NWS Caribou, Maine Area Forecast Discussion
182
FXUS61 KCAR 042339
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
639 PM EST Sun Jan 4 2026
.SYNOPSIS...
High pressure builds into the area through Monday. The high exits
east Monday night, followed by a weak low passing to the south on
Tuesday. Another low approaches from the west Tuesday night, moves
near the Maine coast on Wednesday, then exits over the Maritimes
through Thursday. Another low approaches from the west on
Friday.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
620pm Update...
Actually an extraordinarily difficult forecast tonight for sky
cover and temperatures. We have a strong inversion aloft from
about 850mb to 725mb that is capping the altostratus clouds and
locking them in place. Models are virtually all doing terribly
at capturing the inversion and thus the clouds, and most models
have us clear/mostly clear when in fact it`s cloudy north of
Bangor with clouds spreading south and probably getting into
more areas this evening. The question is whether or not these
clouds can dissipate and allow us to cool off, or will they
persist all night and make for a much less cold night than
anticipated. Think that clouds will persist at least through
midnight, and raised temperatures/sky cover especially over the
north to about 2am. However, still banking on some clearing
late in the night that will allow temperatures to plummet, and
left temps/sky alone after 2am. Another factor is a bit of a NW
wind just off the surface (more than was present this morning)
that will allow hilltops to not cool off too readily anyway, and
that should limit any frigid 20 below or colder temperatures to
valleys.
Key Message:
* Very cold temperatures tonight falling to 20 to 30 below zero
across the north, and to around 10 below zero in the Bangor
and Downeast regions.
Discussion:
High pressure gradually shifts eastward through the night
tonight, relaxing the pressure gradient aloft and allowing for
surface decoupling overnight. Clear skies will allow for
effective radiational cooling as temperatures plummet at least
as cold as the previous night, with lows at least to 20 below
over most of the North Woods up through the St John Valley, and
potentially making a run for 30 below zero, especially in
protected river valleys which may decouple earlier.
High pressure will slowly shift eastward through the day on
Monday, though arctic air will remain in the area with highs
only in the single digits above zero in the north and lower
teens Downeast. Monday night a low pressure system will begin to
approach the area, with a tightening of the pressure gradient
for a slight increase in winds as well as cloud cover, limiting
surface decoupling threat and allowing for temperatures to be a
little warmer, around 10 below in the north and single digits
above zero Downeast.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Key Messages
-Warmer temperatures move in Tuesday and Wednesday
-Low pressure system moves across the south Tuesday night and
Wednesday
For Tuesday, the upper level trof moving out of the region
should allow the warmer airmass from the south to move in.
Increasing clouds and warmer air should push temps into the mid
to upper teens in the north and 20s in the south. The main
concern will be the system moving into New England Tuesday night
through Wednesday.
For the ensemble models, this looks to be another day of
inconsistent runs. So far, there has been a trend of a further
south track over the waters for the European ensemble models
with some members more aggressive with the south track. In
addition, the European ensembles develop the center of the low
faster and have it exiting the waters by Wednesday afternoon.
However, the GFS, ECMWF, and CmC ensembles have a slower track
with the center of the low moving across the Downeast. Also, a
much slower exit of the low by Wednesday night.
The NBM seems to be a fairly good blend of the ensembles with
more snow in the north and rain in the south. As of this update,
the NBM shows very little mixed precip with the transition line
due to the slower warm air advection in the mid levels.
However, cannot rule out some sleet and/or freezing rain as the
warmer airmass moves northward with very little accumulation.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Key Messages
-Warming trend through the rest of the week
-Possible large low pressure system by the weekend
A large surface ridge should move into the region by Thursday,
bringing in the warmer airmass from the tropics and boosting
temps to above normal for the rest of the week. By Friday,
extended models show a large cold front moving through the
region. As of this update, models show the cold front attached
to the warm front of the next low pressure system moving across
the plains. This should keep temps above normal through the
weekend. This large low pressure system is shown to track NE
across the Great Lakes as an occlusion with a triple point over
New England. The ensembles show more agreement with a system
moving in, but the track and timing are very inconsistent.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
NEAR TERM: Mainly VFR conditions continue tonight through the
day on Monday and into Monday night. Some BKN-OVC ceilings
tonight at times, but these are generally around 5K AGL which
puts them in the VFR category. Can`t rule out a brief period of
MVFR cigs Monday evening mainly BHB/BGR. Light NW winds less
than 10 kts.
SHORT TERM: Tuesday-Tue night...VFR north, VFR/MVFR south in
snow showers. Light and variable winds.
Wednesday...MVFR/IFR in snow north and rain south. Variable
winds 5-10 kt.
Wed night-Thu night...VFR. WNW winds 5-10 kt. Then light S winds
Thu night.
Friday...MVFR/IFR in rain/snow. SSW winds 5-10 kts.
&&
.MARINE...
NEAR TERM: Winds may increase slightly overnight with wind gusts
to 25 kts on the coastal waters, and a small craft advisory is
in place through the night. Very cold air over the waters
combined with these winds will result in the threat for moderate
freezing spray as well. Winds diminish again Monday morning with
seas 1 to 2 ft Monday through Monday night.
SHORT TERM: Winds and seas should remain below SCA levels Tue
through Wed. Wed night could see SCA winds in the outer waters,
then decreasing Thu morning. Sea should remain SCA levels
through Thu. SCA winds return Fri afternoon.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Cold Weather Advisory until 9 AM EST Monday for MEZ001>004-010.
MARINE...Small Craft Advisory from 10 PM this evening to 10 AM EST
Monday for ANZ050-051.
Freezing Spray Advisory from 10 PM this evening to 10 AM EST
Monday for ANZ050>052.
&&
$$
Near Term...AES/TF
Short Term...ARL
Long Term...ARL
Aviation...AES/TF/ARL
Marine...AES/TF/ARL
NWS CAR Office Area Forecast Discussion
