Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 092319
Area Forecast Discussion
National Weather Service Caribou ME
619 PM EST Fri Dec 9 2016
An Arctic front will move through the region this evening. The
first Arctic air mass will settle over the area for the weekend.
Low pressure will approach Sunday night then cross the region
.NEAR TERM /THROUGH SATURDAY/...
618 PM update. winds across the area have not increase as
previously expected. Have updated to knock back the winds and
gusts particularly across the north. Made minor adjustments to
temps and skycon.
Previous discussion. The season`s first Arctic air mass will pour
into the area tonight with temperatures steadily dropping until
early Saturday. Steep low level lapse rates, a tight pressure
gradient and strong winds aloft will generate very windy
conditions tonight with gusts to 30-35 mph...especially this
evening. This instabilty and moisture under H850 will generate
snow showers though this evening. By later in the night, most
shower activity will be confined to the Saint John Valley. Wind
chills will drop below zero across the entire area tonight and
stay below zero into Saturday morning. Actual temperatures will
fall to the low single digits north tonight and low teens for
Bangor and the Down East region. The winds continue Saturday with
gusts to 25 mph producing the low wind chills. Highs will only
reach around 12F for the Crown of Maine and upper teens to lower
20s for Bangor and the Down East region.
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
High pressure will cross the region Saturday night through Sunday.
Expect partly cloudy skies north, with mostly clear skies across
the remainder of the forecast area Saturday night. Expect partly
sunny skies north, with mostly/partly sunny skies across the
remainder of the forecast area Sunday. High pressure moves east
Sunday night, while low pressure tracking across the Great Lakes
draws a warm front toward southern New England. Cloud cover will
increase across the region Sunday night. Overrunning snow will
then begin to develop across mostly Downeast and west-central
portions of the region later Sunday night with light accumulations
possible. The Great Lakes low will weaken while approaching
Monday, while a secondary low begins to develop to the east along
the warm front. Uncertainty still exists regarding whether the
secondary low develops near coast or across southern portions of
the Gulf of Maine. A track closer to the coast would bring more
significant precipitation to the region, though could also bring
warmer air toward the coast which could allow a snow/rain mix to
develop across the Bangor and Downeast regions. A more southerly
track would keep temperatures colder, though would produce less
precipitation particularly across northern areas. Additional snow
accumulations are expected Monday, though amounts are uncertain.
Temperatures will be at below normal levels Sunday/Monday.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Expect the winter storm to depart Mon night, with some snow
showers lingering up north after sunrise Tues. Mod to potentially
hvy snow Mon night will be mostly for the central and northern
CWA, though model differences in strength/position of the trailing
trof limit certainly on placement of heavier amounts. The CMC is
the most progressive on the Low/trof, and wld push most snow out
soon after 00z Tue. However, looking at other models gives
confidence on snow lingering after 00z Tue, with the GFS and NAM
having more snow than the ECMWF.
Moving on, models remain very scattered on solutions for a mid-
week system, both in terms of timing and precip amount potential.
As such, kept my POPs to Chance, capped at 50%, but spread that
between 12z Wed and 12z Thu. As of now, the temp fcst would yield
snow for all but the coastal zones for the duration of any event.
Operational GFS wld give more snow for the interior Downeast and
Bangor metro, with less snow up north. However, GEFS plumes reveal
a wider variation in the potential precip and temp solutions, with
some warmer solutions bringing less snow Downeast and more up
north. Tighter timing and higher certainty on precip type will
hopefully be possible in the near future. ECMWF and GFS both
pointing toward another arctic air intrusion late next week, with
temps well below normal.
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: Mostly MVFR cigs north of HUL until Saturday
afternoon. The exception could be IFR vis in snow showers at FVE
tonight. For BGR and BHB, a period of MVFR cigs is possible late
tonight, but otherwise, it will be VFR. Gusty winds will be a
factor...particularly tonight with NW gusts over 30 kts at times.
SHORT TERM: Generally expect VFR conditions Saturday night through
early Sunday night. Conditions will begin to lower to MVFR levels
later Sunday night, particularly across the Bangor and Downeast
region. MVFR to LIFR conditions are expected across the region
Monday into Monday night. Occasional MVFR conditions are possible
mostly across the north and mountains Tuesday. Conditions
Wednesday will be dependent on whether low pressure impacts the
region which remains uncertain at this time.
NEAR TERM: The small craft advisory will carry on through the
period with seas 5 to 8 feet and a few gusts even reaching gale
criteria of 35 kts. Since sustained winds over 35 kts are not
expected, will not convert to a gale warning.
SHORT TERM: Small craft advisory conditions are expected early
Saturday night. Could also have light freezing spray Saturday
night into early Sunday. Conditions are expected to be below small
craft advisory levels Sunday into Sunday night. Small craft
advisory level conditions are then expected Monday. Visibilities
will be reduced in snow and rain later Sunday night into Monday.
MARINE...Small Craft Advisory until midnight EST Saturday night for