[Weather] [2020.02.05 AM] NWS Boston EM Briefing for Wintry Mix Thursday AM Commute

[BOX Operations - NOAA Service Account]

Good morning.

*Changes since the last update:*

   - A *Winter Weather Advisory* has been issued for most of the region,
   except southern Rhode Island and south coastal Massachusetts, beginning at
   1 AM Thursday morning. As temperatures slowly rise through the day, the
   advisory will end from SE to NW, lingering across NW Massachusetts through
   around 10 PM Thursday night.

Confidence remains high for a wintry mix of precipitation that will move
across the region early Thursday morning, impacting the morning commute.
Temperatures will rise through the day, though, so expect the snow to
change to rain from south to north by around midday.

A second stronger storm will approach by Thursday night, bringing rain
across most of the region. Heavy rain will fall across the region.  Pockets
of street and poor drainage flooding are likely, especially across north
central and northeast Connecticut, Rhode Island and from the Boston to
Providence corridor south and east to Cape Cod and the islands. Expect
temperatures to remain in the lower-mid 30s across northern Massachusetts
and the higher terrain, but there is a very low risk for some ice accretion
across the higher terrain through Thursday night.

Here are the details for the two events that will impact the region:

*1) Late Tonight through Thursday afternoon.*

*What/When/Where: *
- Precipitation starts as snow across western areas by around 1 AM,
reaching the east coast by 4 AM Thursday morning.  The snow will then mix
with sleet and freezing rain across S coastal areas by 4 to 5 AM, which
will lift northward during the morning commute.
- The wintry mix should change to rain from NE Connecticut to Rhode Island
and up to the Route 128 beltway by late Thursday morning. Sleet and
freezing rain will linger into early afternoon across parts of interior MA
& N central CT before changing to rain by late afternoon across the higher
terrain.
- Rain will linger into Thursday evening.

*Potential Snow/Ice Accumulations: *
- Snow and sleet accumulations from a coating to 3 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 continues that the wintry mix will occur during 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  the highest terrain of the Berkshires and northern
Worcester Hills which should change to rain Thursday evening.

*2) Thursday night and Friday Event:*

*Potential Impacts / Uncertainty:*
*- *This stronger storm will bring an area of heavy rain across the region,
with rain amounts up to 1.5 to 2.5 inches. This may result in some street
and poor drainage flooding, with the best chance occurring across northeast
Connecticut, Rhode Island and southeastern Massachusetts where the highest
amounts will fall late Thursday night to midday Friday.
- Temperatures should rain above freezing across the interior Thursday
night and Friday morning, so no additional ice accretion is expected.
- Rain may change to snow Friday afternoon and early evening with a few
inches of accumulation possible.  Highest risk for light snow accumulations
will be across northern Massachusetts.

Attached please find the latest forecasted snow and ice amounts through
Thursday afternoon.

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
<http://www.twitter.com/NWSBoston>
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