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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 251608
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1208 PM EDT Sun Oct 25 2020

.SYNOPSIS...
High pressure will build across the region today, then exit
across the Maritimes tonight. Low pressure will approach later
Monday, then cross the region Monday night. High pressure will
cross the region Tuesday through Wednesday. A cold front will
cross the region Thursday. High pressure approaches the region
Friday and Saturday.
&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
High pressure will build toward the forecast area this afternoon
with partly/mostly sunny skies. North/northwest winds will gust
up to 20 to 25 mph. High temperatures will range from the upper
30s to lower 40s north, to the mid to upper 40s Downeast. Have
updated the forecast to adjust for current conditions along with
afternoon temperatures and clouds. The Small Craft Advisory for
the intracoastal waters has been allowed to expire with this
update.

Previous Discussion...
High wl be over the state by 00z tonight with winds going near
calm. This wl allow temps to rapidly drop with sunset under clr
skies. Mid-high clds wl begin to spill in fm the west and likely
keep temps from dropping after 06z acrs the west. Because of
the timing of clds min temps wl drop into in the upr-teens in
the deeper vlys over the north. However, if clds are not as
quick to move in cannot rule out the possibility of lower temps.
&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
High pressure will be sliding east of New Brunswick Monday
morning. In the low levels, east winds will push dry air into
Downeast while a surge of moisture aloft arrives from the SW. It
will take some time for the column to fully saturate and for
precip to reach the surface, so have trended back arrival time
by a couple hours Mon morning.

Once precip overspreads the area Monday afternoon, temperature
profiles will support all rain across Downeast and the coast up
into the Penobscot and Bangor Region. It isnt as simple
further north.

A mix of frozen precip will greet the Central Highlands and
North Woods Mon afternoon. The forecast mix of
rain/snow/sleet/fzra will largely depend on local elevation, as
well as how much cold air remains in the NW shadow of the
Longfellow Mtns. The highest summits will be in for a glaze of
ice early as temperatures begin well below freezing and profiles
above 6000 suggest enough warm air to melt precip. Warm air
below 800mb makes a push into the region later in the afternoon,
allowing a changeover to all rain until the trough swings
through after midnight and temps again fall below freezing. Some
remaining snow showers will be possible, but precip will be
tapering off into early Tues morning.

Up in the St. John Valley and far North Woods, a mix of rain
and snow will be the predominant precip type, with enough
consistent snow possible for light accumulations of around an
inch along the NB border.

Temperatures will support mainly rain in eastern Aroostook.
Without much terrain to dam up cool air from southeasterly flow,
warm temperatures should flush in Monday morning. It will be a
cold rain, with temps struggling to make it past 40. Remaining
rain showers will mix with snow showers late Mon night as
temperatures fall behind the front.

GEM and ECMWF guidance suggest low pressure strengthening in
the Gulf of Maine, which would position parts of Interior
Downeast in a bit of a embedded deformation zone and thus some
enhanced convergence/lift. This may lead to increased rainfall
rates, however have kept QPF on the lighter side given the PWATs
only approaching 1 inch (still above 75% average).
Some elevated instability arrives along the coast where a
nocturnal rumble of thunder is possible over the coastal waters.

Precip will taper quickly Tuesday morning as cool, dry air is
introduced behind the front from the NW. Clouds will linger with
moisture still in the low levels. High temperatures will be
similar to Monday, topping out in the mid 40s Downeast, and
upper 30s in the North Woods.
&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Temperatures will remain on the cool side in the long term as
Maine remains in a cooler air mass. Dominant high pressure moves
overhead Wednesday with dry conditions expected amid the
provided subsidence.

How this high exits (and trough enters from the west) will help
play a role where a potential large storm system tracks into the
East Coast late week. Guidance has shown this system for a
number of runs now, but kept the bulk of precip suppressed well
to our south, only making it as far north as southern New
England. Decided to keep slight chance PoPs in much of Downeast
for this time period as some trends bring the northern fringe of
QPF into southern and eastern Maine. The potential exists for a
lot of moisture to be with this system, as it could contain
remnants of Zeta in addition to strong southerly moisture
advection. Remains plenty of time to assess this system and
refine the forecast over the coming days.
&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: Generally expect VFR conditions across the region
this afternoon through tonight. However, local MVFR ceilings are
possible through early afternoon. North/northwest winds will
gust up to around 20 knots.

SHORT TERM:
Monday...VFR early then lowering to MVFR/IFR with developing
rain. A rain/snow/sleet mix possible across northwest areas.

Monday night...IFR/LIFR early, improving to VFR/MVFR late. A mix of
rain/sleet/snow early, transitioning to snow showers overnight
north. Rain early, transitioning to rain showers overnight
Downeast. Wind shifting SE to NW.

Tuesday...Generally VFR. MVFR possible early Downeast.

Tuesday night...MVFR possible Downeast , otherwise, VFR.

Wednesday through Wednesday night...Generally VFR. MVFR possible
late Wednesday night north with a chance of rain/snow showers.

Thursday...VFR/MVFR. A chance of rain showers Downeast.
&&

.MARINE...
NEAR TERM: The Small Craft Advisory for the intracoastal waters
has been allowed to expire with this update. A Small Craft
Advisory remains in effect for the remainder of the waters
through 4 PM. Conditions will be below small craft advisory
levels on all the waters tonight.

SHORT TERM: Conditions below SCA with waves generally 3 to 4 ft
Monday and Tuesday, becoming 2 to 3 ft through Wednesday night.
Patchy fog may form Monday afternoon, with a rumble of thunder
possible in the evening and overnight. Winds shift SE to NW
Monday night, gusting to around 20 kt.
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ050-
     051.

&&

$$

Near Term...Norcross/Farrar
Short Term...Cornwell
Long Term...Cornwell
Aviation...Norcross/Cornwell
Marine...Norcross/Cornwell