Hermon, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

111
FXUS61 KCAR 041717
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1217 PM EST Tue Mar 4 2025

.SYNOPSIS...
High pressure will remain to our south this afternoon and
tonight. A warm frontal will lift north across the region
tonight into Wednesday. Low pressure will approach Wednesday
night and cross the area Thursday. The low will continue into
the Maritimes Thursday night into Friday then lift into Labrador
on Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
1215 pm update...Weak shortwave and associated cold front moves
into the area today with snow showers...mostly later this
afternoon. The front stalls and then lifts as a warm front
tonight into Wednesday. The trick of the forecast is sequencing
the rising temperatures versus the arrival of precip from the
west on Wednesday. The concern is freezing rain...or at least
very slick roads as rain falls on surfaces that have largely
been frozen for the past two months. As it stands now, the worst
threat appears to be in the northern half of the forecast area
where surface temperatures will only slowly creep above freezing
on Wednesday and steadier precip is likely through the
afternoon.

Previous discussion...
High pressure will be anchored well off the East Coast today as
a flow of warmer and more moist air begins to circulate around
the high, up the east coast, into our region. This will produce
mostly cloudy conditions as a warm frontal boundary forms over
the area. Milder air lifting north will boost temperatures into
the 30s across the region. Some patchy snow showers may form in
the warm front across the north and west this afternoon as a
function of the warmer, moist air lifting up over the cooler air
near the surface.

High pressure will remain well off the East Coast tonight as
milder air continues to circulate north around the back side of
the high. This will continue to bring a chance for patchy light
snow over the north, and possibly sleet and light freezing
rain over central parts of the area late tonight along the warm
frontal boundary. The ground is chilled and frozen solid so any
liquid precipitation falling will easily freeze on surfaces.
Lows tonight will range from near freezing Downeast to the mid
20s over the far north.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Wednesday...
Warm front early Wednesday over south-central portions of the
area will lift north through the day, and moisture will
increase from the west with precipitation becoming steadier. The
surface freezing line will be near or just north of Bangor to
start Wednesday, and progress north to the St John Valley in the
afternoon. Above freezing temperatures aloft will be a bit
north of the surface freezing line through the day, meaning
there will be a corridor with the potential for light freezing
rain. Not expecting anything too significant, with totals
generally less than a tenth of an inch, with the best potential
over central portions of the area, and mainly in the morning. An
inch or two of snow is likely in the north. By sunset, the only
place cool enough for any snow will be the St John Valley, and
even there it will begin mixing with rain by sunset.

Wednesday Night...
Warm advection from the south continues, with temperatures above
freezing everywhere through the night. Steady rain areawide,
moderate at times especially later in the night. Increasing
south winds. Can`t rule out advisory-level southerly gusts of
45 mph late in the night mainly along the coast. Don`t think the
wind will be enough to be impactful except for perhaps very localized
issues. Fog, potentially dense, is a concern areawide with the
juicy southerly flow and above freezing temperatures and a wet,
ripe snowpack.

Thursday...
Southerly winds slacken from west to east through the day as
the low-level jet shifts into New Brunswick. The moderate rain
also becomes lighter through the day, though it still looks
moist and gloomy with some fog. Quite mild with highs in the mid
40s to low 50s. Could see some hydrology issues especially in
southern areas...see hydrology discussion below.

Thursday Night...
Cold front finally moves through from west to east through the
night. Light rain should persist into the evening, perhaps
changing to snow from west to east late as colder air moves in
behind the cold front. Some models have an inch or two of snow
late Thursday night/early Friday before the precip tapers off,
while others move the precip out before the cold air arrives.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Chance of snow showers in the north Friday, and mainly dry
Downeast. Breezy from the west behind the cold front. Cooler
with temperatures fairly steady in the mid 20s to mid 30s.

Seasonably cool temperatures expected to persist through the
weekend and into Monday. Most models keep things fairly quiet
with only a chance of snow showers off an on. However,
intermittent GFS runs and some of its ensembles have been
hinting at a decent Nor`easter around Sunday. Most solutions,
however, keep the system well to our south, and going with this
idea for now.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions across the area will drop to MVFR
across the north later this morning then MVFR Downeast this
evening. MVFR conditions overnight will drop to IFR in lowering
clouds. Winds light SSW today and tonight.

SHORT TERM:
Wednesday...IFR/LIFR. Freezing rain possible mainly in the
morning, with the best threat at GNR, MLT, and HUL. Becoming all
rain by 0z except perhaps rain/snow mix lingering until about 0z
at FVE. SE wind 5 to 15 kt. LLWS possible late.

Wednesday night...LIFR due to cigs and fog. South winds 10 to
20 kt with higher gusts. LLWS likely.

Thursday...Mainly IFR. S wind 10 to 20 kts decreasing to 5 to 10
kts in the afternoon.

Thursday night...Generally IFR due to cigs and rain, possibly
changing to snow late. Variable winds becoming NW 10 to 15 kts
late.

Friday...Cigs and vis trending up from IFR early morning towards
VFR by afternoon. Winds trending up with west winds gusting to
30 kt by midday.

Saturday...VFR south, with MVFR/VFR north. W winds 10-15 kts.

&&

.MARINE...
NEAR TERM: A SCA will be up today through this evening for SW
winds gusting up to 25 kt. Seas will build up to 5 ft today then
6 ft tonight over the offshore waters in response to the
southwesterly.

SHORT TERM: Two likely periods of gale force winds, the first
being a southerly gale late Wednesday evening through midday
Thursday, and the second being a NW gale Friday/Friday night.
Seas generally 5 ft or higher through the period, and as high as
about 12 feet Thursday.

&&

.HYDROLOGY...
Models are in strong agreement for a significant rain and
snowmelt event Wednesday through Thursday evening. General
model consensus showing higher probability of 1 to 2 inches of
rain falling onto a snowpack that is ripening in portions of
Downeast Maine into the southern Central Highlands. Latest
analysis from NOHRSC combined with surface observations shows a
snowpack of 4-10 inches with generally 0.75 to 2 inches of SWE
within that pack for Downeast Maine. Across the Central
Highlands the pack ranges from 7-14 inches with 2 to 4 inches of
SWE within the pack. Across northern Maine including the
Moosehead Region, the pack ranges from 10-25 inches with
isolated higher amounts up to 30-35 inches. The SWE values
across Northern Maine are generally 3 to 5 inches with isolated
higher amounts up to 8 inches.

NOHRSC analysis shows the snowpack temperature across Northern
Maine and the Central Highlands is quite cold and very unlikely
to melt much.  It will absorb any rainfall and compact.

Across interior and coastal Downeast Maine including the Bangor
region the snowpack is 28-32F which means the pack is near or
is "ripe". A ripe snowpack will discharge when rainfall falls
into the pack especially combined with prolonged T+Td >32F and
gusty warm winds, which are all expected. The ground is
completely frozen in these areas, and in some places 2 ft deep,
so no ground absorption will occur with this event. The
potential exists to completely discharge 0.75 to 2 inches of SWE
with total snowpack loss combining with the falling rainfall
creating significant runoff. Many of the rivers have solid ice
conditions with ice thickness varying between a few inches to a
foot or more.

Thermal/mechanical breakup of the ice is very possible in
Downeast areas resulting in the potential for ice jams. This is
supported by combined T/Td thawing degree hours reaching 700 to
1000 during the warm up. These values are well associated with
ice jams historically.

Across much of the Central Highlands and northern Maine there
is little or no threat of ice movement with this event. This is
also supported by combined T/Td thawing degree hours below
threshold commonly associated with ice break up.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 4 AM EST Wednesday for ANZ050>052.
     Gale Watch from Wednesday evening through Thursday afternoon
     for ANZ050>052.

&&

$$


Near Term...Bloomer/MCW
Short Term...Foisy
Long Term...Foisy
Aviation...Bloomer/MCW/Foisy
Marine...Bloomer/MCW/Foisy
Hydrology...