062
FXUS61 KCAR 190707
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
307 AM EDT Thu Jun 19 2025

.SYNOPSIS...
Low pressure will approach from the west today...track along the
northern edge of our area tonight...then continue east into the
Maritimes on Friday. High pressure will return on Saturday. A
very warm ridge of high pressure will begin to build to our
southwest Sunday into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Low pressure will approach from the west today. Ahead of the
low, a humid airmass across the area will result in low stratus
clouds and some fog early this morning. The fog may be dense in
some areas near the coast where the humid air is moving in over
the colder ocean waters. As the low continues to approach this
afternoon aiming to track along the northern edge of our region,
showers and some embedded thunderstorms will form over the far
north supported by developing surface convergence. Some
additional thunderstorms will form along a trailing cold front
across the western edge of our region late this afternoon. CAPES
over the west are up to 2000 J/KG with moderate shear and very
high moisture. Thunderstorms across the west have the potential
to be strong including gusty winds, hail and torrential
downpours in some areas. The storms will track east from there.
However, the convection will encounter a more stable airmass to
the east where a relatively cooler marine layer is advecting up
from the south. The potential still exists for some heavy
downpours and frequent lightning mainly as a function of
elevated convection. However, the chances for severe storms
will diminish as the surface base cape is lost. Some showers and
embedded thunderstorms will continue across the north overnight
supported by surface convergence and some residual buoyancy
from cooler air moving in aloft. Further south it will remain
mostly cloudy with some low clouds and a chance for showers.
Recapping the risks: Chances for severe thunderstorms including
hail and high winds will mainly be across the west. Flash flood
risks may be throughout the northern half of our area with
highest chances from north central areas on west. Timing for
potentially impactful storms will be late this afternoon into
this evening.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Friday...
A fairly strong upper trough and associated surface low pressure
will be moving from SW to NE through the area on Friday. The
best dynamics will be over the north, with the surface low
tracking SW to NE through the Crown of Maine early Friday. Out
ahead of the low, we will still be in the warmer/muggier airmass
with the potential for storms from the morning to about mid-
afternoon over N/NE portions of the area. Don`t anticipate
anything strong/severe as instability and shear aren`t
impressive. In the afternoon, cooler air rushes in from the west
along with a gusty westerly wind. Showers should continue
through the afternoon in the north, with much smaller chances in
the south toward Bangor and Downeast.

Friday Night...
Any remaining showers in the N/NE taper off in the evening,
with decreasing clouds through the night. Cooler and breezy,
with lows in the 50s.

Saturday...
High pressure for Saturday with a very nice day. Mostly sunny,
highs in the mid 70s to around 80, and no more mugginess with
dewpoints in the mid 40s to low 50s.

Saturday Night...
Quiet in the evening. However, late Saturday night, most
models/ensembles have a shortwave trough and likely mesoscale
convective system (MCS) moving from WNW to ESE through some
portion of the Northeast. It could track through anywhere from
Northern Maine to far Northern Pennsylvania, so there is a lot
of N/S uncertainty. Definitely something to keep an eye on, and
have around a 40 percent chance of showers/storms late Saturday
night to account for this possibility.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The above-mentioned potential MCS should exit the region Sunday
morning, leaving a quiet late morning/afternoon. Highs around 80
and a bit muggier than Saturday, but not too bad.

Potential Heat Monday/Tuesday...
A very anomalous upper level ridge of high pressure builds to
our south, centered around the Mid-Atlantic down to TN/NC.
Typically, the warmest temperatures are to the north of the
center of the upper level high. While we are to the north, we
may be a bit too far north to get the most anomalous surface
temperatures. That said, it`s close and any little deviation
could mean big changes in temperatures. For now we are going for
highs Monday in the mid/upper 80s and highs Tuesday mid 80s to
low 90s. The warmest temperatures appear to be in interior
Downeast/Bangor Region up to Dover-Foxcroft and Lincoln. It
will be muggy, so if temperatures end up on the warmer side of
things, heat indices could top 100 in a few spots. Compared to
the June heat wave of last year when Caribou tied an all-time
high of 96F on June 19 with an all-time high heat index of 103F,
the upper level high center is a bit further south with this
heat wave, roughly 150-300 miles. Think that the highest
potential for really anomalous heat is just SW of our forecast
area, though the SW corner of our area such as around Bangor
will need to be watched especially closely. Of note, the
National Blend of Models (NBM`s) deterministic high temperatures
are running very much on the cool side of its probabilistic
distribution. We saw this with June 2024`s heat wave, and for
most areas, especially areas closer to the upper level high,
NBM`s deterministic high temperatures should be trusted more
than the NBM`s probabilistic distribution. This has to do with
different bias correction periods during the change of seasons,
and the longer bias correction period of the probabilistic
distribution brings its probabilistic temperatures too warm.
All this said, those using NBM`s temperature probabilities for
high temperatures for this heat wave should use extreme caution,
or better yet put more faith in the NBM`s deterministic
temperatures. Forecast is pretty close to NBM`s deterministic
temperatures.

Concern for Storms Monday/Tuesday...
Another concern for Monday and especially Tuesday is
thunderstorms. With us being on the north side of the upper
ridge with a very warm, juicy airmass, we will be in a
susceptible position for strong/severe storms. Tuesday looks
like the best shot at this point, but timing shortwaves moving
around the top of the upper level ridge is hard this far out.
Tentatively expecting some cooling/drying toward Wednesday.

&&

.AVIATION /04Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR to LIFR conditions in low clouds, and fog, are
expected today into tonight. Scattered thunderstorms will heavy
downpours possible over the north late today into this evening.

SHORT TERM:
Friday...BGR/BHB will potentially begin IFR/MVFR, but should
improve to VFR by midday. From HUL north, mix of MVFR/low VFR
with showers and potential thunderstorms. S/SW wind 10-15 kts
becoming W 15 kts with gusts to 25 kts from 18z on.

Friday night...VFR other than potential MVFR in the north early
evening. W/NW wind 10-15 kts decreasing to 5-10 kts.

Saturday...VFR. NW wind 5-10 kts.

Saturday night through Sunday...VFR, with a chance of MVFR.
Thunderstorms possible late Saturday night. Light/variable wind
becoming S 10 kts Sunday afternoon.

Sunday night through Monday...Generally VFR. S wind 5-15 kts.

&&

.MARINE...
NEAR TERM: Winds will remain below SCA today into most of
tonight then increase to SCA in SW winds late tonight. Seas up
to 2 ft today building to 4 ft tonight. Humid air over the
colder waters will result in fog, dense at times, today into
tonight.

SHORT TERM: Small craft winds/seas expected late tonight through
Friday night. Conditions then generally below small craft
Saturday through Monday. Possible fog early Friday, but then
improvement Friday night through the weekend.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Dense Fog Advisory until 8 AM EDT this morning for MEZ029-030.
MARINE...None.

&&

$$


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