snow falls in Southern Worcester County, NE CT, and N RI before a period of freezing rain and then plain rain.  The snow will thump before the changeover.  Further N and W stay colder and thus more snow. I am currently expecting a changeover around 10-11 pm in S WOR, NE CT, N RI.  Looks to be around midnight around 495 (north of pike). Early Sun AM for N Worcester county. Mainly snow out west.

Snow totals

NWS Boston snow totals. 

Again I feel slightly higher amounts are likely north of Providence.  Hi res radars suggest quite a thump before the changeover. Plus every storm has over performed in E Mass during the blitz.

Ice totals

NWS Boston Ice Forecast 

This is just a pain in the ass. There shouldn't be power outages but it will lead to poor road conditions.  Overall over a half inch of liquid will be added to the snowpack

WPC 2 day precip outlook

If you are interested keep an eye out for a general blog analyzing what effect this snow pack will have on spring.  I am looking for her. We will have to settle for low 40s...maybe Sunday.  I think mid to upper 30s is more likely but it will feel great. Arctic air returns Monday.

Have a great night/weekend,

-Zack Green