NWS Caribou, Maine Area Forecast Discussion
744
FXUS61 KCAR 271101
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
601 AM EST Sat Dec 27 2025
.SYNOPSIS...
High pressure will build across the region today through Sun.
Low pressure then lifts through the region Mon through Wed.
&&
.NEAR TERM /THROUGH SUNDAY/...
6 AM Update: Cold temperatures continue across the forecast
area, particularly where upper level cloud cover remains thin,
as many sites across the north have dropped to below 10 below
zero this morning. Upper level cloud cover will continue to
thicken over the next couple of hours, and limit surface heating
today, leading to cool temperatures.
Main Point:
* Cold air continues to hold onto the forecast area through the
weekend
A ridge of high pressure continues to shift eastward today,
while an inverted trough crosses the state into this afternoon,
bringing an increase in mid to upper level cloud cover over most
of the forecast area, though no precipitation is expected with
this trough. With this persistent cloud cover through peak
heating hours, temperatures will fail to warm much, with highs
only lifting into the lower teens in the north and upper teens
Downeast. Tonight, skies will clear as another high pressure
enters the northern New England region, and a deep nocturnal
inversion is expected to setup which will allow for efficient
radiational cooling and temperatures dropping into the lower
single digits above zero Downeast and potentially below zero
across the north.
Complicating the temperature forecast tonight will be a
deepening low pressure centered over Labrador, and the gradient
between this and the high pressure centered to our west
increases. This will lead to the development of an LLJ. Current
forecast profiles suggest that the nocturnal inversion will be
deep enough that even though winds will begin to increase late
in the night, efficient radiational cooling will still allow for
temperatures to quickly drop. However if this inversion fails to
hold, the return of mixing will keep temperatures on the warmer
side, albeit still below average for this time of the year with
lows above zero but still in the single digits to lower teens.
As winds increase near sunrise Sunday morning, wind chills may
drop into the teens below zero across the north, and approach
ten below zero Downeast.
Increased mixing heights on Sunday and a shift in air mass will
allow for high temperatures to lift into the 20s to around 30
across the forecast area. Breezy winds will continue however,
with wind chills remaining below 20 through the day, and leading
to another cold winter day.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Key Message...
1) Significant winter storm to bring mixed precipitation,
including sleet and freezing rain, Monday and Monday night.
Key Message 1...
Models have trended warmer for the significant weather system
Monday/Monday night, and we are looking at a very messy system
with all precipitation types in play. The primary surface low
pressure will be passing well north of us, but a very important
secondary surface low will be tracking from west to east through
our area. Models are in decent agreement on the timing and
amount of precipitation now, but there is still some uncertainty
on the track of this secondary low. It could track from west to
east as far north as Caribou, or it could be as far south as
Downeast. A more southerly track would keep the north mostly
snow, while a more northerly track would bring sleet and
freezing rain to the St John Valley. Going with a middle-of-the-
road approach for now, with broadbrushed mixed precipitation
over about the middle 3/4 of the area, with mostly rain along
the coast and mostly snow in the extreme north. This could
change obviously.
The onset of the precipitation from west to east should occur
Monday morning into early afternoon. The warm layer aloft comes
into play with or within a couple hours after the onset of
precipitation, and this means the likelihood of sleet or
freezing rain. With low-level winds likely to remain from the
east/northeast through Monday evening, with probably some degree
of cold air damming, this means that most areas W/NW/N of Bangor
and Lincoln will stay below freezing and be very slow to warm
while the warm air aloft moves in. Concerned enough about the
threat of sleet and freezing rain that we went unusually bold
for the likelihood of sleet/freezing rain this far out. One item
of good news is that this is a pretty quick-hitting system, with
about 12 hours of moderate precipitation of a half to three
quarters of an inch for most places. This means that while there
will probably be some decent sleet and freezing rain amounts
somewhere in the forecast area, it`s unlikely (but not
impossible) there will be enough ice to lead to tree damage.
While we can`t rule out over 6 inches of snow for some areas, if
this occurs, it would be in the far north, most likely north of
Presque Isle. As we head into Monday night, many areas
especially in the north will see a brief changeover back to snow
before the precipitation tapers off from west to east.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Key Messages...
1) Below average temperatures, potentially bitterly cold, Tuesday
night to Saturday.
2) Potential for more snowstorms mid to late week, but high
uncertainty
Key Message 1...
Colder air works in behind the Monday/Monday night storm, and
arrives in earnest Tuesday night. Below average temperatures are
very likely to continue into Saturday. Because of uncertainty
in timing/amplitude/strength of weather systems, there is
considerable uncertainty is temperatures from day to day mid to
late week. The cold end of model guidance is quite cold, though
(10th percentile of NBM MaxTs are around 0F in the north and
around 10F Downeast, and 10th percentile of NBM MinTs are around
-10F to -20F). Stayed with the deterministic NBM for
temperatures, which is still plenty cold with highs 10-15F in
the north and around 20F Downeast, and around 0F for lows in the
north and around 5 above Downeast.
Key Message 2...
Models are in poor agreement in the extended, but some
models/ensembles have one or possibly two systems Wednesday
night through Friday. If we do get any storms, they would be all
snow and on the light to moderate side rather than heavy.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR conditions will continue through today through
Sunday across all terminals. N to NW light winds around 5 to 10
kts today through tonight, increasing to 10 to 15 kts on Sunday
with gusts to 20 kts. NW LLWS around 40 kts likely to develop
around 00z tonight from KHUL northwards, and could spread
across the rest of the forecast area through the night tonight.
SHORT TERM:
Sunday night...Generally VFR. Occasional MVFR possible late. A
wintry mix possible late at KBGR/KBHB. Variable winds 5 to 10
knots.
Monday...VFR/MVFR early, lowering to IFR/LIFR through the
afternoon. Snow transitioning to a wintry mix north, with a
wintry mix transitioning to rain Downeast. Variable winds 5 to
10 knots, becoming east/southeast 10 to 15 knots with gusts up
to around 20 knots.
Monday night...IFR/LIFR. Snow, or a wintry mix transitioning to
snow, north. Rain transitioning to snow Downeast. East/southeast
winds 10 to 15 knots with gusts up to around 20 knots, becoming
west/southwest.
Tuesday...MVFR/IFR north with a chance of snow showers. VFR/MVFR
Downeast with a slight chance of snow showers. West/southwest
winds 10 to 15 knots with gusts up to 20 to 25 knots.
Tuesday night through Wednesday...VFR/MVFR with a slight chance
of snow showers north. VFR Downeast. Southwest winds 10 to 15
knots with gusts up to 20 to 25 knots.
&&
.MARINE...
NEAR TERM: Light N winds this morning will increase through the
day and shift NW, with gusts building to 25 to 30 kts this
afternoon. A small craft advisory is in place beginning at 4 PM
this afternoon. Seas will only build to 2 to 4 ft through this
time. SCA conditions will last into the day on Sunday, tapering
Sunday afternoon below advisory criteria. Light freezing spray
today through tonight, decreasing during the day on Sunday.
SHORT TERM: Westerly gales are very likely late Monday night
into Tuesday with seas to around 12 ft. The gales and high seas
could continue into Wednesday morning.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 2 PM EST
Sunday for ANZ050-051.
&&
$$
Near Term...AES
Short Term...TF
Long Term...TF
Aviation...AES/TF
Marine...AES/TF
NWS CAR Office Area Forecast Discussion
