Tracking Snow Chances This Week

A few light snow events are likely this week as the pattern changes back towards a more typical early February pattern.  The upper air pattern has changed but surface temperatures have remained above normal.  This begins to change tonight when a cold front from Canada brings a shot of Arctic air.  The coldest air remains in Northern New England but temperatures in the upper 40's appear to be the exception, not the rule going forward.

General Overview
The surface chart as of 8 AM shows the Arctic boundary beginning to enter the Great Lakes.  A powerful dome of high pressure has built in the Western US.

WPC Surface Analysis 8 AM

Here is the 12 PM forecast for the entire US.  Notice the coldest air behind that cold front in Canada.

14z HRRR 2 m temperatures Sunday 12 PM (image Weatherbell)

National temperature anomalies show below average temperatures under the high in the west and in parts of the Eastern US.  It is warm in the Central US and along the immediate West Coast.

NWS max temperature anomaly Sunday 1/29 (image Weatherbell)

Pacific air is being forced up and over the dome of high pressure in the west and then down the Eastern slopes of the Rockies into the Plains.

12z GFS 500 mb height anomalies Sunday 1 PM (image Weatherbell)

The water vapor satellite shows storm systems moving into the Pacific Northwest and down into the Plains.  It also shows clouds ripping across South Florida.

NOAA/NCEP/NWS GOES Composite Water Vapor Satellite 

Short Term Forecast
As the Arctic boundary sags south it will fall apart.  Clouds will increase this afternoon with a slight chance of a snow shower.  Winds will be out of the west and shift to the northwest later today.  Temperatures begin to fall this evening.   Low temps drop into the low 20's.

NWS Minimum Temperature Forecast Sunday Pm-Monday Am (image Weatherbell)

Max temperatures Monday are in the low to mid 30's.  I expect more clouds than the sun as an area of low pressure will pass South and East of New England.  A few snow showers are possible for the Cape and Islands.

WPC Surface Fronts/Precipitation Monday 7 AM

Temperatures will drop into the teens Monday night into Tuesday.  A period of snow is likely on Tuesday as a clipper moves through the region.  Precipitation should begin after 7 AM.  School closings/delays do not appear likely.

WPC Surface Fronts/Precipitation Tuesday 7 AM (image Weatherbell)

Expect max temperatures in the mid to upper 20's on Tuesday.  Light accumulations expected.  I'll update tomorrow.

-Zack Green