NWS Caribou, Maine Area Forecast Discussion
323
FXUS61 KCAR 010709
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
209 AM EST Thu Jan 1 2026
.SYNOPSIS...
A coastal low develops near the Maine coast this morning, tracking
into New Brunswick by evening, then slowly lifts north into the
western Maritimes through Friday night. Weak high pressure builds in
for the weekend as a weak coastal system passes to the south.
Canadian high pressure builds in Sunday night and Monday.
&&
.NEAR TERM /THROUGH FRIDAY/...
Key Messages...
1) New Years Day Winter Storm impacting Travel for Eastern Areas
2) Gusty Wind Behind System leading to frigid temperatures
Key Message 1...
This continues to be a challenging forecast with continued
model guidance differences less than a few hours out of
precipitation start times. The main driver is a potent shortwave
diving south out of Ontario towards New York State this
morning. Surface low pressure is located over upstate New York
based on latest water vapor imagery and Nighttime Microphysics
RGB helps confirm this location. Upper level divergence is
increasing off the southern New England coastline near Long
Island at this update. This is giving way to surface convergence
as the parent low develops on the leading edge of the 500mb
shortwave. Regional radars and ground observations shows
precipitation breaking out over Southern New England and over
the Gulf of Maine. This will increase to the Downeast Coast over
the next 1-2hrs as increasing moisture advection takes shape.
The 500mb trof will approach western New England by 12z this
morning and begin tilting negatively as the parent low tracks to
the Maine/Quebec border. In response to the upper level
divergence setting up over the Gulf of Maine surface
cyclogenesiswill take shape as energy is transfered from the
parent low to the secondary low by mid morning today.
This is where uncertainty continues to remain with significant
differences in operational global runs, some of the hi-res CAMs
and other models like the HRRR and NBM blends. The secondary low
will intensify during the day, moving toward the Bay of Fundy
by late afternoon. The upper trof will significantly become
negatively tilted over CWA at the same time and which will help
to capture with a track close to our border with New Brunswick.
The uncertainty lies with a jet streak further south of the Gulf
of Maine that may accelerate the surface low ahead of the
shortwave which was depicted in the 00z ECMWF, Canadian, and to
a lesser extent 00z GFS and NAM. While the HRRR, WRF (ARW),
RRFS and Canadian HRDPS show a more likely capture. However,
very few show the significant grab northward along the border as
previous 12z and 18z GFS operational runs did. Latest
GFS/ECMWF/Canadian ensemble members shows some low pressure
locations to allow for warning level snows Downeast and to
lesser extent the advisory level snows further north and west.
The NBM 4.3 and 5.0 continue to blend in hi-res cams supporting
plenty of QPF for warning level snows Downeast and advisory
level snows north and west. This forecast will lean heavily
towards the HRRR consistency combined with NBM 5.0 probabilities
supporting the current winter weather headlines. The track and
capture of the low is important because 1) snow that will be
falling Downeast, specifically Washington County, will intensify
as low deepens near the entrance to the Bay of Fundy and 2) it
may bring a deformation zone to far northeastern parts of the
state in the evening.
For the snow falling over Downeast Maine this morning the snowfall
rates will approach 1 to 1.5 inches/hr as the surface low
intensifies. Snowfall amounts of 2-5 inches look to be possible
along the coast between 12 and 18z, including the Bar Harbor
area over toward Vanceboro. The bulk of the snow will fall today
for Downeast areas with amounts anywhere from 6-9 inches,
highest over far eastern Washington County. However, cannot rule
out rain mixing in near the Eastport area depending on how
quickly the surface low cuts inland so this may cut down some
on snow amounts along the Washington County coast east of
Whiting. Further to the north as low heads into New Brunswick
this evening, previous/latest guidance is showing signs of
possible FGEN forcing with a deformation band setting up along
the Maine/New Brunswick border. How far west that can extend
remains in question but model trends have increased with heavier
snow affecting far eastern Aroostook County during the evening
and overnight hours but confidence remains low to moderate on
this band. Much of this snow away from the coastline will be
light in fluffy as NBM 5.0 SLRs remain in the 18-21:1 ratio with
deep cold air in place in the column. Now, given all the
uncertainty cannot rule out that portions of the advisory may
need to be upgraded to a warning and/or extended in time,
especially with impacts from blowing snow which leads to Key
Message 2.
Key Message 2...
Surface low pressure heads toward the Maritimes late tonight
with increasing pressure gradient and strengthening low level
jet. Temperatures aloft will drop off quicker than surface
temps with mixing up to 900mb. Winds aloft look to range from
30-35kts. West winds will gust to 25-35 mph across the region
leading to patchy blowing snow. If snow is currently falling
over the northeast zones, gusty winds may bring widespread
blowing snow downwind of open areas. Air temperatures will be
falling to or slightly below zero across the entire CWA
overnight. Given the gusty winds the wind chills will be
widespread -20 to -15F for much of the Downeast, Bangor Region
into Southern Aroostook County. Central Highlands, Moosehead
Region, North Woods and portions of Northeast Aroostook county
will approach -25F or slightly below it which will fall into
Cold Weather Advisory criteria. However, opted to hold off on
issuing an advisory due to uncertainty on the strength of the
low as it deepens which ties into the first key message.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Closed low continues to lift into the NW Canadian Maritimes
Friday night, with the axis of its base crossing the area on
Saturday, followed by southwest flow aloft setting up Saturday
night. With limited moisture to play with it should be dry.
Continued low level cold advection will usher in the coldest
airmass of the season with lows Friday night around 10 degrees
below normal, highs on Saturday and lows Saturday night around
15 to 20 degrees below normal. The lows on Saturday night should
be below zero everywhere except for maybe coastal Downeast
Maine.
West winds gusting to 25-30 mph Friday night and Saturday
should produce wind chills from the teens to lower 20s below
zero across the North and and from around 0 to 10 below across
Downeast Maine and the Bangor/Penobscot Region late Friday
night/early Saturday morning. Winds fall of Saturday night, so
the coldest wind chills should be in the evening, generally 10
to 20 below across the North and 5 below to 5 above elsewhere,
then should generally be close to the air temperature late
Saturday night. There is still some uncertainty as to exactly
how cold lows get Friday night and how strong the winds will be,
so there is some potential for needing a cold weather advisory
across at least portions of the North late Friday night/early
Saturday morning. Will mention this threat in the HWO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A northern stream trough passes on Sunday. It could bring a few
snow showers to coastal Downeast, otherwise it should be dry.
The region is under northwest flow aloft Sunday night-Monday. It
should be dry.
A northern stream shortwave crosses the area Monday
night/Tuesday morning, bringing the threat for isolated to
scattered snow showers, with the best chance across Downeast
Maine.
Northern stream ridging then builds over New England into
Tuesday night, then exits to the east by early Wednesday. It
should be dry, except for possible some lingering snow showers
early across eastern Downeast Maine.
A northern stream trough moves from Central Ontario into Western
Quebec Wednesday, bringing with it the chance of some snow
across the North and snow mixing with or changing to rain
elsewhere.
It will remain much colder than normal Sunday-Monday night. The
coldest night should be Sunday night - with a cold weather
advisory possibly being needed across the North, with an even
lower chance of one being required over Bangor/Penobscot Region
and interior Downeast Maine. Temperatures should be below normal
on Tuesday (but not significantly below normal), near normal
Tuesday night, then above normal on Wednesday.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR becoming MVFR/IFR this morning with -SN
developing. IFR/LIFR today with -SN. Winds light and variable
becoming E-NE 5-10kt. Late day wind shift NW and increase
10-15kt with gusts up to 25kt. -SN will become -SHSN in the
evening then VCSH. NW winds 10-15kt gusts 20-30kt. BLSN/DRSN
expected a terms tomorrow night. Thu night returning to VFR
south and VFR/MVFR north. LLWS likely Thu night. Friday VFR
with W winds 10-15kt and gusts up to 25kt.
SHORT TERM:
Friday night: VFR. W winds G15-25KT possible.
Saturday: MVFR possible. W winds G15-20KT possible.
Saturday night: VFR KFVE/KCAR/KPQI; MVFR possible KHUL; and
MVFR or lower possible KBGR/KBHB. W winds G15-20KT possible in
the evening.
Sunday-Sunday night: MVFR or lower possible.
Monday: VFR. W-NW winds G15KT possible.
&&
.MARINE...
NEAR TERM: Winds rapidly increasing today in response to
developing storm system over the coastal waters. Gale Warning in
effect from 2PM this afternoon through 1PM Friday for the
coastal waters and 10AM EST Friday for the intra-coastal
Waters. West winds 20-35kt with gusts up to 45kt. Seas 6-9ft on
the coastal waters and 3-5ft on intra-coastal waters. Snow/rain
may reduce vsby at times today into this evening. Freezing spray
develops tonight as air temperatures quickly fall. Freezing
Spray Advisory in effect from 8PM EST this evening till 1PM
Friday. Sea surface water temperatures range 40-44F from the
Downeast coast out 25nm including Passamaquoddy and Penobscot
Bays.
SHORT TERM: Gales possible on the coastal ocean waters Friday
night, with SCA conditions likely on the intra-coastal waters.
SCA conditions then likely all waters Saturday, possibly
lingering into Saturday night on the coastal ocean waters. All
waters should see sub-SCA conditions on Sunday. SCA conditions
should then return to the coastal ocean waters from Sunday night
into Monday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory until midnight EST tonight for MEZ002-
005-006.
Winter Weather Advisory until 7 PM EST this evening for MEZ011-
015.
Winter Storm Warning until 7 PM EST this evening for MEZ016-
017-029-030-032.
MARINE...Gale Warning from 2 PM this afternoon to 1 PM EST Friday for
ANZ050-051.
Freezing Spray Advisory from 8 PM this evening to 1 PM EST
Friday for ANZ050>052.
Gale Warning from 2 PM this afternoon to 10 AM EST Friday for
ANZ052.
&&
$$
Near Term...JS
Short Term...PM
Long Term...PM
Aviation...JS/PM
Marine...JS/PM
NWS CAR Office Area Forecast Discussion
