[Weather] [2019.12.28 AM] NWS Boston EM Briefing: Wintry weather with possible ice event Sunday night into Tuesday

[BOX Operations - NOAA Service Account]

Good morning,

Following is an update on a complicated storm system that is expected to
bring a wintry mix to interior Southern New England starting Sunday night.

While much of this wintry weather event will be mainly Sunday night thru
Monday night, a continuation of wintry weather accumulations is possible in
parts of northern and northwest MA into Tuesday.

*What Has Changed*:

*Winter Storm Watch Issued:* In effect from Sunday Night until Tuesday
Afternoon for northern CT into western and central MA.

*Main Weather Concerns:  *

1) *Possible ice storm* in the higher terrain of western and central MA
(eastern slopes of the Berkshires & Worcester County hills) into Tolland,
Windham and western Hartford Counties in CT.  Freezing rain is expected to
begin in those areas Sunday evening and continue into Monday evening, with
temperatures around 28-30 degrees.

While some of these areas may transition to rain into Tuesday, additional
light freezing rain, sleet or snow accumulations are possible across
northwestern MA.

Current projections are for between 0.25 and 0.50 inches of ice accretion
(and potentially greater than 0.50" in some locations) in the Winter Storm
Watch area.

Uncertainty continues as to the amounts and timing of precipitation type
transitions.

2) *Mixed bag of snow, sleet, freezing rain, and rain during the morning
commute on Monday. * Any snow on the front end in northeast MA is expected
to be short-lived and turning over to sleet and rain Sunday night into
Monday. Lesser accumulations of freezing rain and sleet are expected across
northern RI into the I-495 corridor in eastern MA.

*Confidence...and what could still change:*

We have high confidence that this storm system will occur and produce a
wintry mix.

While confidence has increased on precipitation types and the potential for
significant icing in the Watch area, there remains low to moderate
confidence on accumulations and distribution of precipitation types in
northern RI into northeast MA.  A colder scenario than currently forecast
would mean less freezing rain and possibly significantly more sleet and/or
snow.

The potential exists for higher freezing rain totals in the high terrain of
western and central MA into northern CT, which, if true, could lead to
power outages and downed trees/wires.


Attached images are the current Winter Storm Watch area, and forecast snow
and ice accumulations.


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>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191228/ac95a0ee/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: StormTotalSnowISC_SFC.png
Type: image/png
Size: 114293 bytes
Desc: not available
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191228/ac95a0ee/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: StormTotalIceISC_SFC.png
Type: image/png
Size: 124070 bytes
Desc: not available
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191228/ac95a0ee/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hazards.png
Type: image/png
Size: 155304 bytes
Desc: not available
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191228/ac95a0ee/attachment-0005.png>