642
FXUS61 KGYX 161707 AAC
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
107 PM EDT Mon Sep 16 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 PM THIS EVENING/...
1237 PM Update: Temperatures have rebounded nicely with only a
few Cu keeping the vis imagery from being completely clear early
this afternoon. Just a few minor adjustments for
temperatures/dewpoints through the afternoon.

925 AM Update: Fog has been a bit slow to burn off in the
valleys this morning...holding back temperatures a bit. Have
adjusted the near term temperature trend...but expect values to
quickly push towards inherited values once the fog burns off.
Warm...dry day expected with 12Z GYX RAOB showing a deep
warm/dry airmass aloft. No other significant changes at this
time.

645 AM...Valley fog showing up nicely across the NE CONUS this
morning on the nighttime microphysics graphic /still waiting on
the visible/. Otherwise no changes to the forecast other than
usual adjustment for current obs.

Previously...Elongated W-E sfc ridge stretch across N New
England today, as strong 590 dam ridge extends from the Great
Lakes east to S of Newfoundland, with ridging at all heights in
between. This combine with warm mid level temps near 15C, should
make for a sunny and very warm day, considering its mid
September. Of course, were starting off with vly fog yet again,
which should burn quickly outside of the sheltered mtn valleys
and the CT vly, which may take until closer to 0900 or so once
again. Onshore flow develops again today, but it will develop
later, and make less headway inland from the coast. So, were
looking at maxes of 80-85 across most areas away from the coast
and more like 75-80 on the coast.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
The ridging from the sfc thru 500 mb remains in place tonight,
and it won;t be much different from Sunday night, with valley
fog likely and patchy fog in other sheltered areas. Min temps
will be slightly warmer, but only by a few degrees, ranging from
around 50 to the mid 50s.

By Tuesday will start to see the riding across all levels start
to gradually weaken, as it is impinged upon by 500 mb trough
well to the NW, and 500 MB closed low associated with pseudo-
tropical system moving NW toward the OH valley. Overall,
forecast wont be much different from Monday with mainly sunny
skies /some patchy thin cirrus will likely move in/and highs
again in the 80-85 range.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
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 /18Z MONDAY THROUGH FRIDAY/...

Short Term...

Summary: High pressure will remain centered just east of the
region through Tuesday night with quiet weather conditions
otusde of morning valley fog.

Restrictions: VFR through the period outside of morning fog at
HIE/LEB/RKD and CON.  Confidence is least at CON...but will include
it for a short time...with a very similar setup to last night.
Otherwise...some high clouds /25kft/ expected on Tuesday...otherwise
little in the way of lower-level cloudiness expected.

Winds: Southwest winds around 5kts with seabreezes near 10kts both
this afternoon and again Tuesday afternoon with overnight winds
calm/light-variable.

LLWS:  No LLWS is expected through Tuesday Night.

Lightning: No lightning is expected through Tuesday 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...Winds/seas stay below SCA criteria through Tuesday
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.

&&

$$

AVIATION...Arnott