NWS Caribou, Maine Area Forecast Discussion
784
FXUS61 KCAR 211031
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
631 AM EDT Sat Mar 21 2026
.WHAT HAS CHANGED...
630 am update to aviation discussion
&&
.KEY MESSAGES...
1) A chance of heavy snow showers over the North this afternoon.
2) Snow event expected Sunday morning through Monday morning. The
highest totals will be Downeast with a dusting to an inch over
the far North.
3) Active weather pattern continues with another potential system
expected the end of next week. Temperatures will fall back below
normal for late March.
&&
.DISCUSSION...
KEY MESSAGE 1...A chance of heavy snow showers over the North
this afternoon
KEY MESSAGE 1 DESCRIPTION...
The modeled snow squall parameter for Saturday afternoon has
increased with each of the last several model runs. A deeper
dive into the thermodynamics and kinematics reveal some weak
instability of up to 50 J/kg, steep low-level lapse rates, and
strong winds in the mixed layer. The quality of each parameter
varies between models but is enough to raise the possibility of
a few heavy snow showers, mostly over the North Woods. Working
against any potential convection would be increasing 500mb
heights in the wake of a departing upper trough which will act
to suppress vertical motion.
KEY MESSAGE 2...Snow event expected Sunday morning through Monday
morning. The highest totals will be Downeast with a dusting to
an inch over the far North
KEY MESSAGE 2 DESCRIPTION... A weak upper level wave moving in
from the west early Sunday will result in precipitation
developing over the area in the morning with a stronger upstream
shortwave digging into New England Sunday night which will intensify
low pressure as it moves over the Gulf of Maine. Overall, there
is high confidence that the greatest totals will be found Downeast
with progressively lower totals further north. However, models are
uncertain regarding just how strong low pressure gets in the GoM
and if a clear secondary low can develop. A stronger low would favor
greater snowfall while a weaker one would favor less. Model soundings
Downeast show relatively warm temperatures in the low-levels
which in combination with surface temperatures at or just above
freezing should favor a wetter snow with SLRs of below 10 to 1.
Progressively drier snow expected further north in the cooler
air. This looks to be an all snow event as any low level warm
layer should be very shallow due to steep lapse rates. Cannot
completely rule out some rain briefly mixing in further south
depending on just how strong the warm air advection is.
KEY MESSAGE 3...Active weather pattern continues with another
potential system expected the end of next week. Temperatures
will fall back below normal for late March.
KEY MESSAGE 3 DESCRIPTION...
Southwest U.S. ridge continues to build, leaving H5 trough to
the east of the MS with multiple shortwaves bringing continued
chances for precipitation. Latest guidance is indicating that
the best chance for the next potential storm will be toward the
end of next week. At this time it appears a variety of precip
types will be possible over the region, with a rain/snow mix
over southern areas and mostly snow across the north.
Cold air will move into the area with 1035mb sfc high building into
the Prairie Provinces of Canada. Temps will be below normal
after the storm passes and into next weekend.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Today...Downeast terminals IFR early, improving to MVFR by mid-
morning and then VFR this afternoon. Northern terminals should
improve to MVFR by about 16z but some lingering snow showers
could produce occasional MVFR throughout the day. Light and
variable winds becoming N/NW at 10 to 15 kts this afternoon.
Tonight...VFR. Some lingering snow showers possible early at
CAR/PQI/FVE. Light N/NW winds around 5 kts.
Sunday...Conditions deteriorate to IFR at southern terminals by
approximately 16z. MVFR/IFR at northern terminals generally after
16z with the best chance of IFR at HUL. Snow at all terminals
with the heaviest snow south. E winds 5 to 10 kts.
Sunday night-Monday...MVFR/IFR north with IFR or lower Downeast
terminals. NE 5-10kts becoming N 5-15kts Monday morning.
Monday night-Tuesday...Mainly VFR. NW 5-15kts.
Tuesday night...VFR early, becoming MVFR/IFR late in snow. SSW 5-
15kts.
Wednesday...MVFR/IFR in snow. WNW 5-15kts with gusts 20kts in the
afternoon.
&&
.MARINE...
Small craft conditions continue over all waters until this
evening for the intracoastal waters and until a little after
midnight tonight for the coastal waters. Small craft conditions
return early Sunday afternoon as winds increase above criteria.
Small craft conditions over the outer waters Sunday evening with
gales possible Monday into Monday evening. Seas climb to above SCA
levels Sunday night and max out between 5 to 8 feet Monday night.
Conditions drop below SCA levels briefly on Tuesday before climbing
above late Tuesday night with another potential for gales on
Wednesday morning.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for ANZ050-051.
Small Craft Advisory until 5 PM EDT this afternoon for ANZ052.
&&
$$
DISCUSSION...21/SM
AVIATION...21/SM
NWS CAR Office Area Forecast Discussion
