[Weather] [2020.02.04 PM] NWS Boston EM Briefing For Wintry Mix Thursday AM Commute

[BOX Operations - NOAA Service Account]

Good afternoon everyone,

High confidence that a wintry mix that will impact the Thursday morning
commute, but amounts will be light.  A second stronger storm will impact
the region Thursday night into Friday, but there is more uncertainty how we
are impacted. Heavy rain and pockets of street flooding are possible across
Rhode Island and Southeast MA.  There is also a low probability for
significant ice accretion across the interior high terrain of
Massachusetts, but uncertainty is high given temperatures right near
freezing.  We have included a brief outline below and some graphics. Please
note that the graphics only include the first event.

*1) Late Wednesday Night Into Thursday Afternoon Event*

*What/When/Where: *
- Precipitation starts between 2 and 5 AM  Thursday morning.  Main
precipitation type will initially be sleet and freezing rain, but a brief
period of snow is possible at the onset with the best chance across
northern MA.
- The wintry mix should change to rain along and southeast of the Boston to
Providence corridor by late Thursday morning.  Sleet and freezing rain will
linger into the afternoon across parts of interior MA & CT, but begin to
taper off.
- Most locations should have ended as light rain or drizzle by late
Thursday afternoon, but a few pockets of lingering freezing drizzle can not
be ruled out across the high terrain of the Berkshires and northern
Worcester Hills.

*Potential Snow/Ice Accumulations: *
- Snow and sleet accumulations of a coating to 2 inches are expected. The
best chance of seeing an inch or two of snow and sleet will be north of the
Massachusetts Turnpike.
- Ice accretion on the order of a few hundredths to one tenth of an inch
are expected for much of southern New England

*Impacts/Uncertainty: *
- High confidence that the wintry mix will coincide with the Thursday
morning rush hour, despite relatively light amounts of snow and ice.
- The biggest uncertainty is whether or not we initially see a few inches
of snow in northern MA or mainly just sleet and freezing rain.  Either way,
the Thursday morning rush hour will be impacted.
- Confident that most of the region will be above freezing by late Thursday
afternoon, except perhaps the highest terrain of the Berkshires and
northern Worcester Hills.

*2) Thursday night and Friday Event:*

*Potential Impacts / Uncertainty:*
*- *This will be a much stronger storm than the first event, but more
uncertainty in regards to how we are impacted.
- 1 to 3 inches of rain is possible which may result in some street
flooding especially across Rhode Island and Southeast Massachusetts.
Heaviest rain late Thursday night into early Friday morning.
- Temperatures might be marginally cold enough for freezing rain / icing
across portions of interior Massachusetts. Low probability for 0.25 to 0.50
half inch of ice accretion in parts of the Berkshires and northern
Worcester Hills.
- Rain may change to snow Friday afternoon and early evening with a few
inches of accumulation possible.  Highest risk for that is across northern
Massachusetts.
*- Biggest concern is the potential for ice accretion to reach one half
inch across parts of the Berkshires and Worcester Hills.  While a low
probability, this would bring the potential for scattered power outages.*

Thank You

Meteorologist: Hayden Frank and Rodney Chai

If you have any questions or would like more information, don't hesitate to
contact us via this email address, on NWSChat <https://nwschat.weather.gov/>,
or at the following:

National Weather Service Boston/Norton, MA
46 Commerce Way
Norton, MA 02766
508.622.3280
Website <http://www.weather.gov/boston> | Facebook
<http://www.facebook.com/NWSBoston> | Twitter
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