FXUS61 KGYX 150754
Area Forecast Discussion
National Weather Service Gray ME
254 AM EST Fri Dec 15 2017
High pressure shifts east today. Weak low pressure to our north
and south will provide clouds, and maybe a few snow showers or
flurries Friday night into early Saturday. High pressure builds
in on Sunday and starts a warming trend. Although slightly
warmer, several fast moving systems could provide some light
precipitation early to mid next week.
The long wave trof over the northeastern CONUS has two separate
approaching short waves that will be watched, one approaching
from the Great Lakes while the other races well out to sea from
off the mid atlantic coast. In the meantime, high pressure moves
to the east later today. The day will start out sunny but very
cold. The afternoon will see increasing high clouds from the
southwest to northeast ahead of the approaching short wave over
the Great Lakes. Temps will start out very cold this morning and
will be slow to recover in the afternoon. Stayed with a blend
of guidance temps for highs.
An approaching short wave (clipper) from the Great Lakes will
spread clouds and scattered snow showers into the mountains
tonight into Saturday. Very limited moisture will be associated
with this system so little to no accumulations are expected.
Meanwhile the southern short wave that passes off the mid
atlantic coast and then well out to sea may spread some ocean
clouds into some coast areas for a time tonight but the northern
and western edge of the precipitation shield will stay off the
coast. Models in good agreement on this. Temps will be not as
cold tonight and Saturday and used a blend of guidance.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Northwesterly flow is established once Saturday's system shifts
offshore. Throughout the end of the weekend and the beginning
of the work week the upper level flow will become southwesterly
with fast moving impulses moving through and bringing periods
of precipitation to northern New England.
At the surface high pressure builds in through the day Sunday.
A warm front lifts ENE into the region late Sunday into Monday.
This feature eventually shifts south but showers will be
possible across south NH and ME as it does so. A more
significant storm system drives a cold front through the region
Tuesday. The parent low will be located well to the north in
Canada...but widespread showers are expected through Tuesday
night. Upslope showers will be possible in the mountains through
High pressure noses in briefly Wednesday night into Thursday.
Another clipper moves just north of the region Friday into
Saturday. Warm advection showers are expected Friday as the warm
front lifts over the area...before a cold front sweeps through
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Long Term...MVFR conditions possible Monday and Tuesday in snow
showers. Otherwise VFR.
Short Term...Winds have diminished this morning and will become
light by this afternoon and evening. After the passage of the
clipper on Saturday the northwest winds will increase and become
gusty and may require a SCA over the outer waters.
Long Term...Next chance of SCA winds will occur Tuesday
afternoon and evening with gales possible on Wednesday/
FXUS61 KCAR 150855
Area Forecast Discussion
National Weather Service Caribou ME
355 AM EST Fri Dec 15 2017
Low pressure in the western Great Lakes will move toward the
region tonight. Low pressure will intensify to the south of the
area tonight and is expected to pass well east of Nova Scotia
late tonight. High pressure will slowly build into the area from
the west over the weekend.
.NEAR TERM /THROUGH TONIGHT/...
A weak area of low pressure across the western Great Lakes early
this morning will move east into southern Quebec tonight. Low
pressure in western North Carolina will deepen rapidly today
along a strong baroclinic zone, and will be off the Delmarva
coast this evening, and will pass east of Nova Scotia tonight.
Today will start mainly sunny with some increase in mainly high
clouds this afternoon. It will remain cold with highs from 10 to
15 degrees in the Saint John Valley to the low 20s in the
Greater Bangor Region. Wind chills will be below zero across
much of the region this morning. Moisture will be scant with
the incoming low from the west, but perhaps just enough
for some flurries or an isolated snow shower after midnight
across the western Mountains. An inverted trough associated with
the ocean low will provide the focus for convergence, and with
an influx of ocean moisture some snow may brush the Downeast
coast. The models do not agree so much with some models and
ensembles keeping most of it offshore or to the south, but with
some brushing the coast with an inch or or two of fluffy snow.
Bumped up the PoPs just a bit and have around an inch of snow on
the immediate coast and outer islands, but with little or no
snow expected in the Greater Bangor Region.
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
Northwest flow aloft will keep temperatures below normal through
the upcoming weekend. There could be a bit of snow first thing
Saturday morning along the down east coast in association with
inverted trof/ departing oceanic low. Could also see a few
flurries or snow showers across northern and central portions of
the region associated with mid level short wave moving southeast
from the Great Lakes region. Otherwise expect partly sunny skies
by afternoon. Highs on Saturday will range from the mid and
upper teens north and low to mid 20s down east. Saturday night
looks to be mainly clear and continued cold as high pressure
starts to build east from central Canada. With the high still
well to our northwest there should still be a fairly decent
gradient across the area limiting radiational cooling
potential. That being said, we are still looking at lows ranging
from the single digits below zero north to 5 to 10 above across
central and down east. Sunday will feature abundant sunshine
with light winds as high pressure builds right across the
region. Highs on Sunday will only range from around 10 above
across the far north and low to mid 20s down east.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Looks like decent radiational cooling conditions are possible
Sunday evening as high pressure slides across the region and
into the Canadian maritimes. Clouds will be on the increase late
Sunday night in advance of the next short wave approaching the
region from the west. This system has the potential to bring a
chance of light snow to the region on Monday. 00z
NAM/EC/Canadian would support this solution with GFS the drier
model. For now, only low pops (30 to 40%) were indicated for
Monday, with the greater chances down east. Looking further
ahead, weak short waves are forecast to cross the region through
the extended period with snow showers north and snow or rain
showers down east. Temperatures do begin to moderate to closer
to normal by mid week as upper flow becomes more zonal across
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR expected today and tonight. A brief period of
MVFR possible in -sn at KBHB later tonight.
SHORT TERM: Mainly VFR Saturday through Sunday night. MVFR/IFR
possible in some light snow or snow showers Monday into Tuesday.
NEAR TERM: A small craft advisory remains in effect this
morning. The gradient slackens by around midday as high pres
builds over the waters into this evening. A few gusts may
approach 25 knots on the coastal waters late tonight as an ocean
storm passes well to the south and east of the waters.
SHORT TERM: Small craft advisory level conditions are possible
Saturday into Saturday night.
ME...Wind Chill Advisory until 9 AM EST this morning for MEZ001-003.
MARINE...Small Craft Advisory until noon EST today for ANZ050>052.