[Weather] [2019.12.30 4 AM Update] NWS Boston EM Briefing: Severe Icing Threat & Wintry Mix Thru Tonight

[BOX Operations - NOAA Service Account]

Good morning,

Here is the latest information on a storm that is currently ongoing across
Southern New England early this morning.

We are still expecting significant/severe higher-elevation icing for the
Berkshires into northern Worcester and northwest Middlesex Counties through
tonight. Lesser, though still impactful icing is still anticipated for most
areas west of Interstate 495.

*What has changed:*

Winter Weather Advisories which were previously in effect for eastern
Massachusetts and central Rhode Island have been *cancelled*. Freezing rain
is no longer expected to impact these areas. Mainly rain is now anticipated
for these locations.

Due to warmer surface temperatures, reductions in ice accumulations were
made. Significant icing is still expected in the higher terrain in the
Berkshires into northern Worcester County.

*Current Watches/Warnings/Advisories in effect:*

All warnings and advisories over land are in effect from tonight through
Tuesday AM

   - *Ice Storm Warning **for the eastern slopes of the Berkshires,
   northern Worcester County and northwest Middlesex County.* Here is where
   the most significant icing is expected due to a long duration of freezing
   rain. Severe impacts can be expected with extensive power outages and tree
   damage. This morning's commute will be treacherous in these areas, with
   continued impacts into this afternoon's commute as well.


   - Winter Weather Advisory *for northern CT, northern Providence County
   in RI and across western, central and northeast MA west of I-495*. Mix
   of precipitation types for these areas. Expect lesser, but still impactful
   accretions of freezing rain and sleet. This morning's commute will be slick
   for these locations, with slickened roads still possible into this
   afternoon's commute.

*Marine Watches/Warnings in effect:*

   - *Gale Warnings* for all of the coastal waters except for Narragansett
   Bay, through early Tuesday.


*Main Weather Concerns: *

1) *Severe icing across the higher elevations* *of* *western and north
central MA through tonight*. Coverage of freezing rain will continue to
expand early this morning and last into Monday evening. For the slopes of
the Berkshires, we still expect to have one half to three quarters of an
inch of ice with isolated amounts up to three-quarters of an inch. In
northern Worcester and northwest Middlesex Counties, one-quarter to
one-half inch of ice with isolated totals to two-thirds of an inch. East to
northeast winds will increase today, with gusts of 20-30 mph in the higher
terrain by late afternoon. This, coupled with the ice, could worsen the
impacts. By Tuesday, temperatures increase into the upper 30s and low 40s
in the higher terrain allowing for melting.

2)* Lower elevations: Lesser amounts of freezing rain (with some limited
periods of sleet at times) through today. *Accumulations of freezing rain
and sleet will continue to expand in coverage, and impact this morning's
commute. Additional light icing may impact this afternoon's commute as
well. Icing amounts range from a light glaze to one-quarter inch.

3)  *Strong east to northeast winds* are expected over the coastal waters
and along the South Coast this afternoon into tonight. Expect gusts of
40-45 mph across Cape Cod and the Islands tonight.

*What we are uncertain about:*

*Moderate to high confidence:*

   - Uncertain on the duration and exact precipitation type outside of the
   Ice Storm Warning areas.
   - Uncertain on the areal coverage and duration of sleet. With the
   tendency for warmer temperatures, freezing rain and/or rain should
   predominate as weather types with less sleet.


Attached images include the updated Winter Hazards in effect, and an
updated Storm Total Ice forecast based on our morning forecast.

Meteorologists: Andrew Loconto and Frank Nocera

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/20191230/edad9748/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: StormTotalIceISC_SFC.png
Type: image/png
Size: 118020 bytes
Desc: not available
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191230/edad9748/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hazards_SFC.png
Type: image/png
Size: 104971 bytes
Desc: not available
URL: <http://lists.massupt.org/pipermail/weather/attachments/20191230/edad9748/attachment-0003.png>