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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 090540
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1240 AM EST Mon Dec 9 2019

.SYNOPSIS...
A warm front will cross the area tonight through early Monday.
Low pressure will track northwest of the region Tuesday. A cold
front will cross the region Tuesday night through early
Wednesday with strong high pressure building into the area on
Thursday.

&&

.NEAR TERM /THROUGH TODAY/...
1230am Update...
No changes needed to the forecast. Cloudy night with warmer air
moving in and a bit of light mixed precipitation.

Previous Discussion... Mid-cloud deck has overspread wrn half
of the area this afternoon in area of warm advection. Temps hv
increased thru the 20s with coastal areas in the lwr 30s. Light
precipitation being seen mvg thru srn Quebec and approaching the
state with lgt snow and/or flurries likely ovr the St. John Vly
this afternoon and evening. Expect that temps wl cont to rise
drg the course of the overnight with temps at 00z lkly being the
low temps for tonight.

Warm advection lgt snow expected to traverse acrs the north this
evng bfr dvlpng ovr the rmndr of the region thru daybreak as
warm advection lift increases. Given the warming airmass expect
that pcpn wl be all rain south of a Bangor to Topsfield line at
onset and mainly snow to the north with a rain/snow mix line in
between for a period of time this morning. Cannot rule out a
glaze of ice due to vry lgt frzg rain or frzg drizzle early in
the morning mainly in a corridor fm about Millinocket to
Houlton.

Moisture wl exit the dendrite region acrs the north btwn 12z and
18z with a period of drizzle or freezing drizzle. Moisture
returns aft 18z to return nrn areas to mainly rain aft this time
as high temps wl warm into the u30s ovr the south and u40s for
Downeast.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
Monday evening, rain will be ongoing across the area as SW
oriented mid-level jet noses into Northern New England. This
exit region supports divergence aloft, with area of lower level
convergence over Downeast. As strong southerly LLJ drives into
the ascent, some guidance QPF values are showing potential for
convective precip. This paints some localized areas of enhanced
rainfall among the potent IVT current and PWATs between
1-1.5. Feel very confident in continuing moderate rainfall
through Monday night Downeast, and for a shorter period into
cntrl/ntn ME, but would like to see greater deep moisture
values to increase QPF or rates.

Wind will also be a notable concern. As downstream spreading of
isobars occurs over northern Quebec and the Maritimes, the
parent low pressure system will continue to strengthen with
intensifying low-level jet along the eastern US coastline. Focus
of winds will be running into the Downeast coastline Monday
night. Surface gusts would be greatest along the immediate
coast, close to 60 mph. Inland, winds appear to drop off, but
the LLJ will still be roaring overhead around 80kts. If
convective elements do form with heavy rain, some higher gusts
could mix in further inland Downeast. NAM guidance currently
indicates pockets of elevated instability, 80-160 j/kg, during
this time frame.

Precip will be tapering to showers Tuesday morning as dry air
moves in behind. Most of the remaining moisture focuses along
the coast as cold front sweeps through shifting winds from the
west. Due to slow moving upper trough and strong SW/NE oriented
jet, a boundary with moisture will reside off the east coast.
This feature exhibits little eastward progression through
Wednesday, providing the chance for rain showers to transition
to light snow after cooler air passes through the state.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
High pressure pushed into the Ohio Valley and east towards the
coast Thursday. This will provide a couple days of dry weather
from Crown to coast. Temperatures in the air mass will be cold
however, with highs on Thursday in the lower teens across the
north and lower 20s Downeast. Overnight lows, similarly cold, in
the single digits below in the north to lower teens Downeast.

The next system approaches during the weekend, although there
continues to be disagreement for timing, progression, and
evolution. This will play a role in precip type and amounts.
With residual cold air in place, easterly winds will hamper warm
surface temps. Will need to watch for mixed precip, namely
freezing rain, once guidance converges on a consistent track.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR conditions expected to diminish to MVFR late
tonight. Downeast terminals likely to rmn VFR through about 15z
before dropping to MVFR after this time. LLWS at 2kft expected
mainly at southern terminals.

SHORT TERM: Monday night...IFR to LIFR expected with rain.
Strong south to southwest winds expected (especially BGR and
BHB) with significant low level wind shear likely. Fog is also
possible.

Tuesday to Tuesday night...IFR to start the period with south
to southwest winds shifting west-northwest with a frontal
passage overnight. Precipitation may transition to snow and
prolong IFR/LIFR conditions with the greatest chance along the
coast during the evening and overnight hours.

Wednesday to Wednesday night...Mainly VFR with localized MVFR
in light snow showers. Light to modestly breezy west winds are
expected.

Thursday to Thursday night...VFR conditions are expected with
gusty west-northwest winds.

&&

.MARINE...
NEAR TERM: Winds wl increase to gale force this evening and
diminish after 12z Mon morning. Winds wl remain above SCA levels
through the day before ramping up toward gales toward the end of
the period. Seas will increase toward 10ft late tonight and
remain elevated thru the day tomorrow.

SHORT TERM: Gusts to storm force are expected Monday night and
a storm watch is in effect through 12z Tuesday. Patchy fog.
Seas upwards of 15 feet in the outer waters, 7 to 10 feet closer
to outer coastline. Winds will decrease rapidly and seas soon
thereafter Tuesday into Tuesday night, with small craft advisory
criteria likely being met through at least Wednesday night.
Winds and seas drop below SCA by Thursday afternoon as high
pressure builds overhead.

Surge from income storm Monday will be out of phase with already
low astronomical tides, thus coastal spashover will be
minor/limited during high tides.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Wind Advisory from midnight tonight to 5 AM EST Tuesday for
     MEZ011-015>017-032.
     High Wind Warning from 7 PM this evening to 5 AM EST Tuesday
     for MEZ029-030.
MARINE...Storm Watch from this evening through Tuesday morning for
     ANZ050>052.
     Gale Warning until 10 AM EST this morning for ANZ050>052.

&&

$$

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