NWS Caribou, Maine Area Forecast Discussion
568
FXUS61 KCAR 291106
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
606 AM EST Sat Nov 29 2025
.SYNOPSIS...
High pressure builds in through tonight, then exits to the east on
Sunday,as low pressure approaches from the west. A warm front
crosses Sunday evening, followed by a cold front crossing Maine late
Sunday night. A secondary cold front crosses the area on Monday,
followed by high pressure building in through Monday night. A
coastal low approaches from the south on Tuesday, passes offshore
Tuesday night, then exists into the southern Maritimes on
Wednesday.
&&
.NEAR TERM /THROUGH SUNDAY/...
6am Update...Minor changes were made with this update to reflect
the latest trends in observations and guidance. The forecast
appears on track.
Previous Discussion...
A northern stream shortwave passes this morning, followed by
northern stream shortwave ridging building in this afternoon.
High resolution guidance suggests any snow showers with the
shortwave should be confined to Northern Somerset county along
the border with Quebec, so pops have been adjusted accordingly.
Should see decreasing cloud cover, especially this afternoon
with the passage of the shortwave ridge. Highs today will range
from the upper 20s to upper 30s, this is a few degrees below
normal.
Deep layered ridging builds in tonight, with associated
subsidence keeping things dry. Should see increasing mid and
high clouds after midnight with the advection in of mid-high
level moisture ahead of the next system. The increase in cloud
cover makes the low temperature forecast a bit tricky, as it
should work to offset the winds becoming light and variable, if
not calm overnight. There is some question how thick these
clouds will be initially (especially if the ridge axis is a bit
slower to move off to the east) - so you could still end up with
some decent radiational cooling. To reflect this possibility
blended 2 parts NBM with 1 part NBM 10th percentile then
subtracting a degree for lows. If had full radiational cooling
would lean much more towards the NBM 10th percentile for lows.
As a result, expect lows to be from the lower teens to lower
20s, which is around 5 degrees below normal. With the winds
diminishing tonight, there should be little if any in the way of
wind chill.
The axis of the deep layered ridge exits to the northeast Sunday
morning, allowing for precipitation to move in from SW to NE
ahead of the leading edge of a northern stream trough extending
down from a cutoff low over Hudson Bay. The precipitation should
increase in intensity in the afternoon, with a southeast
30-35KT 950mb and southwest 50-55KT 850mb jets over the area by
Sunday evening. The precipitation should start everywhere as
snow, except near/south of a Bangor to Wesley line where it
should start as a rain/snow mix. The increasing low level warm
advection, should bring the precipitation to along and south of
a Dover-Foxcroft to Howland to Topsfield line, a mix of rain and
snow north of there to south of a Houlton to Katahdin to
Moosehead Lake line with all snow from there on north. By
evening expect 1-3 inches of snow along/north of a Monson to
Millinocket to Hodgdon line.
The increasing low level winds should bring about gusty winds in
the afternoon as well, especially in areas that have gone to
all rain. So expect 35-40mph wind gusts over coastal Downeast by
late Sunday afternoon, gusts up to 20-25 mph for the Bangor
region and northern Downeast Maine, with little in the way of
gusts farther north. For now not quite confident in exactly how
much winds mix down, so have held off on a Wind Advisory for
coastal Downeast at this time. Highs on Sunday should be near
to slightly above normal across the North and around 5 degrees
above normal elsewhere.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Key Messages...
1. Wintry precipitation ends in the north Sunday evening
2. Easily the coldest air of the season so far Monday night
1. Precipitation ends quickly from west to east Sunday evening.
Sped up ending time just a bit based off model trends. Still
expecting warmer air to work up into far Northern Maine with a
brief change to rain, or at least mix of rain, before everything
ends by about midnight. Overall confidence in the system is
high, with the main item of uncertainty being how far north the
change to rain gets and whether it can make it to the St John
Valley. Don`t anticipate any sleet or freezing rain. For storm
total snow accumulations, adjusted totals down just a touch,
with 1-4 inches from Houlton, Millinocket, and Dover-Foxcroft
north, with the higher end of that 1-4 inch range generally
being over north/northwest portions of Northern Maine. May end
up reaching low end advisory criteria (4 inches) at a few
places, but don`t see it being widespread enough at this point
to issue any advisories. Breezy from the south with a few gusts
35-45 mph possible mainly near the coast Sunday evening, then
winds decreasing.
2. Slight cold advection begins later Sunday night, with stronger
cold advection Monday afternoon/evening as the coolest airmass
of the season so far arrives. May see some snow showers with the
cold advection during the day Monday, and went above NBM PoPs
in the north, going with about a 30 percent chance of snow
showers. Can`t totally rule out a couple snow squalls in the
north, but the threat doesn`t appear to be particularly high as
instability is pretty limited. Looks quite breezy Monday with
gusts 25-35 mph from the northwest. Winds ease Monday night as
high pressure moves in. Looks very cold, easily the coldest of
the season so far, with lows 5 below to 10 above in the north,
and 10-15 above Downeast.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Key Messages...
3. Potential significant winter storm Tuesday/Tuesday night, but
still substantial uncertainty
4. Very cold Thursday/Friday
3. Models have only come into slightly better agreement for the
potential major Tue/Tue night storm, and confidence is still
low. Models/ensembles continue to wobble, some shifting the low
pressure track south/drier with the 0z cycle, and others
shifting north. A more northerly track of the low closer to the
coast would mean a foot of snow for portions of our area that
could occur quite quickly, more likely central or Downeast. A
more southerly track of the low further offshore means
precipitation could miss the area entirely. Averaging all the
current tracks brings the most likely snow over Downeast with
the potential for over 6 inches, but this is just an average,
and reality likely won`t match this average. Bottom line is we
need to be patient but continue to watch this system closely, as
it has the potential to be a big one.
4. Models have come into better agreement on an Arctic front passing
through roughly early Thursday, with very cold air behind it,
even colder than what we will be seeing late Monday/Monday
night. Snow showers or even snow squalls are a possibility
Thursday with the Arctic front. Toward Friday, the consensus is
for high temperatures only 15-20 in the north, but there`s a
realistic chance for highs to be closer to 10 in the north. Wind
chills Thursday night should be below zero, perhaps even as
cold as 20 below for some colder spots.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: Ceilings should flirt right below/above 3000ft this
morning, otherwise it should be VFR through the TAF period.
Winds becoming W 10-1520-25KT this morning. Wind gusts should
abate by early this evening, with the winds becoming light and
variable as the evening persists.
Sunday...VFR in the morning, becoming IFR or lower from SW to NE
in the afternoon. SE winds G15-25KT possible in the morning.
LLWS likely in the afternoon with a low end chance of SE winds
G30-35KT in the afternoon at KBGR/KBHB.
SHORT TERM:
Sunday night...IFR or lower Sunday evening, with snow or rain
from PQI north, and rain from HUL south to the coast.
Precipitation ends by about 6z, though IFR or lower is likely to
continue through the night. S winds 10-20 kts in the evening
with gusts 20-30 kts, strongest winds BHB/BGR, becoming SW 5-15
kts after midnight. LLWS likely.
Monday...VFR, except possible MVFR north. NW wind gusting 20-30 kts.
Monday Night...VFR with light wind.
Tuesday and Tuesday Night...MVFR or lower possible in snow,
especially south. Confidence is increasing, but confidence in
the details of this event, including location, is still low.
N/NE wind 10-20 kts possible if the storm takes a snowier track.
Wednesday...Probably VFR with NW winds 10-15 kts.
&&
.MARINE...
NEAR TERM: Gales in the coastal ocean waters are marginal in
nature and confined to the area 20-25nm offshore, but since the
gale warning is up, will allow to continue through 6 pm. The
winds in the coastal ocean zones should then become SCA level by
this evening. The intra-coastal waters should see SCA conditions
continue through this evening, so have extended the SCA there
through midnight tonight. Do expect all waters to see sub-SCA
conditions after midnight. Winds ramp back up on Sunday, with
gale conditions likely on all waters in the afternoon.
With the existing gale warning up, will hold off in hoisting
the gale warnings for Sunday, until the current one expires or
is cancelled.
SHORT TERM:
Gales expected (greater than 90 percent chance) late
Sunday through Monday morning, from the south at first, then
switching to the west. Seas to around 10 ft. Much improved
winds/seas Monday night/early Tuesday, but about a 50 percent
chance of gales late Tuesday night/early Wednesday from a
possible Nor`easter. Seas could also build back up to around 10
ft, depending on the track of the Nor`easter.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Gale Warning until 6 PM EST this evening for ANZ050-051.
Small Craft Advisory until midnight EST tonight for ANZ052.
&&
$$
Near Term...PM
Short Term...TF
Long Term...TF
Aviation...PM/TF
Marine...PM/TF