Area Forecast Discussion
Issued by NWS Portland, ME-- Highlight Changed Discussion --
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FXUS61 KGYX 161337
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
937 AM EDT Thu Mar 16 2017
Low pressure will continue to pull away to the northeast today
through tonight. High pressure will build in from the west on
Friday and will crest over the region Friday night. Low pressure
will pass out to sea south of New England Saturday. High
pressure will gradually build in from the west Sunday through
Monday. A cold front will cross the region Monday night followed
by a secondary cold front Tuesday night.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --1337Z Update...
Minor changes to decrease PoPs slightly over the foothills and
keep them mostly confined to the mountains based on latest near
and short term guidance. QPF, temperatures, dew points, and wave
heights were also adjusted based on current observations.
Quick update to adjust temps/td/sky grids based on current obs.
Mostly clear skies downwind of the mountains will gradually
give way to clouds by late morning/early afternoon. Aside from a
few flurries in the north...remainder of the day should be dry.
No other changes planned attm.
Cyclonic flow will persist over the region today through
tonight as low pressure over the maritimes continues to slowly
drift of to the northeast. Will see a day much like Wednesday
downwind of the mountains with mostly clear skies this morning
giving way to clouds in the afternoon. In the north skies will
remain cloudy with occasional snow showers. Temperatures across
the region will range through the 20s to near 30 degrees.
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.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Clouds will persist in the mountains overnight along with a few
stray flurries. Skies will gradually clear downwind of the
mountains this evening. Low temps overnight will range from 5
to 10 north and will range through the teens south.
A narrow ridge of high pressure will build in from the west on
Friday. Lingering moisture from departing low pressure will
produce a mix of sun and clouds during the morning before
gradually clearing sets in during the afternoon. Highs on Friday
will range from the mid 20s north to the mid 30s south.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
The extended begins with high pressure nosing into the region
from Ontario Fri night. That should help see temps below
guidance...especially over the fresh snow pack. I dropped the
usual suspects 3 to 4 degrees below guidance.
Then for the second half of Sat we will watch a s/wv trof dig
thru the Great Lakes. Clouds should increase from the W in the
evening as the upper trof approaches. That H5 low has continued
to slip Swd with each successive model run...and 16.00z GFS is
trending in the direction of the Srn ECMWF. Both models are a
near miss for parts of the forecast area...as frontogenesis
aloft clips parts of Srn NH and coastal Wrn ME. 15.12z ECMWF EPS
continues to show a cluster of individual members NW and closer
to Cape Cod...and as such I am not willing to totally write this
system off yet. There is definitely some feature in the flow
that is causing about 1 in 4 or 5 members to amplify closer to
the coast of New England. I suspect that the s/wv trof moving
into the Pacific Northwest is playing a role...and that should
be fully sampled by regional raobs with the 12z soundings. If
any appreciable N trend fails to materialize with the 12z
runs...it will probably be time to trim the likely PoP out of
As that system pulls away early next week...brief surface
ridging crosses the area ahead of the next trof. This one looks
to usher in yet another blast of Arctic air midweek. While not
as cold as previous cold snaps...H8 temps around -20C...or
about 10 to 15 degrees below normal...are forecast. That should
add to an already well below normal monthly average temp.
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
Short Term...VFR today through tonight with areas of MVFR
ceilings in the mountains. VFR Friday.
Long Term...VFR conditions prevail Sat under the influence of
high pressure. Upper trof swings thru Sat evening...with SHSN in
the mtns. Farther S...some -SN may make it as far N at CON
during the overnight. A period of IFR conditions is possible
across Srn NH terminals...but confidence is low. Any lingering
-SN moves out Sun.
-- Changed Discussion --Short Term...Dropping gales for SCAs valid through this
Long Term...High pressure will nose over the waters to begin
Sat. As an upper trof swings across the Northeast...low pressure
will develop S of New England. It is forecast to deepen
quickly...but just a hair too far E to bring widespread
significant impacts to the waters. A period of near gale force
gusts is possible on the outer waters however. Winds and seas
diminish early next week...before a cold front crosses the
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MARINE...Small Craft Advisory until 6 PM EDT this evening for