NWS Caribou, Maine Area Forecast Discussion
183
FXUS61 KCAR 302357
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
757 PM EDT Mon Mar 30 2026
.WHAT HAS CHANGED...
Update for 00z aviation discussion
- Increased snow and sleet totals/reduced ice totals across the
North/and expanded areas with snow/sleet/freezing rain to
include interior Downeast Maine Tuesday night-Wednesday
- Extended SCA on the coastal ocean waters through 6PM Wednesday
- Confidence increasing in significant mixed wintry
precipitation in Northern Maine late Thursday through Friday.
The system has trended a bit warmer.
&&
.KEY MESSAGES...
1) Wintry mix expected to develop later Tuesday and Tuesday
night for at least the northern half of the forecast area, with
a threat for slick surfaces and travel difficulties into the
Wednesday morning commute.
2) Significant wintry precipitation late Thursday through Friday
night, especially north of Bangor. This could lead to
significant travel impacts from the Thursday PM commute through
both the AM and PM commutes Friday.
3) Yet again weather system is likely for Saturday
night/Sunday/Sunday night. This system could bring more
impactful freezing rain and sleet, with probably a change to
rain before it ends sometime Sunday night.
&&
.DISCUSSION...
KEY MESSAGE 1...
Wintry mix expected to develop later Tuesday and Tuesday night
for at least the northern half of the forecast area, with a
threat for slick surfaces and travel difficulties into the
Wednesday morning commute.
KEY MESSAGE 1 DESCRIPTION...
A northern stream shortwave trough tracks along the Canadian
Border from the Great Plains to the Saint Lawrence River Valley
Tuesday and Tuesday night, then into the Canadian Maritime
Provinces on Wednesday. At the surface, this will result in a
storm system tracking across the midwest Tuesday, to Near New
Hampshire/Vermont by Wednesday morning, then across the northern
Gulf of Maine to near eastern Nova Scotia by Wednesday evening.
This track is a little farther south than the 00z guidance and
as a result, the forecast has trended a little colder. The
precipitation should be in two waves - the first with a 700 mb
shortwave running out ahead of the main system should produce
mainly light snow across the North and light rain/snow
elsewhere, with limited, if any accumulations. The main
precipitation push is with the main storm system from Tuesday
night into Wednesday morning.
Based on this, here are the expected precipitation types/amounts
from north to south:
- Northern Aroostook: Mainly snow is expected, with some sleet
mixed in from time to time. While freezing rain cannot be
completely ruled out here, it no longer is likely. Looks like
about 3-5" of snow and sleet. Snow develops Tuesday afternoon
and should end by mid-Wednesday morning.
- A box from Northern Somerset on east to Southeast Aroostook
and then on south to Northern Washington County then back west
to the southern Central Highlands. This area will experience
the full wintry mix, with 1-3" of snow, around 1/4-1/2" of
sleet and from 0.1 to 0.3 inches of ice. The precipitation
begins as a snow/rain mix Tuesday morning, should go over to
all snow for a few hours late Tuesday, then quickly becomes a
wintry mix Tuesday evening, that should come to an end by
around midday Wednesday.
- The Bangor Region, northern Hancock, and Central Washington
County: Should see a rain/snow develop Tuesday morning,
possibly changing to all rain Tuesday afternoon. Enough cold
air pushes in Tuesday night on northeast surface flow, that
should see some freezing rain (and if the depth of the low
level cold pool is sufficient, possibly some sleet) Tuesday
evening, before the precipitation changes to all rain after
midnight. Should see up to an inch of snow and sleet, with up
to a few hundreths of an inch of ice. Based on this, have
expanded the winter weather advisory south into this region.
- Across coastal Downeast Maine, a mix of rain and snow is
possible at the start of precipitation Tuesday morning,
changing to all rain and remaining so until tapering off
Wednesday afternoon. Around 1/2 to 2/3 of an inch of rain is
expected. Note if the storm track shifts even 25 miles to the
south, this could bring the risk of freezing rain into at
least northern portions of the region. This possibility will
need to be monitored for.
There is still some uncertainty on exactly how fast the storm
will exit to the east. Because of this, did not change the end
times of any headlines for now. If confidence increases on the
end time of wintry precipitation being into Wednesday morning,
later shifts could extend the end time of the Advisories.
KEY MESSAGE 2...
Significant wintry precipitation late Thursday through Friday
night, especially north of Bangor. This could lead to
significant travel impacts from the Thursday PM commute through
both the AM and PM commutes Friday.
KEY MESSAGE 2 DESCRIPTION...
A very active weather pattern is place, with another storm on
track late Thursday to Friday night. There is still significant
uncertainty, but this mainly involves in the onset timing and
the exact location of various precipitation types. The exact
precipitation types will be determined by the low pressure track
and how far north/south it tracks as it moves east through the
area. A further north track means less cold air damming and
warmer precipitation types, while a further south low track
means more cold air damming and cooler precipitation types.
What we do know is that there is likely to be fairly substantial
precipitation, much of it in wintry form, with the potential for
not just snow vs rain, but also freezing rain and sleet. In
terms of precipitation totals for the whole storm, there looks
to be somewhere in the neighborhood of an inch of precipitation
(liquid equivalent) from about Millinocket north, and a bit less
south of Millinocket. Definitely plenty of moisture to work
with. There has definitely been a warming trend with the models,
with the general consensus now being mostly snow/sleet in the
extreme north (St John Valley), a mix of snow/sleet/freezing
rain from Caribou to Millinocket/Greenville, freezing rain
and/or rain around Bangor, and mostly rain on the coast. But to
emphasize, this is just the general consensus, and there is
still a lot of north/south variability in where these
precipitation types set up, probably about 100 miles north/south
uncertainty. Also it`s important to note that there is a bit of
general warming trend through the event as we head into Friday,
with some places probably going to a warmer precipitation type
(such as snow to sleet, sleet to freezing rain, freezing rain to
rain). That said, it isn`t a strong warm push, and we are
unlikely to see temperatures get much if any above freezing in
the far north even toward the end of the event. We also have
mentioned the uncertainty in onset time. Expanding on this, it
could start as early as around dawn Thursday, or it could start
as late as about midnight Thursday night. Tend to favor an onset
on the later side, but this is something we will need to
watch/revise as the time nears.
KEY MESSAGE 3...
Yet again weather system is likely for Saturday
night/Sunday/Sunday night. This system could bring more
impactful freezing rain and sleet, with probably a change to
rain before it ends sometime Sunday night.
KEY MESSAGE 3 DESCRIPTION...
Compared to the previous systems, this one for the latter part
of the weekend looks to be on the warmer side, with a low
pressure track generally being just north of us. That said, it
still appears to be cold enough for some impactful freezing
rain and/or sleet on the front side of the system Saturday night
or Sunday morning, especially in the north. Most areas are
likely to change to rain later Sunday before it ends.
Precipitation doesn`t appear to be quite as heavy with this
system as the Friday system, more in the range of a half inch
rather than around an inch. This also is likely to lead to this
system being less impactful than the Friday one.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Tonight...VFR all terminals. LLWS for the first few hours at
Downeast terminals 26040kt at FL020.
Tuesday...Downeast terminals drop to MVFR after 12z in RA at
BHB and RAPL at BGR, before dropping to IFR between 15-16z in
cigs and vsbys. RAPL likely to change to RA at BGR around 20z.
HUL drops to IFR vsbys by 15z in SN. Remainder of Aroostook
terminals should remain VFR in SN in the afternoon. Winds
become northeasterly around 5kts during the day.
Tuesday night: IFR or lower likely. Mainly Snow KFVE/KCAR/KPQI.
Snow to a wintry mix KHUL. A wintry mix to freezing rain to
rain at KBGR Tuesday night and rain at KBHB. NE-ENE winds
G15-20KT possible.
Wednesday...Becoming VFR by around midday. NE winds G15-20KT
possible at southern terminals.
Thursday...VFR early, with cigs falling towards MVFR/IFR
depending on storm onset timing. NE winds around 5 kts.
Thursday night - Fri night...Decreasing conditions to IFR/LIFR
in mixed precip types, and staying IFR/LIFR into Fri night.
Great uncertainty remains in precip type at each individual
terminal. Better chance at snow and sleet at northern terminals,
and rain/freezing rain at southern terminals, but this is
subject to change. E/SE winds 10 to 15 kts, becoming variable
Friday night.
Saturday...Generally VFR. NE wind 5-10 kts.
&&
.MARINE...
High resolution models, supported by observations no longer
suggest at least 2 hours of gusts to gale force this afternoon,
so no need for a short fused gale warning on the coastal ocean
waters. Instead it appears that SCA conditions should persist
through at least Wednesday afternoon on the coastal ocean
waters - even if the winds slacken below SCA levels, the seas
should remain solidly above SCA thresholds due to a persistent
swell. As a result, have extended the SCA on the coastal ocean
waters through 6 PM Wednesday. Kept the SCA as is on the intra-
coastal waters, expiring at 6AM on Tuesday. For now it appears
that gusts and seas should stay just below SCA levels there
Tuesday- Wednesday.
Conditions will trend upwards towards gales Tuesday night, then
winds decrease once more Wednesday night behind a cold front.
Seas 3 to 5 ft to increase towards 7 to 12 ft Tuesday night,
then gradually improve through the second half of the week.
E/NE winds at or just below small craft Wed night to Thu night,
then becoming S Fri and then switching to NE Sat and likely
remaining small craft with winds through this period. Seas 3-7
ft Wed night to Sat.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 6 PM Tuesday to 11 AM EDT
Wednesday for MEZ001>006-010-011-015>017-031-032.
MARINE...Small Craft Advisory until 6 PM EDT Wednesday for ANZ050-051.
Small Craft Advisory until 6 AM EDT Tuesday for ANZ052.
&&
$$
DISCUSSION...TF/PM
AVIATION...21/TF/PM
NWS CAR Office Area Forecast Discussion
