Area Forecast Discussion
Issued by NWS Portland, ME

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929
FXUS61 KGYX 312324
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
724 PM EDT Mon Aug 31 2026

.WHAT HAS CHANGED...
Few changes needed for this quiet Monday evening update. Just
blended in the latest observations to the going forecast.

&&

.KEY MESSAGES...
1. Low pressure tracking along a stationary front will provide a
focus for clouds and rain Tuesday, mainly across south-central NH
and SW Maine.

2. An unsettled pattern brings the best chance for widespread
rainfall late Wednesday and Thursday.

3. A gradual drying trend follows for Friday and Labor Day
weekend.

&&

.DISCUSSION...
KEY MESSAGE 1 DESCRIPTION...

Latest surface analysis places a stationary front from the northern
Great Lakes ESE through Long Island, NY with high pressure over SE
Canada into northern New England. High pressure will keep much of
the area mostly dry tonight as a wave of low pressure starts to form
along the stationary front. Valley fog will be likely for portions
of the CT Valley as well as northern valleys where radiational
cooling will be more efficient.

Clouds will advance northeastward across NH late tonight as the
wave of low pressure nudges the stationary front northward. Rain
will become likely across southern NH by day break with rain
spreading northward Tuesday morning. Models are in reasonable
agreement that high pressure will hold firm over SE Canada and
will limit rain chances north of a line from the White Mountains
to KLEW to KRKD. Rainfall will generally be light, while some
elevated instability combined with PWATs greater than 1.5 inches
could lead to some localized heavier rates over NH. Chances for
rain will diminish Tuesday evening into Tuesday night from NE
to SW as the wave of low pressure tracks SE offshore of Cape
Cod. Total rainfall will approach 0.75 inches across SW NH and
will diminish to the northeast. Otherwise it will be cooler
Tuesday with highs in the low 70s while northern areas that see
more sun could push into the mid 70s.

KEY MESSAGE 2 DESCRIPTION...

A more widespread and robust round of showers and storms
approach the area from the west on Wednesday. Most of the day on
Wednesday itself looks mainly dry, with the best chance for
some scattered showers across the higher terrain. By late in the
day, the more widespread round of showers begins to push into
western New Hampshire.

A weak low pressure center gradually organizes as it moves
through New England Wednesday night and Thursday. This likely
brings a round of steady rain and heavier showers to all of the
forecast area, with the potential for a widespread 0.75 to 1.5
inches of rain, the most a lot of towns have seen in a while.
The steadiest rain looks to fall during the overnight hours
Wednesday and the first half of the day on Thursday. The chance
for showers persists through the afternoon on Thursday.

KEY MESSAGE 3 DESCRIPTION...

Overnight Thursday night and Friday, a trough deepens across
Nova Scotia while the surface low pressure deepens as well. This
consolidates most of the unsettled conditions to the east of
New England by Friday, and leaves us on the western edge of the
trough. This results in a drier and cooler pattern with
northerly flow. The bulk of the heat under a large ridge
affecting much of the eastern 2/3 of the country remains west of
New England. So while we won`t break into the warmth, being on
the western edge of the trough brings a drier outlook for the
weekend than previous model runs were suggesting from the last
few days.

Highs in the 70s look to prevail for most of the area from
Friday through at least Sunday, with nighttime lows in the 40s
to low 50s. Being under the influence of the trough, mornings
will be the sunniest part of the day, with pop up clouds and
scattered showers likely a feature each afternoon from Friday
through Sunday. The chances for showers progressively lower each
day, and are most likely across the higher terrain.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Through Tuesday night...Mainly VFR through 06Z tonight.
Thereafter, valley fog likely brings IFR/LIFR to LEB and HIE.
MVFR cigs and -RA move into southern NH by 12Z and expand north
and east to LEB, CON, and PWM through Tuesday morning. Cigs may
lower to IFR thresholds at times into Tuesday afternoon. HIE,
AUG, and RKD likely stay VFR through the day Tuesday. Onshore
flow may allow for a period of IFR cigs across much of the area
Tuesday evening into the first half of Tuesday night with some
improvement to MVFR/VFR towards Wednesday morning.


Outlook...

Wednesday-Thursday: MVFR more likely by late Wednesday at most
terminals with showers.

Thursday night-Friday: Improving conditions, with MVFR still
possible in brief showers. Valley fog is possible at LEB and
HIE.

Friday night - Sunday: Mainly VFR during the daytime, but brief
MVFR ceilings remain possible in afternoon showers. Nighttime
valley fog is likely at HIE, LEB, and CON, and still possible at
all other terminals.

&&

.MARINE...
Winds and seas remain below SCA thresholds through Tuesday
night. Low pressure will track along a front south of the waters
Tuesday bringing steady SE to E flow and periods of rain.
Chances for rain diminish Tuesday night as the low tracks
southeast of Cape Cod.

A broad developing low pressure system approaches from the west
Wednesday night, crossing the waters on Thursday. A period of
SCA conditions are possible in southerly flow ahead of this
system on Thursday. Northerly flow brings a return to fair
conditions Thursday night and Friday. Marginal SCA conditions
are then possible across the outer waters this weekend in
northerly flow as low pressure deepens across Atlantic Canada.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$

DISCUSSION...Clair/Hargrove/Schroeter