-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 212348
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
748 PM EDT Sun Apr 21 2024

.SYNOPSIS...
A vigorous cold front will cross the area late tonight into
Monday morning. High pressure then crests over the region into
Monday afternoon, then slowly slides to the east into Tuesday.
Low pressure will approach Tuesday night, cross the area
Wednesday, then slowly exits into the Maritimes through
Thursday. High pressure builds in from the west for Friday.

&&

.NEAR TERM /THROUGH MONDAY/...
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750 pm update...
Strong cold front is dropping twd the St. Lawrence River this
evening with a line of broken showers along it. Expect these
will begin to move into nrn zones btwn 03z-04z tonight and grids
have this well accounted for. Only minor tweaks to temps and
dwpts with showers gradually diminishing in coverage after about
09z. Cold advection will allow what remains of showers to be
just lingering light snow showers late tonight.

Prev discussion blo...
A vigorous cold front will cross the area overnight tonight
with much colder modified arctic airmass. Tonight, expecting the
diurnal showers to weaken and dry up but surface lift induced
showers will kick off ahead of the front mainly impacting
northern areas with rain turning to snow. The best chance at a
dusting of snow will be across the Crown down to perhaps the
northern Baxter region. Temperatures tonight will crash behind
FROPA and fall back into the low to mid 20s across the north
with upper 20s to 32F in the Central Highlands and low 30s along
the coast. Tomorrow, a very dry airmass but cold airmass will
move in with temperatures struggling to recover during the day.
Skies will turn full sunshine but highs under strong cold air
advection will only top out in the low to mid 30s across the
north, low to mid 40s across southern areas given the NW
downslope winds off the Longfellow Mtns. NW winds will be gusty
20-30mph across the area. Relative humidity will be very dry in
the 20-25% range across the area. Given the winds, low RHs and
cold temperatures not entirely too worried about fire weather
but still needs to be monitored.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Monday Night...
Surface high pressure will be centered over the Gulf of Maine
Monday night. Skies will be mostly clear. Conditions aren`t
looking quite as good as they had been for a good radiational
cooling night, as there will be an increasing pressure gradient
through the night mainly in Northern Maine that could lessen the
decoupling. Still expecting cold temperatures...just not
terribly cold. Going for lows in the 20s, coolest in valleys.

Tuesday...
Surface high pressure moves off to the east and next system
begins to approach from the west. Still a good amount of sun.
Expect an increasing south breeze with gusts around 30 mph in
the afternoon. Much warmer than Monday as well, especially in
the north, with upper 50s in the north and low to mid 50s
Downeast. Relative humidities will be quite low in the afternoon,
mainly in the mid 20s to mid 30s, and coupled with the south
breeze, any fires that begin could get out of control in a
hurry.

Tuesday Night...
Clouds continue to increase from the west as the next system
approaches, with skies becoming cloudy. Most precipitation
should hold off until during the day Wednesday, though it could
begin to enter extreme NW Maine late in the night. Airmass
should be warm enough for rain at the onset late Tuesday night
in NW Maine.

Wednesday and Wednesday Night...
The main period of concern is Wednesday/Wednesday night. An
upper trough will be diving SE out of James Bay and cutting off
as a strong upper low as it moves roughly over Maine late
Wednesday. Much colder air will move in some time Wednesday
afternoon or evening as the upper low passes by. A surface low
may intensify just to our east Wednesday evening. Looking like a
very dynamic situation. There is still a good amount of model
uncertainty, but models are in a lot better agreement than they
were 24-48 hours ago and seem to be converging on an upper low
track and evolution of the system that is conducive for us to
get at least a little accumulating snow in the north. If this
happens, the rain would transition to snow from west to east
Wednesday afternoon and evening before tapering off later
Wednesday night or Thursday morning. It is a bit early to talk
accumulations, but totals over 3 inches are possible mainly over
the northern half of the area. Roads could also freeze Wednesday
night for some areas as the colder air moves in with roads
remaining wet when temperatures fall below freezing.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Blustery and cool Thursday as the system exits to our east.
Could be a few remaining rain/snow showers mainly in the north.
High pressure builds in Friday/Saturday with warmer temperatures
and dry conditions. Next rain chance comes around Sunday.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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NEAR TERM: VFR majority of the night, with an exception of 1-2
hours of MVFR cigs for northern terminals between 07-11z along
cold front. Winds will gust to between 25-30kts Monday afternoon.
Cannot rule out LLWS north of BGR overnight with speeds of
30-35kts.

SHORT TERM:
Monday Night through Tuesday Night...VFR. S winds 5 kts or less
Monday night, increasing to S 10-15 kts with gusts to 15-25 kts
Tuesday/Tuesday night.

Wednesday...Becoming IFR or worse areawide by the end of the
day in rain, possibly changing to snow late in the day PQI
north. Wind S 10-15 kts switching to the W late in the north.

Wednesday Night...Any remaining S winds switch to the W/NW 10-20
kts. Generally IFR in the evening with rain changing to snow,
possibly improving to VFR late especially BGR/BHB.

Thursday...Mainly VFR, though MVFR possible north in a few rain
and snow showers. NW wind 10-20 kts with higher gusts.

Thursday Night and Friday...W/NW 5-10 kts and VFR.
-- End Changed Discussion --

&&

.MARINE...
NEAR TERM: Tonight SW winds shift W generally less than 20kt.
Seas generally 2-4ft with a wave period of 6-7sec. Tomorrow AM
an Small Craft Advisory in effect for NW winds gusting up to
25kt with seas 3-4ft and a wave period of 5-6sec.

SHORT TERM: Small craft winds/seas expected late Wednesday
through early Thursday, with S winds switching to the W.
Otherwise, conditions mainly less than small craft through the
period.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory from 4 AM to 2 PM EDT Monday for ANZ050-
     051.

&&

$$


Near Term...Buster/Sinko
Short Term...Foisy
Long Term...Foisy
Aviation...Buster/Sinko/Foisy
Marine...Buster/Sinko/Foisy