Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCAR 072207
Area Forecast Discussion
National Weather Service Caribou ME
507 PM EST Wed Dec 7 2016
-- Changed Discussion --Low pressure north of the Great Lakes region will move northeast
through tonight. A cold front will approach from the west Thursday
and cross the region Thursday night and Friday. A much colder air
mass will follow for the weekend.
-- End Changed Discussion --
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --510 AM Update...Adjusted the wx element this evening for some
patchy freezing drizzle. Latest NAM and RAP soundings showed the
potential for freezing drizzle this evening. Will issue a Special
Weather statement to address this through 8 pm. Temps were
adjusted as well as the pops to account for some light precip on
A low pressure southeast of the area will continue to track to
the east away from the area. A second low over James Bay will
remain stationary co- located with the upper level low. A high
pressure ridge will build north along the Atlantic seaboard
through Maine into eastern Canada. Friday morning the ridge will
build east and the low over James Bay will move east over central
Quebec with a cold front extending back across the Great Lakes.
Scattered snow showers will develop ahead of the cold front. By
the end of the period, the low over Quebec will shift east, the
associated trough moves into western Maine.
-- End Changed Discussion --
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
For Thursday night, an upper level trough will cross the area with
colder air aloft. Surface temperatures will remain relatively
mild with lows in the upper teens to lower 20s. The resulting
instability will likely produce some snow showers...mostly towards
northern Aroostook and Piscataquis counties. The snow showers will
continue into Friday morning. The first Arctic air mass of the
season will arrive Friday afternoon with increasing winds, falling
temperatures and the threat of snow squalls in northern zones.
Highs on Friday will generally be in the morning. Strong cold air
advection will continue Friday night. This will create steep low
level lapse rates and very windy conditions through the night with
gusts over 30 mph...especially in northern zones. Snow showers
will likely continue in the north through the night and into
Saturday. Although guidance reduces pops after Friday evening,
have kept flurries in the forecast through Saturday. Wind chills
will drop below zero in northern zones later Friday night and stay
below zero on Saturday. Highs on Saturday will range from the
mid-teens north to mid 20s along the coast with gusty northwest
winds continuing. On Saturday night, there is potential for
subzero temperatures north if the wind dies off, but will go with
low single digits for now and low teens for Bangor and the Down
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
On Sunday, high pressure will cross the area in the morning and
high overrunning clouds will increase through the afternoon.
Guidance is indicating that a low will move out of the Great
Lakes region with warm frontal precipitation in the form of snow
on Sunday night. Have used a composite of the guidance to generate
a secondary low along the Down East coast on Monday. This means a
changeover to rain along the coast. There`s still a lot of
question on the exact path of the storm and other important details
such as the strength of the warm air advection. The warm advection
depends on whether the storm rides quickly east or a negatively-
tilted trough develops as suggested by the 07/12Z ECMWF. The
thermal profile suggested by a blend of guidance keeps Monday`s
highs below freezing north of a line from Bangor to Calais. Areas
north of this line stand a reasonable shot at plowable snow from
this storm as the secondary low deepens. After this storm exits
late Monday night, there will be a brief respite on Tuesday before
a bitterly cold round of Arctic air arrives Tuesday night. This
air mass is reminiscent of a few events during the very cold
2008/2009 winter season.
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: Mainly IFR early in the period with scattered snow showers.
SKYCON will scatter out this evening becoming VFR. Fog will form
near any bodies of water early tomorrow morning bringing VSBY and
SKYCON BACK to IFR through mid morning. MVFR through mid day, then
IFR as the trough moves into western Maine bringing a fresh round
of snow showers to the area.
SHORT TERM: Expect mostly MVFR cigs with tempo IFR vis in snow
showers north of HUL. This will occur Thursday night into
Saturday. BGR and BHB will be mostly VFR during this time. All
sites will likely be VFR Saturday night into Sunday. IFR to LIFR
in snow will develop Sunday night into Monday.
NEAR TERM: Winds and seas will begin to build tomorrow afternoon reaching SCA
criteria around the end of the period.
SHORT TERM: Expect small craft advisory criteria to be met
Thursday night and continue into Saturday evening. However, wind
gusts will likely exceed gale criteria later Friday afternoon into
Saturday morning and have opted for the gale watch to cover this
MARINE...Gale Watch from Friday afternoon through Saturday morning for