Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service Gray ME
748 PM EDT Thursday Apr 17 2014

Synopsis...
high pressure will shift east into the Maritimes this evening and
produce an onshore flow for our area through Friday. A cold front
will cross the region Friday night. High pressure will build into
the region Sunday and Monday. Another weak cold front will cross
the region Tuesday.

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Near term /until 6 am Friday morning/...
745 PM update: input latest mesonet data. Skies remain mostly clear and
temperatures on track with only a few minor tweaks for the next few hours.
No other changes at this time.

Previous disc;
at 18z...the 1045 millibar surface high was situated vicinity of
the Maine - New Brunswick border. Outside of a few high clouds on
GOES imagery...skies were clear across the forecast area. Even
with the strong sunshine...we were struggling to approach 40
degrees in many locations this afternoon...a good 15 to 20 degrees
below average for the date. We'll be mainly clear and cold again
tonight...but a degree or two warmer then last night...with no
low temperature records likely to be broken. The offshore low
cloud in the return flow around the surface high...could spread
into seacoast New Hampshire by dawn.

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Short term /6 am Friday morning through Friday night/...
on Friday...onshore flow around the surface high limits highs to
40s at the coast with some low cloud...patchy fog and drizzle
possible south of Portland. Otherwise...a partly sunny day with
warmest highs in the Connecticut valley with readings in the lower
50s.

A cold front crosses the region Friday night with some spotty
sleet...snow...and rain possible across the higher terrain with
its passage.

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Long term /Saturday through Thursday/...
no significant weather
events expected in the long term with models in fairly good agreement. Any
lingering mixed precipitation in the mountains early Saturday
should change to scattered showers before ending as temperatures warm.
High pressure should provide pleasant Spring weather for Sunday
into Monday. Warm advection on the back side of the high will
produce increasing high clouds Monday. Another weak frontal system
will bring the threat of showers to the region Tuesday. Models
currently show a low developing south of the region along the
front Tuesday night and Wednesday. The position of the front and
track of the low will determine whether showers persist into
Wednesday. Current model forecasts keep precipitation associated
with this low south and east of region. High pressure builds into
area for late in the week.

&&

Aviation /23z Thursday through Tuesday/...
short term /through Friday night/...VFR...with scattered MVFR possible
Friday morning in marine stratus vicinity of kpsm.

Long term...mainly VFR...with MVFR possible in mountains Saturday
morning in mixed precipitation and then across all the area in showers
Tuesday.

&&

Marine...
short term /through Friday night/...
we have some lingering 5 feet seas south of Portland this evening...then
seas outside the bays will reach 5 feet again Friday morning in onshore
flow with small craft seas likely to linger into Friday night. The
current Small Craft Advisory was converted to an Small Craft Advisory for hazardous seas with the
new marine package this afternoon.



Long term...Small Craft Advisory criteria possible Tuesday ahead of approaching
front...otherwise no flags.

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Gyx watches/warnings/advisories...
ME...none.
New Hampshire...none.
Marine...Small Craft Advisory for hazardous seas until 8 am EDT
Saturday for anz150-152-154.

&&

$$