Good afternoon everyone,

Here is the latest forecast update regarding the snow event Saturday afternoon & evening ...

What has changed ...
  • Winter Storm Warnings for 4-7" of snow have been posted for western & northern portions of MA and Litchfield county of northwest CT
  • Winter Weather Advisories for 2-4" of snow have been posted for the remainder of MA/RI and CT except no headlines for south coastal MA and RI including Cape Cod and the Islands where 1-3" of snow is expected before changing over to rain before ending.
Timing ... 
  • Snow overspreads the area Saturday between 3 pm to 6 pm from west to east
  • Precipitation begins to taper off between 10 pm and 1 am from west to east
Duration ... 
  • This is a fast moving system so precipitation will be limited to roughly a 3-6 hour window
  • Here is an approximate timeline of the steadiest snow/precip - Boston: 6pm to midnight, Worcester to Springfield 5 pm to 11 pm, Providence 6 pm to 10 pm, Hartford 4 pm to 10 pm
Impacts ...
  • Not a block buster snow event but it will snow moderately for a 3-6 hour window (times above) with snowfall rates up to an inch per hour possible during this time. 
  • This will result in roads becoming snow covered late Saturday afternoon and evening along with poor visibility.  Travel will become difficult during this time.
Snow Totals ... 
  • Most of MA, RI & CT will receive 2-4 inches of snow before snow briefly changes over to rain and/or a wintry mix before ending around midnight or shortly thereafter
  • Western & northern Massachusetts along with northwest CT will likely receive the highest totals of 4 to 8 inches while the south coast of MA and RI likely only receive 1-3 inches before changing to rain before ending. This includes Cape Cod and the Islands.  
Forecast Confidence ... 
  • Still some uncertainty on the exact timing of the changeover from snow to rain or a brief wintry mix.  Therefore three snowfall maps are included to express this uncertainty, StormTotalSnow (most likely snowfall), SnowAmt10PrcntilISC (low end amount) and SnowAmt90PrcntilISC (high end amount).  Given the very cold airmass over the region late today and continuing overnight with morning lows Saturday in the single digits and teens, this may delay the changeover and result in an hour or two of additional snowfall.  Therefore our most likely snowfall map is very close to the high end snow map.
Given the event is still about 24 hours away the exact timing may change by an hour or two with later forecasts along with snow amounts increasing or decreasing by an inch or two.  Thus stay tuned to later forecasts and discussions.  The next email briefing will be issued around 4 am to 5 am Saturday.

Frank Nocera

If you have any questions or would like more information, don't hesitate to contact us via this email address, on NWSChat, or at the following:

National Weather Service Boston/Norton, MA

46 Commerce Way
Norton, MA 02766
508.622.3280
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