Area Forecast Discussion
Issued by NWS Portland, ME

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429
FXUS61 KGYX 051308
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
808 AM EST Fri Dec 5 2025

.SYNOPSIS...
A very cold day is on tap for today, especially this morning.
However, winds will be much lighter. High pressure will arrive
later today and more seasonable temperatures return Saturday. A
weak low pressure system may bring some light snow showers to
the coast on Saturday. High pressure builds in Sunday before
another low pressure system potentially affects our area Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
800 AM Update:
Quick update to expire the Cold Weather Advisory on
time. Winds will continue to diminish through the morning as we
warm.

Previously:
The center of high pressure moves across the forecast area
today from west to east. This will result in a cold day but
much less wind that what we have experienced in the last day or
so. Highs will be in the 20s at lower elevations and teens in
the mountains.

&&

.SHORT TERM /SATURDAY/...
Clouds will gradually increase from south to north tonight and
the result will be a less cold night.

Saturday looks perhaps somewhat interesting, especially for the
coastal plain and southeastern NH. Low pressure centers
positioned well to our northwest and southeast as well as two
weak high pressure systems centered to our northeast and
southwest. This results in a "col" in the SFC pressure pattern
which is a localized area of relatively weak lower pressure
along with weak SFC convergence and weak ascent. Some CAMs, the
HRRR especially, are picking up on this small feature and
bringing a period of light snow or snow showers to the coastal
plain of Maine and southeastern NH on Saturday. If this does
indeed verify then some light accumulations may be possible.
Several other pieces of guidance are not as bullish on this so
will stick with only chance PoPs for the time being.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Pattern Overview: Several disturbances look to cross the area
next week as an active pattern continues. There is no strong
signal currently for an overly impactful system, but trends are
going to be monitored closely.

Impacts and Key Messages:
*Several chances for wintry precipitation occur in the
 extended, but no significant weather impacts are expected at
 this time.
*Temperatures run below normal through much of the long term
 period, with very cold nights, returning to normal near the end
 of next week.

Details:
Saturday Night: A trough axis slides eastward off the coast
Saturday night. This brings any remaining shower activity to an
end except for upslope snow showers as flow transitions
northwesterly. Calm winds and clearing skies should allow for
some radiational cooling, but with a slightly warmer airmass
moving lows bottom out in the teens area wide.

Sunday and Monday: Dry weather should continue through the
daylight hours of Sunday with even the upslope showers coming to
an end in the morning as high pressure moves overhead and an
approaching trough transitions flow back south westerly. The
southwesterly flow makes for increasing clouds, but high
temperatures should still be able to climb into the low to
mid-30s south of the mountains, and into the 20s to the north.
Precipitation chances increase Sunday night as the next system
approaches and models have some surprising differences. They all
agree that low pressure moves through the area Sunday night
exiting of the coast Monday morning, however the ECMWF is the
outlier with the low remaining progressive and heading out to
sea with little fanfare. The GFS and Canadian deepen the low as
it exits off the coast and phases with a much sharper trough.
This increases QPF and hangs it around into much of Monday. This
is showing up in the ensemble suite with probabilities of
24-hour snowfall greater than 3 inches 30-40%, whereas the ECMWF
ensemble has 10-20% greater than 1 inch. We are talking about
sub-advisory numbers here, but this bears watching as
uncertainty like this on day 3/4 raises an eyebrow. High
pressure builds in for a dry Monday night.

Tuesday-Thursday: The daylight hours of Tuesday are dry outside
of the mountains as high pressure remains nosed it through the
morning. Zonal flow aloft supports snow showers in the
mountains. The Tuesday night clipper remains up in the air as
the ECMWF ensembles remain tightly clustered on an inside runner
near the International Border that would bring light snow to
the area. The GFS ensembles are clustered further to the north
and west with no forcing aloft, making for a dry deterministic
run. The models seem to be in better agreement on a Wednesday
night/Thursday system, but still differ greatly on its track.
The GFS suite remains the warm solution with a more dominate
inland low pressure, and the ECMWF remains the colder solution
with a cluster near the benchmark. It should be noted that the
ECMWF also has a second cluster further south as well, so we
just continue to note these trends as we look ahead to an active
week.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR conditions will be the rule today and tonight
as high pressure slides overhead. Winds will be much lighter
too. MVFR conditions is light snow or snow showers are possible
on Saturday, mainly in the coastal plain.

Long Term...VFR prevails during the day Sunday, but toward the
evening is when ceilings lower to MVFR ahead of an approaching
system. This system may bring widespread snow to the region so
IFR or lower restrictions are possible Wednesday night.
Conditions improve back to VFR for Monday and Tuesday with the
next chance for restrictions being Tuesday night if another
system develops.

&&

.MARINE...
Short Term...Winds and seas rapidly subside early this morning
with conditions likely below SCA much of today through
Saturday.

Long Term...Conditions remain below SCA criteria through Sunday
before low pressure moving off the coast ramps up winds Monday
with marginal seas. Winds and seas briefly fall below SCA
criteria during the day Tuesday, but another system quickly
brings them back Tuesday night. This trend of a calmer day and
SCA night continue through Wednesday. After, a potential strong
coastal low builds seas above SCA criteria.

&&

.CLIMATE...
This air mass this morning will be anomalously cold and low
temperatures will approach records. This will especially be true
at PWM where the forecast is 5 degrees and the current record
is 7 in both 1989 and 1945. The forecast at AUG is 3 degrees
and the current record is 4 set in both 1989 and 1991.

&&

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

&&

$$

NEAR TERM...Ekster/Hargrove
SHORT TERM...Ekster
LONG TERM...Baron