Area Forecast Discussion
Issued by NWS Portland, ME

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935
FXUS61 KGYX 101837
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
237 PM EDT Thu Sep 10 2026

.WHAT HAS CHANGED...
Confidence is increasing in radiational cooling bringing about
cold temperatures that may allow for a patchy frost overnight
Friday and early Saturday morning in the north.

&&

.KEY MESSAGES...
1. Gusty winds subside this evening, then dry weather
continues through Friday. Cold temperatures overnight Friday and
early Saturday morning may allow for patchy frost development in
northern zones.

2. Saturday will be dry but the next cold front will lead to
some low impact showers on Sunday. Mainly dry weather is then
expected once again to start the work week.

&&

.DISCUSSION...
KEY MESSAGE 1 DESCRIPTION...
The pressure gradient that is resulting in today`s gusty winds
relaxes tonight as the low pressure center continues eastward
over Atlantic Canada. Winds will subside, but enough of a breeze
may persist to keep valley fog from forming. This breeze along
with passing clouds are also likely to be enough to keep most
locations from decoupling tonight, but it will still be chilly.
Those north of the mountains should see temperatures fall into
the low to mid-40s, while the foothills and points south range
from the upper 40s to the mid-50s.

Upper level flow turns northwesterly Friday as troughing takes
hold over the area. There will also be a slight tightening of
the pressure gradient again as high pressure begins to build in
from the west, with northwesterly wind gusts only expected to be
around 20 mph this time around. The cooler airmass is going to
be apparent as high temperatures only climb into the low to
mid-60s north of the mountains, and into the low to mid-70s in
the south. High pressure begins to crest overhead Friday night,
so strong radiational cooling is all but guaranteed to bring
about a cold night. I tailored the forecast heavily toward MOS
guidance which handles these situations better than the NBM
which results in widespread mid to upper 30s north of the
mountains. A patchy frost is possible, but also isolated enough
that I don`t feel an advisory is warranted at this time.
However, anyone with sensitive plants or crops outside is going
to want to take precautions to keep them from harm. Valley fog
is also likely. South of the mountains temperatures are going to
fall into the low to mid-40s.

KEY MESSAGE 2 DESCRIPTION...

High pressure will start to slide off into the Atlantic on
Saturday as an upper level ridge axis moves overhead. These
conditions will lead to fair weather and highs mainly in the
70s.

We transition back into southwest flow aloft Saturday night as
the next trough/front starts to approach and clouds increase.
Warm air advection and cloud cover may lead to some relatively
warmer lows so did blend in a little bit of NBM90 to better
account for these trends. Lows will mainly range from the lower
50s north, to the mid/upper 50s along the Main Coast, and up to
the lower 60s across southern New Hampshire.

The next low to medium rain chances (20 to 50 percent) then
return to the forecast Sunday morning in the form of scattered
rain showers ahead of the cold front. Sunday`s rain continues to
appear low impact as NBM probabilities for a quarter inch of
rain or more only max out around 50 percent over southern New
Hampshire and far southwest Maine. Probabilities for a half inch
or more max out around 40 percent over the same area and only
10 to 20 percent for an inch or more. Thus, we shouldn`t see a
wash out. The better chance for showers shifts north Sunday
afternoon and into the evening along the cold front as it moves
into the forecast area. Some of the models are suggesting some
modest instability so a rumble or two of thunder is not out of
the question in the afternoon or early evening. Any lingering
showers will likely move out by early Monday.

Ridging then moves across the region, leading to mostly dry
conditions to start the work week but the next front will bring
more low impact precipitation chances mid to late week.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Through 18Z Friday...Wind gusts subside tonight with enough a
breeze remaining to hinder the development of widespread valley
fog. However, it can`t be completely ruled out at HIE and LEB if
winds do go calm for a period of time. VFR conditions continue
through Friday with northwesterly wind gusts 15-20 kts at most
terminals.

Outlook:

Friday night: IFR is anticipated at HIE and LEB as widespread
valley fog is likely to develop under calm conditions

Saturday: Mainly VFR. Valley fog possible at HIE and LEB
Saturday morning.

Sunday-Monday: Generally VFR, with MVFR possible in showers.

Tuesday: VFR expected.

&&

.MARINE...
SCA wind gusts and seas continue through this evening, but
subside tonight as the front moves offshore. High pressure than
begins to build over the waters keeping conditions below SCA
criteria through Friday. Wind direction will remain steady
offshore.

Fronts moving off the coast early next week and toward the
middle of the week may lead to some rough conditions, but this
will depend on their strength.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ150>154.

&&

$$

DISCUSSION...Baron/Hargrove