NWS Caribou, Maine Area Forecast Discussion
666
FXUS61 KCAR 052341
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
741 PM EDT Sun Apr 5 2026
.WHAT HAS CHANGED...
- Updated aviation section to reflect 0Z TAFs
- Fire weather concerns mid-week with the greatest risk
Wednesday
&&
.KEY MESSAGES...
1) Heavy snow showers possible late tonight through Monday evening,
mainly in northern Maine. This may create slippery road
conditions.
2) Unseasonably cold temperatures expected Monday night and
Tuesday night
3) Low RHs expected Tuesday and Wednesday which may lead to
increased fire weather concerns
&&
.DISCUSSION...
KEY MESSAGE 1...Heavy snow showers possible late tonight
through Monday evening, mainly in northern Maine. This may
create slippery road conditions.
KEY MESSAGE 1 DESCRIPTION...
Weak surface trough will be moving through late tonight.
bringing snow showers to northern areas. Soundings indicating
fairly steep lapse rates tonight and again during the day Monday
with CAPE values around 30 J/kg. Have confined isolated to sctd
snow showers to northern and central areas but cannot rule out
a flurry or two Downeast tomorrow afternoon. West winds will
increase during the day but not too concerned about snow squall
potential, as there will not be a well-defined boundary.
Cannot rule out a Laurentian plume in the wake of fropa over favored
areas of the North, specifically the North Woods down toward Mars
Hill. Boundary layer flow of around 300 to 310 degrees would bring
band of snow showers to these areas with snow accums of up to one
half inch. By midnight dry air works in to end snow showers.
KEY MESSAGE 2...Unseasonably cold temperatures expected Monday
night and Tuesday night.
KEY MESSAGE 2 DESCRIPTION...
A cold airmass will begin filling in behind the departing cold
front as high pressure builds in from the west. Temperatures are
currently expected to be about 10 to 15 degrees below normal.
The coldest night will be Tuesday night with some areas in the
North Woods region approaching 0 degrees. A weak pressure
gradient should prevent extreme radiational cooling but valleys
could see temperatures dip below guidance. The light winds will
also favor wind chills in the single digits over the north and
teens further south.
KEY MESSAGE 3...Low RHs expected Tuesday and Wednesday which may
lead to increased fire weather concerns
KEY MESSAGE 3 DESCRIPTION...
Low RHs, breezy winds, and mostly sunny skies may lead to some
increased fire weather concerns Tuesday and Wednesday with the
greatest risk Wednesday.
On Tuesday, high pressure building in from the west will result
in subsidence across the area with a mix of sun and clouds
allowing for mixing up to 800mb. With ample dry air aloft, this
is likely to result in dry conditions near the surface with RH
around 30%, especially in the Bangor region and Upper Penobscot
Valley. Questions still remain as to just how low RHs will drop
depending on if a weak clipper moving just offshore brings any
precipitation to southern areas. In this case, light snow and
clouds may prevent significant fire weather concerns.
High pressure slides to the south of Maine Wednesday resulting
in W/SW flow across the area under a strong subsidence inversion
with ample dry air aloft. Deep mixing up to 800mb combined with
mostly sunny skies, especially further south, should contribute
to very low RHs, likely below 30%. Winds will not be near Red Flag
criteria but will still be breezy with gusts up to 15 to 20 mph.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Tonight...IFR/LIFR early, improving to MVFR/VFR with the wind
shift to the west. S wind 5 to 10 kt early, becoming W around
midnight.
Monday...VFR, except periods of MVFR in scattered snow showers
at the Aroostook terminals. W wind 10 to 15 kt with G20kt
Monday night...MVFR cigs over Aroostook terminals with improvement
to VFR after midnight. VFR Downeast terminals. NW 5 to 10kt.
Tuesday to Tuesday night: Periods of MVFR or IFR possible
Downeast terminals with possible -SN, but low confidence. VFR at
northern terminals. NW winds 5 to 10 kts with gusts to 15 kts.
Wednesday: VFR strongly favored. W winds around 10 kts with
gusts to 20 kts, shifting to SW late.
Wednesday night: VFR. S winds 5 to 10 kts.
Thursday: VFR with a slight chance of MVFR at northern
terminals late. S winds 10 to 20 kts with gusts to 25 kts.
Thursday night...VFR south, MVFR likely north late. S winds 10
to 15 kts.
Friday...MVFR likely north with a chance of MVFR south. S winds
around 10 kts.
&&
.MARINE...
Seas will remain elevated above small craft levels tonight. As cold
front moves through late this evening expect west winds increase aoa
25kts by morning. SCA for all waters thru 18z Monday before
conditions drop below small craft levels through the remainder of
the period.
Below SCA conditions through Tuesday, then winds above SCA
criteria Tuesday night. Below SCA conditions Wednesday and
Wednesday night with SCA winds and seas returning Thursday and
continuing through Friday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 2 PM EDT Monday for ANZ050>052.
&&
$$
DISCUSSION...21/SM
AVIATION...21/TWD/SM
NWS CAR Office Area Forecast Discussion
