376
FXUS61 KBOX 092252
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
552 PM EST Sat Nov 9 2024

.SYNOPSIS...
Very cold start to Sunday will be followed by moderating
temperatures and a progressive low-pressure system that is expected
to bring a much needed soaking of rain Sunday night into Monday.
Dry conditions return late Monday through Wednesday before
another low- pressure system could bring rain again on Thursday.

&&

.NEAR TERM /THROUGH SUNDAY/...

Tonight

High pressure builds over southern New England tonight allowing
gusty winds from this afternoon to diminish to the light and
variable category. Air mass remains bone dry with PWATs just above a
quarter of an inch. Given clear skies, light winds, and dry
conditions we can expect strong radiational cooling overnight. Opted
to run with the minimum of all guidance for low temperatures tonight
which yields widespread temps in the low to mid 20s across southern
New England. The proximity to the ocean should keep the coastal
locations a bit more mild in the low to mid 30s.

&&

.SHORT TERM /SUNDAY NIGHT/...
Tomorrow

High pressure shifts east on Sunday allowing return flow from the
southwest to support moderating temperatures Sunday afternoon. Warm
air advection in the low-levels will support an uptick in high
temperatures from Saturday with mid to upper 50s common across the
forecast area. RH continues to run low, below 40 percent for most of
the region Sunday afternoon. With modest southwest winds from 10 to
15 mph tomorrow, we have continued The Red Flag warning for elevated
fire weather concerns given the unusual stretch of dry weather.
After a sunny start, we will experience increasing cloud cover
during the mid to late afternoon hours as a frontal wave approaches
from The Midwest.

Tomorrow Night

A progressive frontal wave will bring a much needed soaking of rain
to southern New England tomorrow night into Monday morning.
Southwest flow ahead of the associated cold front will support a
surge in moisture of southern New England with PWATs rising nearly
an inch to 1.2 to 1.3 inches along the south coast. Given only
modest forcing and the progressive nature of this system, we`re only
expecting 0.1 to 0.25 inches of rainfall for most of the region.
While this isn`t nearly enough to make up recent deficits, it may
bring some much needed relief to locations in southern New England
that have had notable brush fires dating back to last week. Showers
taper off by mid morning Monday as the associated short-wave aloft
propagates east over The Canadian Maritimes.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Highlights...

*Rain exits early Monday with unseasonably warm temperatures to
follow

*Colder Tuesday and then even moreso Wednesday into late week with
highs in the 40s

*Next chance of rain comes Thursday but confidence that we`ll see
appreciable precip materialize is quite low

Details...

While rain should be done by mid morning Monday, the upcoming work
week will start off with a bit of a temperature roller coaster as
high temps rocket back up into the 70s Monday before returning to
the 40s and 50s behind. This quick drop comes thanks to a cold front
that moves through on Tuesday associated with a shortwave crossing
northern New England during that period. The associated surface low
will serve to tighten the pressure gradient and make for some gusty
winds on Tuesday into early Wednesday before mid level ridging
returns mid week.

Beyond Wednesday we`ve been eyeing a potentially potent system with
hopes it will bring us a more substantially wetting rain. Not that
that outcome is out of the cards, but trends have not been our
friend with some global guidance showing a more quick, transient
system and some like the ECMWF with a miss completely in the 12Z
run. We of course don`t want to rely on a deterministic run, and the
EC ensembles continue to indicate a 30-50% chance of at least 0.01"
of rain Thursday (though zero chance of anyone getting a half inch
or more). Stay tuned.

As we go into the weekend obviously confidence decreases
substantially in the details as they`ll ride on how Thursday`s
system plays out, but the return of mid level ridging (dry weather)
looks likely.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

00Z Update...

Tonight...High Confidence

VFR. Light Northwest winds becoming light out of the southwest
by 12Z.

Tomorrow...High Confidence

VFR. Southwest winds around 10 knots.

Tomorrow Night...High Confidence

SHRA/-SHRA overspreads southern New England between 00Z and 06Z.
Ceilings falling to MVFR category with embedded IFR. MVFR vsybs
possible in showers. Steady 10-12 knot southwest winds with
some higher gusts greater than 20 knots over The Cape/Islands.

KBOS TAF...High Confidence in TAF.

KBDL TAF... High Confidence in TAF.

Outlook/Monday through Wednesday/

Veterans Day: Mainly VFR, with local IFR possible. Breezy.
Chance RA.

Monday Night: VFR. Breezy.

Tuesday through Tuesday Night: VFR. Windy with local gusts up
to 30 kt.

Wednesday: VFR. Breezy.

Wednesday Night: VFR.

Thursday: Mainly VFR, with local MVFR possible. Chance RA.

&&

.MARINE...
Forecaster Confidence Levels:

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


Tonight and Tomorrow

Subsiding seas and diminishing winds will result in sub-SCY
conditions across the coastal waters overnight. Relatively calm
conditions persist into tomorrow, but with southwest winds
increasing to 15 to 20 knots by tomorrow evening.

Tomorrow Night

Area of low-pressure moves over The Northeast tomorrow night. This
will support the return of SCY criteria at least over the southern
marine zones where 5 foot significant wave heights and 25 knot gusts
are forecast.

Outlook /Monday through Thursday/...

Veterans Day: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Chance of rain. Local
visibility 1 to 3 nm.

Monday Night: Winds less than 25 kt. Local rough seas.

Tuesday: Moderate risk for Small Craft Advisory winds with
areas of gusts up to 30 kt. Seas up to 5 ft.

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

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Areas of rough seas.

Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of rain.

Thursday: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain.

&&

.FIRE WEATHER...
The prolonged period of dry weather coupled with a very dry
ground will continue to result in elevated fire weather concerns
through Sunday afternoon. Chilly night expected for tonight, with
light northerly winds. For Sunday, full sun should begin the
day but with increased cloud cover by the afternoon. Southwest
winds on Sunday will pick up to around 20 mph in gusts.

A frontal system brings welcomed light rain overnight Sunday night
ending by Monday morning. Rain amounts are expected to be no greater
than a quarter inch.

Minimum relative humidities on Sunday are expected to be as low as
30 to 40 percent, and around 50 percent for the Cape and Islands.
On Monday, expect relative humidities to be around 50 to 60
percent.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Red Flag Warning until 6 PM EST this evening for CTZ002>004.
     Red Flag Warning from 9 AM to 6 PM EST Sunday for CTZ002>004.
MA...Red Flag Warning until 6 PM EST this evening for MAZ002>024-
     026.
     Red Flag Warning from 9 AM to 6 PM EST Sunday for MAZ002>024-
     026.
RI...Red Flag Warning until 6 PM EST this evening for RIZ001>008.
     Red Flag Warning from 9 AM to 6 PM EST Sunday for RIZ001>008.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ231-
     232-251-256.
     Small Craft Advisory until 1 AM EST Sunday for ANZ250.
     Small Craft Advisory until 7 AM EST Sunday for ANZ254-255.

&&

$$

SYNOPSIS...BW/RM
NEAR TERM...RM
SHORT TERM...RM
LONG TERM...BW
AVIATION...BW/RM
MARINE...BW/RM
FIRE WEATHER...BW/RM