695
FXUS61 KGYX 111433
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1033 AM EDT Tue Mar 11 2025

.SYNOPSIS...
Mild and breezy today ahead of a cold front that will cross
northern New England tonight. High pressure builds in Wednesday
followed by weak system bringing chances for rain and snow
showers Wednesday night into Thursday. High pressure then
returns for the end of the week with temperatures rising above
normal Friday and Saturday. A frontal system approaches late in
the weekend bringing chances for widespread rain.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

10:30am Update... Adjusted temp trends slightly into the early
afternoon as temps have remained steady until the fog clears.
The fog is steadily lifting and dissipating from both south to
north, and from the coastline moving inland, with temperatures
quickly jumping into the 40s once the sun is out. This trend
should continue over the next few hours, still allowing temps to
warm into the 50s and 60s across most of the area today.



601 AM Update...Fog has developed across the
lower Merrimack Valley across SE NH into far SW Maine. Latest
mesoscale models suggest this fog will expand eastward over the
next couple of hours and have updated the forecast to account
for these trends.

Previously...

South to southwest winds will ramp up today ahead of an
approaching cold front that will cross the region tonight.
Temperatures at 925 mb will rise to around 10C to 12C and with
favorable mixing this will bring temperatures into the mid 50s
across much of the area with low to mid 60s across southern NH
and interior SW Maine. Winds will become gusty by late morning
with peak gusts around 25 to 30 mph. Skies will be partly to
mostly sunny with clouds increasing from the NW late in the day
as the cold front approaches.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
The cold front will approach the Canadian Border around sunset
and will bring chances for rain and mountain snow showers
through the first half of tonight. Latest mesoscale guidance
suggest shower activity will diminish as the front crosses the
coastal plain. The front will be offshore early Wednesday
morning with temperatures dropping into the teens and 20s for
lows.

High pressure builds in for Wednesday for mostly fair weather
and highs ranging from the 20s north to low 40s across the
south. A weak wave will approach from the west late Wednesday
for increasing clouds west to east Wednesday afternoon.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
04Z Long Term Update... Latest NBM suite of guidance shows
little change from the previous with a gradual moderating trend
thru the extended and the potential for moderate to heavy
rainfall Sunday night, along with gusty winds. A weak system
could bring some snow showers Wednesday night into early
Thursday but there are still plenty of ensemble members and
deterministic guidance that keeps us dry.

Previously...

The previously mentioned wave moves through Wednesday night and into
the first part of Thursday with potential increasing for a round of
light snow and slick travel for the Thurs. morning commute.
Ensemble probabilities from the GFS/ECMWF have approximately a 20-
40% chance of greater than an inch of snow for areas south of the
mountains with higher probabilities in the mountains. Probabilities
for more than 3" of are currently less than 10%, so confidence is
high that if snow does occur it will be a light event. Once the snow
ends, skies may stay mostly cloudy through the day with drizzle
possible. Temperatures may struggle to get out of the 30s if that
ends up being the case.

Surface high pressure slides east of the region Friday into
Saturday, allowing a warming trend with southerly flow returning.
A ridge of high pressure aloft is expected to keep things mostly dry
as well, but with increasing dewpoints there may be fog and low
clouds to contend with. Highs Friday expected to be in the 40s and
50s and even warmer by Saturday. However, the onshore flow will
likely keep coastal areas cooler.

There`s a strong signal in guidance toward the end of the forecast
period with an upper trough and cold front approaching the East
Coast. This will be the next chance at widespread precipitation
Sunday into Sunday night, and confidence is high enough in the track
of the low far enough north to where it will be warm enough for
mostly if not all rain. The majority of ensemble members at
this point support generally 0.50" to 0.75" of rain with a few
suggesting over an inch of rain possible locally. With
increasing dewpoints, there will probably be fog as well.
Snowmelt, ice movement, and rises in area rivers will all be
possible, and for more specific info, please refer to the
hydrology section below. Latest guidance is in good agreement
with the front clearing the first part of Monday, and should
this pan out, Monday will see a drying trend with breezy W/NW
winds and upslope showers in the mountains.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
Short Term...Fog has developed across SE NH that will bring
periods of LIFR/IFR at KPSM, KMHT, and KCON through sunrise.
Elsewhere mainly VFR through daybreak except cannot rule out
some low cigs and BR briefly moving into KPWM, KAUG, and KRKD.
SW winds will increase this morning with gusts to 20-25 kts
around mid day with mainly VFR into this evening. Mainly VFR
tonight into Wednesday, although some rain and snow showers and
low cigs could bring restrictions to KHIE tonight.


Long Term...Mainly VFR Wednesday night through Saturday,
although a low pressure could bring light snow and flight
restrictions Wednesday night into Thursday.

&&

.MARINE...
Short Term...South to southwest winds increase this morning
bringing SCA conditions to all waters into tonight. The front
crosses the waters Wednesday morning with NW winds gusting 25 to
30 kts. High pressure then builds in Wednesday allowing winds
and seas to drop below SCA thresholds.

Long Term...Conditions look to remain below SCA levels through
Saturday with flow returning to more southerly Saturday into
Sunday with the high sliding east ahead of a low pressure and
cold front that approach from the west on Sunday. Increasing
winds ahead of the front will likely bring a return to small
craft advisory conditions on Sunday, possibly gusts to gale
force, and these conditions may last into Monday behind the
front.

&&

.HYDROLOGY...
A controlled melt is likely this week as temperatures warm into
the 50s for much of the region, with runoff slowing at night as
temps fall below freezing. The slow release of the snowmelt
will keep river rises limited. River ice will likewise undergo
weakening through thermal rot, particularly in southern streams.
Attention turns to a dynamic storm system this weekend that
will spread rainfall over the region, resulting in more rapid
snowmelt late Sunday into Sunday night. There remains much
uncertainty in rainfall totals with the potential for over an
inch particularly in the south facing slopes of the White
Mountains. With gusty S winds and high dewpoints around 50 the
melt rate will accelerate over a ripened snowpack, with
snowmelt loss of 1-2" runoff possible. The combination of rain,
snowmelt and weakened river ice due to thermal rot, will cause
river rises sufficient to break-up and move river ice,
increasing the threat for ice jam flooding by Monday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 11 AM EDT Wednesday for ANZ150>154.

&&

$$


NEAR TERM...Clair
SHORT TERM...Schroeter
LONG TERM...Combs/Tubbs