Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 222159

Area Forecast Discussion
National Weather Service Boston/Norton MA
559 PM EDT Thu Mar 22 2018

The coastal storm will move into the Maritimes tonight and
linger through the weekend. Upper level disturbances moving into
New Eng will bring the potential for scattered rain/snow
showers through the weekend with temperatures remaining below
normal. High pressure builds into the region Monday, then a
warming trend is expected through the middle of the week.



550 PM Update...

Scattered light rain/snow showers lingering along Cape Ann and
Cape Cod/Islands will diminish and move offshore during this
evening. Then dry conditions expected for the overnight.

Regarding winds and temps, a coastal front has set up, with the
westernmost extent from LWM-BED-OWD-PVD. Temperatures were much
cooler on the east side of this boundary, with temps in the mid
30s to low 40s. Utilized RAP/HRRR guidance for the next several
hours which captures this boundary, updating
winds/temp/dewpoint over the next few hours. Winds along the
shoreline should shift over to the NW after 8 pm with the
boundary washing out.

Otherwise, weak shortwave ridging moving into New England
combined with drying in the column will result in partial
clearing, but clouds will return later tonight ahead of the next
shortwave. Diminishing winds along the coast as storm moves
further away. Lows will drop into the 20s in most locations.



Mid level low over the Great Lakes digs SE into New Eng late in
the day. Deepening moisture moves in from the west which will
bring increasing cloud cover back into SNE. A few rain or snow
showers expected in the afternoon as low level lapse rates
increase. Temps below normal in low to mid 40s, except upper 30s
interior high terrain.

Friday night...

A few rain/snow showers may linger through the evening under the
mid level low, otherwise lots of clouds will persist across the
region. Lows will be mostly in the 20s.


High pressure system builds down from Quebec this weekend
advecting cold air over the region, keeping temperatures well
below normal through early next week. Global models are hinting
to a low pressure system that forms off the coast of the mid-
Atlantic and quickly intensifies. At the moment, models suggest
that the strong high over Quebec will keep the low pushed out to
sea. Regardless, if the low remains in close proximity to our
coast, winds and swell will increase and likely remain that way
until another system pushes it further east.

Otherwise, the high pressure will continue to build over the
region through Wednesday, before giving way to an approaching
cold front Thursday.


Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Short Term /through Friday Night/...

Thru 00Z...Moderate confidence. VFR most locations, except MVFR
with localized IFR along the Cape and Islands with lingering
rain/snow showers.

Tonight...Moderate to high confidence. Any lingering MVFR
on the Cape/Islands should improve to VFR. Otherwise...VFR

KBOS Terminal...Moderate confidence in TAF. VFR. East/NE winds
should shift to the NW after 00Z.

KBDL Terminal...Moderate to high confidence in TAF. VFR.

Outlook /Saturday through Tuesday/...Moderate Confidence.

Saturday: Mainly VFR, with local MVFR possible. Slight chance

Saturday Night: Mainly VFR, with local MVFR possible. Windy
with local gusts to 30 kt. Chance SHSN.

Sunday: Mainly VFR, with areas MVFR possible. Windy with gusts
to 30 kt. Slight chance SHSN.

Sunday Night: VFR. Windy with gusts to 30 kt. Slight chance

Monday through Monday Night: VFR. Windy with gusts to 30 kt.

Tuesday: Windy with gusts to 30 kt. Slight chance SHRA.


Short Term /through Friday Night/...High confidence.

Through tonight...Winds will gradaully diminish. Winds will
drop below SCA over eastern waters this evening, but hazardous
seas and SCA will continue for outer waters.

Friday and Friday night...Northerly winds below SCA. Seas will
gradually subside below 5 ft over eastern waters by Fri

Outlook /Saturday through Tuesday/...Moderate Confidence.

Saturday: Winds less than 25 kt. Slight chance of rain showers.

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas locally approaching 5 ft. Chance of
rain showers, slight chance of snow showers.

Sunday: Strong winds with gusts up to 30 kt. Areas of rough
seas. Chance of snow showers, chance of rain showers.

Sunday Night: Low risk for gale force winds with gusts up to
30 kt. Rough seas up to 10 ft. Chance of snow showers.

Monday through Monday Night: Low risk for gale force winds with
gusts up to 35 kt. Areas of rough seas. Slight chance of snow

Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Slight chance of rain


MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ232.
     Small Craft Advisory until 6 PM EDT this evening for ANZ233-
     Small Craft Advisory until 8 AM EDT Friday for ANZ231.
     Small Craft Advisory until 2 PM EDT Friday for ANZ250-254.
     Small Craft Advisory until 10 AM EDT Friday for ANZ251.
     Small Craft Advisory until 11 AM EDT Friday for ANZ255.
     Small Craft Advisory until 4 AM EDT Friday for ANZ256.


LONG TERM...Correia
MARINE...KJC/NMB is the U.S. government's official web portal to all federal, state and local government web resources and services.