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Area forecast discussion
National Weather Service Boston/Norton Massachusetts
134 am EST Wed Nov 13 2019

Synopsis...
high pressure builds in from the Midwest, becoming centered over
New England Wednesday night. It will bring record cold
temperatures, along with strong winds, tonight and Wednesday.
Temperatures begin to moderate on Thursday, but will still be
below normal for the middle of November. Even milder weather is
on tap for Friday, but that will be short-lived as another cold
front Ushers in a return to well below normal temperatures
later Friday night and Saturday. An offshore storm may impact
our region early next week. Temperatures should moderate some
early next week.

&&

Near term /until 6 am this morning/...
135 am update...

As of 135 am, skies were clear across the entire region, except
for high cloudiness across Cape Cod and the islands. It was cold
with temperatures in the teens to mid 20s. Winds were gusting up
to 30 mph at times, especially in the higher terrain and along
the coast. This may prevent temperatures from bottoming out in
the single digits in northwest MA, although that's still
possible.

&&

Short term /6 am this morning through 6 PM Thursday/...
high pressure builds east Wednesday, moving over New England
Wednesday night. The pressure gradient continues during the
morning but diminishes in the afternoon.

Dry air and subsidence should bring sunny skies during the day.
Curious whether the northwest flow of -15c air over +10-12c
surface water might generate ocean effect clouds/pcpn over the
Outer Cape. Low level shear is minimal. Model data doesn't
indicate any moisture, but it bears watching.

The mixed layer reaches at lest 925 mb and possibly 900 mb.
Temps aloft at the top of the layer are forecast at the 850
equivalent of -17c to -18c, which supports Max temps in the mid
to upper 20s. The warmer waters could bring temps up a little
more along the coast. Will forecast Max temps of 25f to 35f.

Wednesday night...

High pressure overhead will mean light wind and clear skies,
with potential for radiational cooling in the interior. Holding
on to min temps in the teens, but with dew points in the single
numbers the cold spots may easily reach single numbers.

&&

Long term /Thursday night through Tuesday/...
highlights...

* moderating temps Thu, but still below normal

* seasonable temperatures briefly return Fri, but turning cold
again by Sat

* watching offshore storm late sun into Tue with moderating
temperatures

This portion of the forecast will generally feature near to
below normal temperatures and moisture content. Temperatures
should gradually moderate Thursday through Friday, then another
surge of colder air arrives Friday night into Saturday night.
Temperatures should then start to gradually moderate once more
Sunday through Tuesday.

High pressure nearby our region should maintain dry weather
through much of Sunday. The exception may be Thursday night as a
moisture- starved cold front crosses our region. The greatest
risk for a stray shower or two will be towards southeastern New
England.

The next risk for more significant precipitation is expected to
be sometime Sunday night into Tuesday, as a low pressure
meanders up the eastern Seaboard. There remains quite a bit of
uncertainty as to the track of this low pressure, and how close
it will be to southern New England. Kept a chance of
precipitation in the forecast at this point, but the details are
likely to change with later forecasts this week. Rain would be
favored, but cannot completely shut the door on the possibility
for some snow.

&&

Aviation /07z Wednesday through Sunday/...
forecaster confidence levels...

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

Short term /through Thursday/...high confidence.

0635z update...

Overnight...high confidence.

VFR. Northwest gusts 20-30 kt.

Wednesday...high confidence.

VFR. Gusty northwest winds in the morning, diminishing in the
afternoon.

Wednesday night... high confidence.

VFR.

Kbos terminal...high confidence in taf.

Kbdl terminal...high confidence in taf.

Outlook /Thursday night through Sunday/...

Thursday through Thursday night: mainly VFR, with local MVFR
possible. Breezy.

Friday: VFR. Breezy.

Friday night through saturday: VFR. Windy with gusts up to
35 kt.

Saturday night: VFR. Windy with local gusts up to 30 kt.

Sunday: mainly VFR, with areas MVFR possible. Breezy.

&&

Marine...
short term /through Thursday/...high confidence.

135 am update...

Gale warnings continue over all waters overnight and Wednesday
morning. Northwest winds gusting to 30 to 40 kt overnight and
Wednesday morning, diminishing in the afternoon. Seas 5-10 feet
on the exposed waters, highest on the outer waters. At 930 PM,
the steamship authority reported 4 to 5 ft seas on Nantucket
Sound.

High pressure builds over New England Wednesday night. Expect
winds diminishing to less than 25 kt. Seas of 5 feet linger on
the outer waters the first half of the night.

Outlook /Thursday night through Sunday/...

Thursday: winds less than 25 kt.

Thursday night through friday: winds less than 25 kt. Areas of
seas approaching 5 ft.

Friday night: low risk for gale force winds with gusts up to
35 kt. Areas of rough seas.

Saturday: moderate risk for gale force winds with gusts up to
35 kt. Rough seas up to 12 ft.

Saturday night: moderate risk for Small Craft Advisory winds
with local gusts up to 30 kt. Rough seas up to 10 ft.

Sunday: moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Rough seas up to 10 ft. Slight chance of rain
showers.

&&

Climate...
record low min temps for Wednesday Nov 13

Boston 14/1883
Hartford 18/2001
Providence 20/2001
Worcester 15/1986

Record low Max temps for Wednesday Nov 13

Boston 36/1874
Hartford 33/1911
Providence 37/1911
Worcester 32/1962,2013

Record low min temps for Thursday Nov 14

Boston 16/1905
Hartford 15/1986
Providence 16/1905
Worcester 10/1986

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Gale Warning until 1 PM EST this afternoon for anz231>235-237-
250-251-254>256.
Gale Warning until 7 am EST this morning for anz230-236.

&&

$$
Synopsis...wtb/Belk/field
near term...field
short term...wtb

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