Area Forecast Discussion
Issued by NWS Portland, ME

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300
FXUS61 KGYX 160352
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1152 PM EDT Sun Sep 15 2024

.SYNOPSIS...
High pressure will continue fair weather and above normal day
time temperatures through mid week. Low pressure moving up the
East Coast will bring low chances for rain late Wednesday and
Thursday. A cold front drops south out of Canada late in the
week bringing temperatures closer to normal with high pressure
building in next weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

11:50PM Update... The forecast remains on track under clear
skies. Tweaked temps to trends so far this evening, but
otherwise no changes to the forecast at this time. Some patchy
fog is starting to appear, and will continue to slowly expand
through the valleys overnight.

7:05pm Update... No notable changes with this update as the
forecast remains on track. Clear skies prevail, with temps
steadily cooling off through the evening. Lows dip into the 40s
and 50s again tonight, but don`t look to be quite as cool as
last night.

Previous...

A mid level ridge is anchored over the Northeast this afternoon with
a surface high pressure system centered over the Gulf of Maine.
These features will not move much tonight through Monday night.
Mostly clear skies and light winds will allow for efficient
radiational cooling tonight, which will bring lows down to the low
50s to upper 40s. Patchy fog is possible across much of the area
with valley fog likely. Valley fog could be locally dense along the
CT River Valley.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
Monday will be a few degrees warmer than today as temperatures aloft
increase. Fog will dissipate within a hour or two of sunrise, while
along the CT Valley fog may persist until 9 AM. Skies will be mostly
sunny for the rest of the day with highs will into the 80s across
the interior while an afternoon sea breeze keeps the immediate coast
in the 70s.

Low pressure moving through the Carolinas towards the Mid Atlantic
will spread some high clouds into the region late Monday night.
Still, conditions look favorable for some radiational cooling with
lows dropping into the 50s and the formation of valley fog.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Overview: Rex blocking slowly breaks down to end the week. Temps
will trend cooler...and while widespread precip remains unlikely
there will be some chances for showers towards the middle of the
work week.

Impacts: No weather impacts anticipated in the extended...but there
is a chance for some measurable rain towards the middle of the week
which will be a welcomed sight.

Forecast Details: As usual the breakdown of the block will be slow
going. The remnants of a subtropical disturbance off the Southeast
coast will drift inland and north along the East Coast. That will
provide our only real chance at organized precip over the next week
or so. How far north the deeper moisture and showers will make it
depends on a S/WV trof forecast to drop thru the St. Lawrence
River Valley. The timing may force the disturbance south of the
forecast area and ultimately leave much of the area high and dry
yet again. Right now ensemble probabilities of measurable
rainfall are quite low...no better than climatology. I have
trimmed the NBM PoP and also narrowed the window a
bit...especially on the front end. Otherwise the increasing deep
moisture will support diurnal isolated to widely scattered
showers to end the week and into the weekend.

Temps will generally slowly fall thru the week. It will start
well above normal...with temps in the 80s. Increasing cloud
cover will limit diurnal ranges more towards the middle and end
of the week...but readings should remain in the 70s. By the
latter half of the week high pressure building back in from the
north should allow for some seasonably cooler overnight readings
along with a return of valley fog.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
Short Term...Valley fog will likely bring LIFR to KLEB and KHIE
tonight with restrictions possible at KCON as fog is forecast to
develop there as well. Remaining TAF sites likely remain VFR
overnight. Fog dissipates between 12 and 14Z Monday morning with
prevailing VFR through the day. Another night of restrictions in fog
is likely at KLEB and KHIE Monday night.

Long Term...Largely VFR conditions expected to prevail during
the day thru Fri. Early in the period local LIFR expected in
valley fog...especially at LEB and HIE. By the middle of the
week onshore flow may allow for some marine stratus and IFR is
possible at all terminals.

&&

.MARINE...
Short Term...High pressure over the Gulf of Maine will continue quiet
conditions over the waters tonight through Monday night.

Long Term...Winds and seas expected to remain below SCA
thresholds until the very end of the week. A disturbance
continues north...the northeast flow along the coast will be
breezy and persistent. This will lead to some gusts near 25
kt...and seas building to near 5 ft outside of the bays by Fri
or Sat.

&&

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

&&

$$


NEAR TERM...Clair
SHORT TERM...Schroeter
LONG TERM...Legro