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000
FXUS61 KBOX 031919
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
319 PM EDT Tue Oct 3 2023

.SYNOPSIS...
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High pressure will continue to provide dry and very pleasant fall
weather through Thursday. Other than early morning fog each day,
lots of sunshine is expected with the warmest temperatures on
Wednesday, with another round of highs in the low 80s. Still
unseasonably mild Thursday, with highs in the 70s. A strong
frontal system then slowly moves into Southern New England
Friday night and Saturday. While rain amounts are still uncertain,
there is growing confidence on a widespread rain and perhaps heavy
at times. Rain comes to an end either Saturday evening or overnight.
Then dry but brisk and cooler weather overspreads the region Sunday
into early next week.
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&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

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315 PM update...

Pleasant, warm Fall day in progress beneath a sprawling surface high
pressure and mid level ridge covering much of the eastern U.S. this
afternoon. Warm, moist advection tonight on WSW winds will bring
increasing dewpoints this evening into tonight, rising into the low
60s for most. This will act to keep low temperatures from dropping
as low as the last few nights, as well as increasing the likelihood
of patchy dense fog.
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&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...

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315 PM update...

Wednesday expect more of the same under the influence of the same
high pressure ridge; we`ll see temperatures well above average,
especially in the interior where highs top out in the low 80s. For
locations along the coast seabreezes will keep temperatures more
comfortable in the mid 70s. Another mild night Wednesday night given
elevated dewpoints, with lows dipping into the low to mid 50s.
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&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

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315 PM update...

Key Points:

* Dry and very pleasant weather with warmer than normal temperatures
  continuing Thursday

* Increasing chances for showers Fri, with a more widespread rain
  Friday night and Saturday.  Rain may be heavy at times.

* Dry weather returns Sunday and continues into early next week, but
  noticeably cooler and brisk at times

Thursday...high amplitude closed anticyclone over the region
provides another day of dry, very pleasant fall weather to SNE, with
lots of sunshine given subsidence/very dry column via PWATs below
normal. The anomalous warmth from Tue and Wed will be tempered Thu
by low level southerly flow. Blyr mixing will be limited by
subsidence inversion/1025 mb surface high.  925 mb temps around
+18C, which should support highs in the mid to upper 70s.
Nonetheless, still about 10 degs warmer than normal and it will feel
warm with dew pts in the low 60s.

Friday...high amplitude mid level trough comes barreling through
the Great Lakes Friday. Not expecting a washout here Friday as
deeper moisture holds off until Fri night/Sat, but can`t rule out a
few low top showers Friday. Not as mild Fri given onshore SE flow
and more clouds than sun. Although still a few degs above normal
with highs in the upper 60s and lower 70s. However, it will feel
mild with dew pts in the low to mid 60s.

Fri night/Saturday...showers become more widespread Fri night and
Sat with increasing cyclonic flow as approaching trough takes on a
negative tilt and possibly evolves into a closed mid level low.
Strong jet dynamics with RRQ of upper level jet streak over SNE,
coupled with tropical moisture from Philippe possibly being
entrained into the trough, may result in periods of heavy rain and a
flood threat. All three ensemble systems (ECENS, GEFS & CMC) have a
few members with 2+ rainfall amounts, which is a pretty strong
signal given the time range here. Seems plausible given amplitude of
upper air pattern combined with tropical moisture. Obviously still
uncertainty on location of heaviest rainfall. Something we will need
to watch as the week progresses.

Sunday into early next week...cooler than normal with below normal
heights over the Northeast/New England. Highs in the upper 50s and
lower 60s, and widespread lows in the 40s with a few MU30s. Mainly
dry but lots of diurnal clouds and possibly a brief afternoon shower
early next week, especially high terrain.
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&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
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Forecast
Confidence Levels:

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

18Z TAF Update:

This afternoon: High confidence.

VFR. Winds generally W/WSW, less than 10kt.

Tonight...High Confidence.

VFR except for patchy IFR/LIFR at fog prone terminals like BAF,
BDL, and BED prior to sunrise. Calm winds.

Wednesday...High Confidence.

VFR. Fog lifts by 15z. Winds NNW/N becoming E/NE less than
10kt.

Wednesday night...High confidence.

VFR. Fog once again possible. Light S winds.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Thursday through Sunday/...

Thursday: VFR.

Thursday Night: Mainly VFR, with local IFR possible.

Friday: Mainly VFR, with local IFR possible. Slight chance
SHRA.

Friday Night: MVFR/IFR conditions possible. Breezy. Chance
SHRA, isolated TSRA.

Saturday: Mainly MVFR, with areas IFR possible. Breezy. SHRA
likely, slight chance TSRA.

Saturday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA, isolated TSRA.

Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA.
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&&

.MARINE...
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Forecaster Confidence Levels:

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

Quiet conditions with surface high pressure in control. Dry weather
with light wind from the west/southwest this afternoon and then
becoming east-southeast across the northern waters and more
southerly over the southern waters for Wednesday. Wind speed and
gust are well below advisory criteria, 10 to 15 knots and seas are
generally less than 2 to 4 feet. Wednesday nights light winds turn
out of the south.

Outlook /Thursday through Sunday/...

Thursday through Friday: Winds less than 25 kt.

Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.

Saturday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Chance of rain showers,
slight chance of thunderstorms.

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 10 ft. Chance of rain
showers.

Sunday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Rough seas up to 10 ft. Chance of rain showers.
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&&

.CLIMATE...

Record Daily High Temperatures for October 3rd

BOS 85 in 1922
BDL 85 in 1919
PVD 83 in 1919 and 1922
ORH 83 in 1898

Record Daily High Temperatures for October 4th

BOS 86 in 2007
BDL 86 in 2007
PVD 85 in 1941 and 1959
ORH 85 in 1898 and 1931

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$
SYNOPSIS...Nocera/BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...Nocera
AVIATION...Nocera/BW
MARINE...Nocera/BW
CLIMATE...Staff