Topsham, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

075
FXUS61 KGYX 250023 AAA
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
823 PM EDT Sun May 24 2026

.WHAT HAS CHANGED...
For forecast is generally evolving as expected. No major
changes.

&&

.KEY MESSAGES...
1. Wet weather continues on and off through Memorial Day. An
isolated thunderstorm is possible late tonight or early Memorial
Day across portions of coastal/interior Maine.

2. A fairly unsettled but unimpactful 2nd half of the week is
expected, with cooler temperatures and scattered showers likely.

&&

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

The initial push of light to moderate rain continues to spread
across the forecast area from southwest to northeast this
afternoon but we could see a little bit of a break/dry slotting
later in the afternoon or evening before the main wave pushes
through overnight/Monday morning. RAP soundings indicate that we
could see some pockets of MUCAPE around 100 J/kg or so tonight
and early Monday over coastal Maine and portions of the
interior. Thus, have included mention of isolated thunder here.

Rain should move out of the forecast area gradually from west to
east Monday late morning/early afternoon, but a few showers
could linger, especially in the mountains. Storm totals have
come in a bit higher in general across all of New Hampshire and
western Maine as we could see some heavier rain tonight into
Monday under convection, generally a half inch to an inch with
locally higher amounts possible along the coast.

Regarding temperatures, it will remain cool today with highs
mainly in the 50s. Tonight`s lows will mainly dip into the low
to mid 40s with a few upper 40s possible along the coast and a
few upper 30s in the mountains. Highs should recover nicely on
Monday, especially south of the mountains were we should see
widespread values in the mid 60s to the mid 70s. The mountains
will see highs in the mid 50s to the mid 60s. Monday night lows
are forecast to range from the upper 40s to the lower 50s.

KEY MESSAGE 2 DESCRIPTION...
Through the 2nd half of next week, a 500mb ridge builds in the
central US. The amplification of this ridge is likely to push an
upper-level low southward into the Canadian Maritimes. This will
allow for an unsettled and cooler end of next week.

Wednesday morning, a surface low moves southeastward across the
region. Instability exists with minimal energy and an early frontal
passage time should allow for more showery weather across the area
rather than thunderstorm activity. The cold front moves across by
the end of the day, allowing for even cooler temperatures to arrive
on Thursday. Temperatures on Wednesday will range from lower 70s in
the north, to low to mid 80s across southern NH.

Just like Wednesday, some instability may also exist on Thursday but
temperatures will be too cold to generate enough diurnal heating to
produce convection.  Thursday should start dry but become more
unsettled by the end of the day. Thus, more showery and rainy
weather is likely Thursday evening with rain chances a bit higher
over Maine. Showery conditions look to continue into the weekend.
High temperatures look to be in the mid-60s along the coast
through the remainder of the week, near 70F elsewhere.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
The full range of flight categories exists currently across the
forecast area as showers continue to slowly drift eastward. VFR
conditions still currently in place across eastern parts of the
forecast area as well as north of the mtns. While IFR and lower
CIGs and occasionally low VIS have crept into portions of
southeastern and central parts of the forecast area. The
general expectation is for that to expand up to the southeast
slopes of the mtns thru the overnight so that widespread IFR or
lower exists. Some fog may develop near the coast even as the
threat of showers diminishes overnight. I can`t rule out a
rumble of thunder as more rain/showers develop after midnight,
but confidence is low enough to not include in the TAFs at this
time. After that rainfall moves thru the area we will see
gradual improvement early to mid afternoon on Monday but some
MVFR CIGs will likely hang around. By late afternoon, most sites
should improve to VFR categories but some lingering MVFR is
possible in the mountains, potentially impacting HIE.

OUTLOOK:

Monday night: VFR conditions expected.

Tuesday: VFR conditions expected.

Tuesday night: MVFR possible in the mountains with showers and
isolated thunder.

Wednesday: MVFR possible due to showers and possible thunder.

Wednesday night: MVFR possible due to showers.

Thursday: MVFR possible due to showers, mainly in the mountains.

Thursday night: MVFR possible due to showers.

Friday: MVFR possible due to showers.

Friday night: MVFR possible due to showers.

&&

.MARINE...
High pressure continues its slow retreat today and southeast
or east southeast winds will slowly increase overnight into
Monday. While wind gusts will generally stay below 25 kt for
most of the waters, seas are forecast to build into the 5 to 7
foot range Monday. Current forecasts are for periods to be in
the high single digits, so seas may approach high surf advisory
criteria.

Generally relatively light winds are expected Tuesday through
the remainder of next week. Seas of 3-6ft are expected Tuesday
morning, but will decrease to 2-4ft by Wednesday morning. Seas
of 2-4ft expected beyond Wednesday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from 2 AM Monday to 8 AM EDT Tuesday for
     ANZ150-152-154.

&&

$$

DISCUSSION...Hargrove/Palmer
AVIATION...Legro