258
FXUS61 KGYX 191526
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1126 AM EDT Fri Jul 19 2024

.SYNOPSIS...
A dry and seasonable pattern is expected through the upcoming
weekend and into early next week. High pressure will slide south
of the region through Saturday. Outside of a few mountain
showers Saturday night...the next chance for precipitation
across the area does not arrive until next Tuesday in the form
of showers and thunderstorms ahead of a cold front.

&&

.NEAR TERM /TODAY/...

1125am Update...Minor edits to temps/dewpoints to get them in
line with the latest observed values.

935AM update...Little in the way of changes needed to the
forecast. High temperatures were raised by a degree or so in a
few locations where hourly temperatures were warming a little
ahead of schedule.

630am update...Looks like the dry air is doing well and staved
off much valley fog development overnight. Don`t expect much
expansion this morning as sun quickly warms us up. Minimal
changes to the going forecast otherwise.

Previous Discussion...
Seasonable and pleasant today as dewpoints have fallen 10+
degrees in the past 24 hours for much of the area. The
responsible cold front pushed offshore overnight, allowing this
drier air to take hold after a week of humid conditions.

Mostly sunny skies are expected today, but some cu development
is possible through the mid to late afternoon as PBL depth
increases. Model soundings are very dry aloft, and this should
keep these clouds fairly flat. Only standout item today would be
a sea breeze developing early this afternoon and pushing inland.
This will offer a wind shift as well as curb afternoon temps a
degree or two as it pushes inland.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Another refreshing night in store tonight as daytime mixing
ceases and skies remain mostly clear. Radiational cooling should
be favored, and have went lower in temps across the valleys in
the Whites as well as some common locations through the ME Lakes
Region and Midcoast. Temps overall fall into the 50s, but would
expect to see some locations dip into the upper 40s across the
north.

NW temp advection is lighter Saturday, and the area will be
poised north of high pres passing to the south. This should
allow area temps to rebound compared to Friday, pushing into the
mid to upper 80s away from the immediate coast. Dry air remains
in the region, but there may be an increase in high level cirrus
as moisture arrives aloft.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
High Impact Weather Potential: Minimal through early Tuesday.
Chances for showers and thunderstorms increase for Tuesday-
Thursday though confidence is low on any severe weather/hydro
threats at this range.

--Pattern and Summary--

The longwave pattern is expected to remain rather stable through the
long term forecast period with a substantial longwave ridge located
along the spine of the Rocky Mountains with troughs on either side
of this over the eastern Pacific and eastern North America. This
will keep the flow aloft generally from the west northwest or west
with H5 heights and T8s pretty close to...or just above seasonal
norms.  Through early next week...the modified Canadian airmass will
keep the weather quiet and dry.  By the middle of next week...the
eastern trough will reload as energy drops into the Great Lakes
region...allowing our flow to back southwesterly and allow a frontal
system to move through the region to end the forecast period with
what will likely be the most active portion of the forecast weather-
wise.

--Daily Details--

Saturday night through Monday: A cold front crosses the area
Saturday night with a few mountain showers....but frontal timing
and thinning moisture plume suggests little overall rainfall.
Drier and somewhat cooler air sinks in from the north for
Sunday...with decreasing clouds and mountain high temperatures
in the 70s. Further south...T8s won/t change too much from on
Saturday...and therefore 80s are again expected for highs. The
drier airmass will allow for more substantial cooling Sunday
night with some mountain valley locations likely reaching the
upper 40s while 50s to just above 60 is likely further south.
High pressure remains in control through Monday with some weak
moisture return as the flow aloft begins to back ahead of the
next shortwave/cold front dropping into the Great Lakes region.
Generally neutral temperature advection should allow for similar
daytime highs...mid/upper 70s in the mountains and 80s to the
south.

Tuesday through Thursday: The second half of the long term forecast
turns more active as the eastern trough initially reloads over the
Great Lakes...with a positive tilt allowing the flow over the
northeast to turn more southwesterly...allowing for building
moisture.  A weak front dropping into the region Tuesday may spark
some showers and thunderstorms with this trend continuing through
Wednesday as the flow remains generally parallel to the front
causing it to stall and service as a llevel focus for lift.  Global
ensembles differ on the eventual evolution of the upstream
positively tilted trough across the Mississippi Valley and
additional shortwave energy diving out of Canada.  With the
likelihood that the overall trough axis remains west of our
longitude through Thursday will necessitate a continuation of
shower/storm chances with building humidity but temperatures close
to seasonal norms with clouds and precipitation potential.

&&

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
Short Term...Terminals remain VFR through Saturday. Terminals
along the coast will see an afternoon seabreeze cause a wind
shift before slackening overnight tonight. Some valley fog will
be possible after midnight tonight.

Long Term...VFR conditions should persist through Tuesday
morning with some morning fog possible each morning at HIE/LEB.
Tuesday afternoon will bring a chance of restrictions given a
chance for showers and thunderstorms.

&&

.MARINE...
Short Term...Breezy today and again Saturday, but values will
remain below SCA levels. Waves trend to 2 to 3 ft over much of
the coastal waters as high pressure approaches the Mid Atlantic
during the first half of the weekend.

Long Term...Winds/waves are expected to remain below SCA levels
through the long term forecast period Saturday night-Tuesday.
Thunderstorms are possible over the waters by Tuesday afternoon.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$


NEAR TERM...Combs/Cornwell
SHORT TERM...Cornwell
LONG TERM...Arnott