Area Forecast Discussion
Issued by NWS Caribou, ME-- Remove Highlighting --
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FXUS61 KCAR 110341
Area Forecast Discussion
National Weather Service Caribou ME
1041 PM EST Sat Dec 10 2016
Cold high pressure will build across the region tonight then move
out into the Atlantic Sunday. Low pressure from the Great Lakes
region will approach Sunday night, redevelop along the Maine coast
on Monday, then move east across the maritimes on Tuesday.
.NEAR TERM /THROUGH SUNDAY/...
1040 pm update...
With clds still impacting CWA tonight and winds likely to keep
from decoupling hv bumped mins up by a few degrees areawide.
Lowest dwpts are at -1F in the St. John Vly with most ob sites
in the immediate vicinity well abv 0F. Single digits still progged
for nrn areas with low teens along the immediate coast. Outlying
vly areas may drop blo zero but these locales wl be the exception
rather than the rule. No other chgs needed at this time.
Prev discussion blo... Overnight, temperatures should drop to
subzero readings north of a Topsfield to Millinocket line. Expect
single digits elsewhere except on the coast where low teens are
forecast. The challenge in the forecast will be winds as the high
will stay west and the resulting pressure gradient could keep
winds from becoming calm. Cirrus cloud cover will also be present.
These could prevent the boundary layer from decoupling. Did drop
temperatures from the previous package by several degrees and
below all consensus guidance packages. With this Arctic air mass
and the relatively mild temperatures so far this season, the bias-
corrected guidance seemed the worst. There is some risk that the
normally colder, sheltered northern sites could drop towards -10F,
but probably not lower. For Sunday, the guidance continues to be
solid in bringing highs up to the mid- upper teens north and lower
20s for Bangor and Down East region. Around round of stratocu is
possible for Sunday afternoon in Aroostook County, but overall,
little cloud cover is expected since the high overrunning clouds
with Monday`s storm should hold off until evening.
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
High pressure will exit east across the maritimes early Sunday
night, while low pressure crossing the Great Lakes draws a warm
front north toward the region. Clouds will increase early Sunday
night, with overrunning snow expanding northeast across the
forecast area later Sunday night. Overnight snow accumulations of
1 to 3 inches are possible across southwest portions of the
forecast area overnight Sunday, tapering to less than an inch
across northeast areas. The Great Lakes low will weaken while
moving east Sunday, with a secondary low developing across the
region and moving toward the maritimes. However, uncertainty
still exists regarding whether the secondary low develops along
the coast or southward across the Gulf of Maine. A track closer to
the coast would bring warmer air onshore which could allow the
snow to mix with or change to rain along the Downeast coast. A
more offshore track would keep colder temperatures along the coast
with precipitation remaining mostly snow. Generally expect
precipitation to remain in the form of snow across the remainder
of the forecast area Monday with additional snow accumulations
expected though exact amounts are still uncertain. The deeper
moisture will begin to move northeast later Monday afternoon
allowing precipitation to begin diminishing across southwest
portions of the forecast area. However, patchy freezing drizzle
could occur across these areas with the loss of deeper moisture.
The low will exit across the maritimes Monday night. Could still
have lingering wrap around snow across mostly northern and eastern
portions of the forecast area early Monday night where additional
light snow accumulations are possible before the snow tapers to
snow showers. Generally expect 5 to 7 inches of total snow
accumulation across much of the region through early Monday
night, with locally greater accumulations possible. Lesser snow
accumulations are expected along the Downeast coast where a
rain/snow mix could limit accumulations near the immediate coast.
High pressure will cross the region Tuesday with mostly cloudy
skies along with a slight chance of snow showers across the north
and mountains, with partly sunny skies across the Bangor and
Downeast regions. Temperatures are expected to be at below normal
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Expect rounds of scattered snow showers through much of next week
as an upper trough slowly crosses southern Canada. A potent cold
front will precede this trough across Maine late Wednesday into
Wednesday night. Bitterly cold air will follow this front;
Wednesday`s highs will be near normal, but Thursday and Friday
will be quite chilly with highs only around 10 above in the north
and 15 to 20 in the south. Low temperatures meanwhile will be in
the single digits below zero over northern and central portions of
the region, with some of the usual cold spots in the North Woods
dropping into the teens below zero. Bangor and Downeast should
remain in the positive single digits. High pressure looks to build
in for Friday, bringing snow showers to an end. Friday will be the
coldest day of the week though; temperatures only expected to peak
5 to 10 above in the north and 10 to 15 above for the Central
Highlands and Downeast, though the immediate coast will be closer
to 20. A storm system will approach from the southwest on
Saturday, with snow spreading into out southwestern areas during
the afternoon hours. Saturday will be some 5 to 10 degrees warmer
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR next 24 hours with mid-high clds skirting across
terminals tonight. Low VFR cigs over northern terminals expected
after 17z Sunday.
SHORT TERM: VFR conditions early Sunday night will lower to
MVFR/IFR levels overnight. Generally expect IFR/LIFR conditions
Monday through early Monday night, with MVFR/IFR conditions later
Monday night. Occasional MVFR conditions are possible across the
north and mountains Tuesday, with VFR conditions Bangor and
Downeast. Occasional MVFR conditions are possible across the
region Wednesday. Occasional MVFR conditions are possible across
the north and mountains Thursday with generally VFR conditions
Bangor and Downeast.
NEAR TERM: Winds expected to stay abv 25kts for next several
hours. Hv extended SCA for outer waters through 08z tonight and hv
cancelled intracoastal zone for tonight. Seas will remain just
below 5ft during the night.
SHORT TERM: Small craft advisory conditions are expected later
Sunday night into Tuesday. Visibilities will be reduced in
snow/rain later Sunday night through early Monday night.
High tide Monday morning is at 8:35 AM in Bar Harbor and 8:44 at
Eastport. Tides will be approaching astronomical high tides with
Monday being the day before the full moon. Onshore flow ahead of
approaching low pressure combined with the perigee tides may result
in high tide levels above normal and possibly some minor splash-over
MARINE...Small Craft Advisory until 3 AM EST Sunday for ANZ050-051.