Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
1208 am EST Tuesday Dec 10 2013
low pressure will move away to the east over while a weak wave of
low pressure will move south of the region Tuesday. A cold front
will cross the region Wednesday.
Near term /through today/...
midnight update: only very minor changes to forecast grids this update...
otherwise forecast msly unchgd from last update.
1037 PM update: let the winter weather advisories expire at 10 PM.
Some light snow expected to move across portions of the County Warning Area
through midnight. Additional accumulations of an inch or less. The
highest snowfall totals from the event so far have been across the
far northern tier of Aroostook County west/3-4 inches from Fort Kent
to Madawaska. Adjusted the temperatures a bit to show them to warm
overnight as seen by the 02z sf analysis west/some warming moving
into western Maine and across southwestern Maine. Quantitative precipitation forecast was adjusted to
bring the last 12 hour amounts down from previous thinking west/totals
no more than 0.25".
Orgnl disc: a fast moving and rather flat wave of low pressure
lifting out of the middle Atlantic region along a cold front will
slide south of the area on Tuesday. This may come close enough to
bring some patchy light rain or snow along the immediate coast or
just offshore. The system offshore will quickly move away to the
east late Tuesday with partial clearing downeast. Skies across the
north will remain partly to mostly cloudy on Tuesday.
Short term /tonight through Thursday/...
a strong cold front will approach northwest Maine later Tuesday
night. Expect mostly cloudy skies...with a chance of snow showers
late...across northern areas with partly cloudy skies downeast.
The cold front will cross the region Wednesday with a chance of
snow showers. Could have lingering snow showers early Wednesday
night. Cloud cover will then begin to decrease overnight Wednesday
while pressure builds toward the region. Partly cloudy skies and
much colder temperatures will occur across the region Thursday.
Temperatures will be at below normal levels Wednesday...with much
below normal level temperatures Thursday.
Long term /Thursday night through Tuesday/...
period will start out cold as surface high pressure will continue
to nose north Thursday night into Friday. Both the GFS and European model (ecmwf)
have a weak low developing across the Great Lakes and moving east.
Right now GFS is still most robust with quantitative precipitation forecast but thinking main
impact will be increased cloud cover Saturday into Saturday night.
Models do indicate a low pressure continuing to develop across the
Carolinas Saturday. The models have some divergence as to the
timing and track of this surface low. This is due to differences
in relation to the location and intensity of the closed upper
level low to our east and where the upper level jets couple. The
06z GFS keeps this surface low well to the south but the 00z GFS
ensemble mean brings the low out of the Great Lakes east. The 00z
European model (ecmwf) is a bit slower and brings low pressure into the Gulf of
Maine. It should be noted the European model (ecmwf) ensemble mean is in pretty
close agreement with the operational run. The 12z GFS came more in
line with the European model (ecmwf) although a bit faster. The latest 12z GFS is
highest with quantitative precipitation forecast especially downeast with the probability of precipitation being all snow.
This system is still late in the period with time to resolve
timing and location issues. Plan to stick with superblend at this
point with so much model uncertainty. Depending on track of the
low for Sunday it could be a breezy Monday across Maine with
tightening gradient and wrap around snow shower across the eastern
portions of Maine. Temperatures through the period will be below
Aviation /05z Tuesday through Saturday/...
near term: IFR conditions in low clouds and some precipitation this
evening will improve to MVFR after midnight then VFR on Tuesday.
Short term: occasional MVFR conditions are possible across northern
areas later Tuesday night. Otherwise...VFR conditions are expected
Tuesday night. Occasional MVFR conditions are possible across the
region Wednesday into early Wednesday night. Generally VFR
conditions are expected across the region later Wednesday night
through Friday. MVFR/IFR conditions could then develop Saturday.
near term: an Small Craft Advisory will be extended through Tuesday for wind gusts
over 25 knots. Some spotty light rain or snow may affect the waters
again on Tuesday.
Short term: Small Craft Advisory conditions are expected Tuesday
night through Thursday night. Visibilities could be reduced in
snow showers Wednesday.
Marine...Small Craft Advisory until 7 am EST Wednesday for anz050>052.