South Berwick, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

623
FXUS61 KGYX 071825
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
225 PM EDT Sun Jun 7 2026

.WHAT HAS CHANGED...
Confidence is increasing in some degree of a heat risk during
the second half of next week. However, uncertainty remains in
regards to how high we could see temperatures get.

&&

.KEY MESSAGES...
1. A cold front continues to bring showers and storms into this
evening, followed by dry and seasonably warm conditions for
Monday.

2. Heat and humidity build the second half of this week
posing a heat risk, as well as chances for showers and
thunderstorms.

&&

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

A cold front continues to make slow progress through northern
New England this afternoon as low pressure tracks from Quebec
through eastern Maine. Scattered showers continue into the
evening hours, with isolated thunderstorms possible across
southern Maine and NH into the early evening hours. The front
then slides offshore by late this evening, with clearing behind
the front for overnight. With the recent rainfall and clear,
calm conditions overnight, valley fog is likely north of the
mountains tonight where the longest period of radiational
cooling is expected.

High pressure follows behind the front for tomorrow, with a
much drier airmass and seasonably warm temperatures. Near full
sunshine overcomes the cooler airmass to push highs into the mid
70s across the north, to low 80s downwind of the mountains
tomorrow. With light northwesterly flow, a light sea breeze
likely develops in the early afternoon, but is most likely to
remain confined to the immediate coastline.

The high shifts south of New England overnight tomorrow night,
setting up a warming trend going into midweek. The warming
airmass will already be evident by tomorrow night as lows
generally only fall into the upper 40s across the north, to mid
50s along the coast.

KEY MESSAGE 2 DESCRIPTION...
The forecast for this week is going to be dominated by ridging
over the Eastern Seaboard which is going to allow heat and
humidity to build over several days. As the ridge begins to take
hold in the first half of the week, global models are in good
agreement 850 mb temperatures quickly build to +12 to 14C, which
should result in low to mid 80s north of the mountains and mid
to upper 80s to the south. With northerly flow downstream of
the trough, dewpoints remain bearable in the 50s which should
make it feel pleasant. However, the ridge axis shifts east of
the area on Wednesday turning flow more southwesterly and
driving dewpoints up. This, combined with the building heat, is
going to make conditions feel more oppressive as the week goes
on. There is still some decent spread in the models, but the
middle of the road solution suggests 850 mb temperatures climb
to +16-18C (which is in the 90th percentile of climatology) by
the end of the work week, with dewpoints climbing into the upper
60s. The result would be a toasty second half of the week with
widespread ambient air temperatures in the mid to upper 80s and
near 90 in some of the normally warmer locations in the
Merrimack Valley. This of course means apparent temperatures
would be a little higher with those sticky dewpoints. I don`t
have the confidence to throw around the word heat wave yet (our
local definition requires 3 days with greater than 90F degree
temperatures), but I could see Heat Advisories eventually being
needed for parts of the CWA especially when considering heat
accumulation with nighttime temperatures potentially only being
able to drop into the mid-60s. As usual the higher terrain
should stay a bit cooler, as well as the coast where seabreezes
are all but guaranteed with little in the way of opposing flow.
Lastly, the increasing moisture means an increase in chances
for afternoon showers and thunderstorms. Coverage at this time
range is obviously uncertain, but there is currently nothing
that suggests it would be any more than the normal summertime
isolated to scattered pop-ups.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Showers continue to bring MVFR to IFR conditions into early
this evening, with VFR returning to most terminals by midnight.
VFR then prevails through tomorrow night, but some valley fog is
possible at HIE tonight, and then possible at HIE and LEB
Monday night.

Outlook...
Tuesday: VFR conditions expected under mostly clear skies.

Wednesday-Friday: Generally VFR conditions expected, but
afternoon showers and/or thunderstorms may bring about TEMPO
MVFR conditions.

&&

.MARINE...
Conditions remain below SCA levels as a cold front slowly
crosses the waters this evening. High pressure moves in behind
the front for Monday, and then slides south of New England
Monday night.

Quite conditions are expected on the waters with
afternoon seabreezes through next week as high pressure builds over
the Gulf of Maine and only slowly moves eastward.

&&

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

&&

$$

DISCUSSION...Baron/Clair