Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 051313
Area Forecast Discussion
National Weather Service Caribou ME
813 AM EST Mon Dec 5 2016
High pressure that currently lies over New England this morning
will move east into Canada this afternoon. A weak trough of low
pressure will move across the area late this afternoon into this
evening. High pressure will return on Tuesday.
.NEAR TERM /THROUGH TONIGHT/...
800 AM Update...High clouds have quickly spread across the area so
updated forecast to go mostly cloudy north and cloudy Downeast.
Also lowered temps through mid morning with clouds preventing any
sunshine from warming the air.
Previous discussion...A ridge of high pressure will gradually
build east across the region this morning and exit into New
Brunswick this afternoon. A weak trough will follow in its wake,
moving off MA/NH coast late this afternoon and crossing the Gulf
of Maine overnight. The band of light snow associated with this
trough which is currently draped across central NY/eastern PA will
move into our western sections by mid to late morning and then
spread eastward across central/Downeast Maine through the
afternoon and evening. Snow accumulations will be minor, generally
around an inch from Greenville down through Bangor to southern
Hancock and Washington Counties. Locations north and east of the
Katahdin area will get a half inch or less; the Saint John Valley
will get a dusting at best. Today`s high temperatures will range
from the lower 20s in the Crown of Maine to around 30 in Bangor
and Downeast. The immediate coast will top out right around
freezing, so some rain may mix in with the snow this afternoon.
The trough will weaken as it pushes across eastern Maine overnight.
As such, expect snow will come to a gradual end from north to south
through the evening hours, lingering past midnight across far
Downeast. It`ll be another cold night over northern Maine with
temperatures dipping into the single digits. Lows are expected to be
in the teens to around 20 from the Central Highlands down to the
coast. Patchy freezing fog will be possible in the north,
particularly in river valleys and near any open water.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
High pressure both sfc and aloft will build across the region
Tuesday. The challenge in the north will be shallow inversions and
the possibility of low cloud and fog. If the low clouds form they
could hang tight all day Tuesday across northern areas. The
Down East region should have a m/sunny day. Highs Tuesday will
range from the mid 20s north to around or a bit above the freezing
mark in the Greater Bangor Region. The ridging moves east Tue
night as low pressure tracks just north of the Great Lakes and
another low develops off the Delmarva coast. A surface trough will
extend from the Great lakes Low and into western New England late
Tue night. High clouds will increase Tue night with most areas to
be cloudy or at least mostly so Wed. Tough to say how things will
evolve with low clouds/fog in far northern Maine Tue night, but
would expect a good deal of cloud cover. The best chance of fog
will occur if there are breaks in the clouds. A bit of overrunning
during the day Wednesday may lead to little bit of very light
snow or flurries, especially across the northern and western
zones, with a few sprinkles or flurries Down East in the
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The latest 00z GFS and Canadian have late week low development east
of the Maritimes with no big snow event for the CWA. The 12Z/4th
ECMWF still had a significant low that tracks right along the
Maine coast Thu night to near Eastport by 12Z Fri. About 2/3`s of
the 12Z ECMWF ensembles have no significant storm, with about 1/3
having advisory to warning level snowfall. The 00z/5th ECMWF now
has a much weaker low with most of the development taking place
east of the Maritimes. None of the 50 00z ECMWF ensemble members
have significant snowfall across the area with a fairly tight
clustering of low pressure developing east of Nova Scotia at 12Z
Fri. As the long range guidance is now in much better agreement will
go in that direction with the forecast with chance PoPs instead of
likely PoPs for Thu night. It is likely that later shifts will be
able to continue this trend of reducing the Pops. Cold air follows
for next weekend with some snow showers likely at times, especially
across the Crown of Maine. Temperatures next weekend are expected
to be 10 to 20 degrees below average, and the coldest air mass of
the early winter season.
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR conditions are expected to prevail at the northern
terminals through 12z Tue, with just occasional MVFR visibility
possible in freezing fog early this morning and again early
Tuesday morning. Ceilings will lower to 1500- 2500 ft this
afternoon at BGR and BHB as light snow moves in from the west.
Visibility will drop to 3sm at BGR after 23z Mon and remain so
until 03z Tue, while BHB will be reduced to 2sm during that time.
The snow will come to an end by 06z Tue and ceilings will rise to
above 3000 ft shortly thereafter.
SHORT TERM: Predominately MVFR with intermittent IFR at the northern
terminals Tue into Wed in stratus, although some breaks in the
clouds and VFR conditions are possible at times. Areas of fog may
also produce occasional VLIFR, especially Tue morning and late
Wed night. VFR expected at the Down East terminals Tue and Wed.
Variable conditons late in the week, but mostly MVFR to VFR.
NEAR TERM: No headlines will be needed today or tonight. High pressure
will cross the waters early this morning, followed by a trough of
low pressure this afternoon and evening. Winds will increase out of
the north once the trough moves east of the region late tonight.
Gusts to around 20 are expected. Seas will subside to 1 to 2 feet as
the trough crosses this afternoon, but will build back to 2 to 3
feet in response to increasing winds late tonight.
SHORT TERM: As cold air pours over the waters late in the week into
the first half of the weekend wind gusts to high end small craft
advisory or low end gales are possible.
Yesterday was the first day without measurable snowfall at
Caribou since November 28th.
The temperature dropped to -1F at Estcourt Station as of 2 am this
morning. This was the first sub-zero temperature of the winter
season across northern Maine.