Hermon, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

122
FXUS61 KCAR 201823
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
223 PM EDT Sun Jul 20 2025

.SYNOPSIS...
High pressure will crest over the area Tuesday, then continue south
of the region on Wednesday. A cold front will approach the area
Thursday into Friday.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
Sfc low located over swrn Maine with boundary over interior
Downeast, whether a sea breeze boundary or strengthened from outflow
from shower acrs the north. Some peeks of sun over our outer islands
and along our coastline this afternoon with 500 J over the MDI area
and over the North Woods per SPC mesoanalysis. Watching a line of
convection along the boundary back in GYX`s radar and it appears
that storms are building/diving to the south where better
instability is. Cannot rule out thunder over Downeast this afternoon
though most should remain elevated. With juicy airmass remaining and
pw values up near 1.60 inches, per GYX 16z sounding, biggest impact
continues to be locally heavy rainfall with any storms.

Across the north cold front is draped along the St. Lawrence and
continues to push south. Scattered showers occurring ahead of
it with line of convection over Quebec. Line of convection is
still pretty isolated and have little confidence in getting
better organized as it drops into CWA late this afternoon/early
this evening.

Cold front moves through the area and offshore after midnight
tonight. Skies clear immediately behind it before stratocu moves in
over the north. Winds remain well-mixed in wake of the front with
min temps only dipping down to around 50 over the northwest and
around 60 on the coast.

Monday will start off with clouds under cold pool aloft before it
shifts east into Canada late in the afternoon. Cold air advection
will keep temps 10-15 degrees below normal. We will still be about 3-
5 degrees above our record min maxes but it will still be chilly for
the middle of July. Deep mixing up toward 800mb will bring northwest
winds gusting to between 25-30 mph in the higher terrain. Although
not widespread impactful at ground level, it will be at elevation so
not a good day to attempt smiting Katahdin.

Skies clear for Monday night as high pressure begins to build in
from the west though northwest winds will remain elevated. Mins on
Monday night will be a few degrees colder than prior night with m40s
over the northwest to lwr 50s along the coast.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
High pressure will control the weather over Northern
and Eastern Maine for Tuesday and Wednesday. This will result in
mostly sunny skies both days. High temperatures Tuesday will be a
bit milder than Monday, but still below normal for late July. A weak
upper-level disturbance will bring some more clouds Tuesday evening.
Skies clear out later Tuesday night into Wednesday morning. How
quickly this occurs will have implications for low temperatures
Tuesday night. Currently forecasting low temperatures in the 40s in
northern valleys, with lower to mid 50s elsewhere. Given light
winds Tuesday night, these temperatures could end up several
degrees lower if skies clear quicker than expected. Return flow
begins to set up in the wake of the high on Wednesday. This will
allow high temperatures to return closer to normal. Some warmer
spots could reach 80 degrees on Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
High pressure continues to retreat eastward Wednesday
night into Thursday, while a cold front approaches from the
northwest. This will result in dew point temperatures rising into
the 60s by Thursday. Shower and thunderstorm threat Thursday
afternoon should be mainly confined to northern areas. This is due
to the position of the front and onshore southerly flow. More
widespread showers and thunderstorms likely Friday as the front
passes through. Uncertainty exists regarding the timing of the front
and the development of a wave of low pressure along it. Thus,
continued to lean on NBM guidance for PoPs during that time. Drier
and less humid weather returns behind the front for the weekend.
However, temperatures are not expected to be as cool as early this
week.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: Mostly VFR expected for n northern Aroostook
terminals this afternoon and evening. Can`t rule out a brief
MVFR cigs in showers this evening and low-level stratocu moving
in tonight but confidence is too low to include in forecast.

KHUL should see MVFR cigs for the next 3-5 hours as showers pass
over the terminal.

Downeast terminals at IFR/MVFR restrictions this afternoon as
showers move east toward the area. Cannot rule out tstms impacting
each site this evening. BGR briefly improves to VFR behind showers
before dropping toward IFR after 03z tonight, improving shortly
after cold frontal passage.

BHB drops to IFR after 00z tonight, possibly dropping to LIFR after
05z before becoming VFR after cold frontal passage.

Monday night will see all terminals at VFR conditions with NW
winds between 5-10kts.

SHORT TERM:
Tuesday & Tuesday Night...VFR. NW wind 5-10 kts, becoming light
and variable Tuesday night.

Wednesday...VFR. Light and variable winds, becoming S-SW 5-10 kts.

Wednesday night...VFR dropping to MVFR north, and possibly MVFR or
IFR over the south very late with BCFG. S-SW winds 5-10 kts.

Thursday...MVFR or IFR early with BCFG, improving to VFR south.
MVFR north in the PM with VCSH and isolated TS. SW winds 5-15 kts.

Thursday Night & Friday...MVFR/IFR with VCSH and isolated TS.
BCFG possible south Thursday night & Friday AM. SW winds 5-10
kts Thursday night, becoming W Friday.

&&

.MARINE...
NEAR TERM: Thunderstorms expected to move offshore early this evening
before coming to an end late this evening. Cold front moves over the
waters by midnight. Northwest winds will remain well-mixed behind
the cold front with gusts toward 20kts over the waters in the
afternoon. Seas will range between 1 to 3 feet through Monday
night.

SHORT TERM: Winds and seas remain below Small Craft Advisory levels
through early Thursday. Winds and wave heights build to borderline
SCA criteria late Thursday into early Friday on the outer waters,
before subsiding late Friday. Patchy fog could reduce visibility
over the waters Thursday. Isolated thunderstorms possible over the
waters Friday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.

&&

$$


Near Term...Buster
Short Term...Clark
Long Term...Clark
Aviation...Buster/Clark
Marine...Buster/Clark