854
FXUS61 KCAR 171217
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
817 AM EDT Sun Aug 17 2025

.SYNOPSIS...
A cold front approaches from the northwest this morning, then
crosses Maine from northwest to southeast today. High pressure
then builds down from southern Canada through Monday night. The
high then moves southeast Tuesday through Tuesday night. A weak
trough of low pressure crosses the area Wednesday and Wednesday
night. High pressure builds toward the region Thursday.
&&

.NEAR TERM /THROUGH MONDAY/...
Update...
Updated near term aviation discussion.

Previous Discussion...
Today, mid-level trough with associated cold front moves
through Maine. Rain begins in the northwest this morning,
gradually pushing southeast. The best chance for thunderstorms
will be in the afternoon into evening, given diurnal heating
support. Could be some gusty winds during the day. Looking at
the HRRR, the best area of instability is central and Downeast
Maine, with some CAPE ranging from 500  1100 J/kg during the
afternoon. Low-level lapse rates are favorable, but mid-level
lapse rates are not impressive. Models do hint at an area of CIN
that could work against any developing storms. Signal for some
decent 0-6km shear ahead of the front as well. Bottom line
upfront is that there is a potential for some thunderstorms to
develop, primarily in central and Downeast Maine. There could be
an isolated strong thunderstorm in the afternoon Downeast, but
confidence is low. Looking at rain totals generally around half
an inch. Daytime highs in the 60s in the north, 70s in central
Maine, and 80s Downeast, based on the speed of the front.

Front crosses into the waters by tonight, bringing cooler
temperatures behind it. 850mb temperatures go from roughly
14C-16C, to around 1-3C behind the front. As a result, expecting
some seasonably chilly overnight lows, in the upper 30s in the
north and upper 40s Downeast. During the day on Monday, high
pressure builds in, leading to another sunny and dry day. High
temperatures in the upper 60s and mid 70s along the coast.
&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
High pressure will build across the region Monday night into
Tuesday night. Expect mostly clear skies Monday night, then
partly cloudy Tuesday/Tuesday night. An inverted surface trof
will extend toward western portions of the forecast area Tuesday
night into Wednesday while an upper level trof crosses the
region. Expect partly sunny skies along with a chance of
showers Wednesday. Expect slightly below normal level
temperatures Tuesday/Wednesday. Low temperatures should fall
into the 30s across the normally colder locations of northern
Maine Monday night. Patchy frost is possible in the normally
coldest locations, mostly the favored northwest valley areas.
&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
Expect a chance of showers along with partly cloudy skies early
Wednesday night, with clouds and shower chances then decreasing
overnight. The upper level trof should help steer Hurricane Erin
out to sea, well southeast of the region, Thursday while high
pressure re-builds across the region. At this point, the primary
impact from Erin for the forecast area appears to be increasing
long period waves from Wednesday night into Friday which should
lead to hazardous beach conditions. Otherwise, expect
mostly/partly sunny skies Thursday. High pressure will bring
mostly sunny skies Friday. High pressure begins to move
southeast of the region Saturday, with a cold front possibly
starting to approach late. However, the timing of the cold front
is still uncertain. Generally expect mostly/partly sunny skies
Saturday. If a more rapid frontal timing verifies, could also
have a chance of afternoon showers/thunderstorms. Expect near
normal level temperatures Thursday through Saturday.
&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
NEAR TERM:
KFVE/KCAR/KPQI/KHUL: VFR/MVFR this morning through mid afternoon
with showers, possibly an isolated thunderstorm. Generally VFR
conditions then expected later this afternoon through Monday.
However, variable conditions possible with any patchy fog late
tonight. Variable winds 5 to 10 knots, becoming north/northwest
10 to 15 knots today. North/northwest winds 5 to 10 knots
tonight. North winds 10 to 15 knots with gusts up to 20 knots
Monday.

KBGR/KBHB: VFR/MVFR, local IFR/LIFR, this morning. VFR/MVFR
this afternoon and early evening with showers and
thunderstorms. Generally VFR conditions then expected later
this evening through Monday. However, variable conditions
possible with any patchy fog late tonight. Variable winds 5 to
10 knots, becoming north/northwest 10 to 15 knots later today.
North/northwest winds 5 to 10 knots tonight. North winds 10 to
15 knots with gusts up to 20 knots Monday.

SHORT TERM:

Monday night through Tuesday night...Variable conditions with
any patchy overnight mostly river valley fog. Otherwise, VFR.
Light and variable winds.

Wednesday...Generally VFR. A chance of showers. Variable winds
5 to 10 knots.

Wednesday night...Generally VFR. A chance of showers early.
Variable winds 5 to 10 knots.

Thursday...VFR. North/northeast winds 5 to 10 knots.
&&

.MARINE...
NEAR TERM: Winds and seas remain below Small Craft Advisory
conditions this weekend. Seas generally 4 ft or below over all
waters. Winds from the S/SW through the weekend, before shifting
to the N tonight. Wind gusts 15-20 kts possible. Potential for
some rain showers this evening into early Monday morning, and an
isolated thunderstorm is possible. Fog possible early this
morning.

SHORT TERM: Winds/seas below small craft advisory levels Monday
night through Tuesday night. Swells from Hurricane Erin will
begin to reach the waters later Wednesday with building seas
which will then persist into Friday leading to small craft
advisory conditions. A chance of showers Wednesday.
&&

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

&&

$$


Near Term...Brennan
Short Term...Norcross
Long Term...Norcross
Aviation...Brennan/Norcross
Marine...Brennan/Norcross