588
FXUS61 KGYX 101038
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
638 AM EDT Thu Oct 10 2024

.SYNOPSIS...
An upper low just north of New England will continue showery
weather today but mainly in the mountains. High pressure builds
in Thursday night through Friday. A cold front crosses Saturday
morning with brief high pressure building back in late Saturday
into Sunday. An area of low pressure crosses Sunday night into
Monday bringing widespread precipitation to the region. Cooler
and showery weather follows into the middle of next week.

&&

.NEAR TERM /TODAY/...

635 AM Update...Shortwave trough has now pushed off to the east, and
the subsidence behind it allowed cloud cover to quickly diminish
south and east of the mountains. I have updated sky cover to account
for these mostly clear skies along with the usual matching up
temperatures and dewpoints to reflect current observations. We`re
starting to see some showers toward the International Border as
another wave approaches from the north.

Previous...

An upper low is currently centered near far northern ME as of
early this morning. A shortwave trough rotating around this low
is currently about to push offshore of southern NH, and the
light shower activity that has been present the last few hours
there has largely diminished. Behind the passage of this trough
axis, cloud cover south of the mountains will continue to
decrease early this morning.

For the rest of the day, precip chances will be largely
confined to the mountains and points to the north and west with
upslope flow in place...even seeing an uptick in activity this
afternoon as another shortwave dives to the south and east
across the region. The higher elevations could even see some
very light snow accumulations, possibly an inch or so at the
highest peaks. I can`t rule out a rain shower or two making it
downwind of the mountains into the foothills with Froude numbers
forecast to exceed 1 this afternoon (and with forecast
soundings also showing a small amount of low-level instability).

With this low-level instability and the shortwave moving through, I
have gone on the higher side of guidance on cloud cover this
afternoon south of the mountains with skies expected to be partly to
mostly cloudy. Good mixing will bring down higher winds from aloft,
and gusts out of the northwest of 20-30 mph are expected from late
this morning and into this afternoon. Cold advection will limit
highs to the 50s south of the mountains while the clouds keep
northern areas cooler and limited to the 40s for highs.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
Winds will lose the gustiness this evening as we lose daytime
heating, but they`re expected to remain elevated enough to keep
the low levels more mixed. Even though skies are expected to
become mostly clear south of the mountains overnight, the winds
staying up should largely prevent good radiational cooling and
fog/frost formation. Overnight lows will be mainly in the lower
40s, but more sheltered locations could still reach the mid-
upper 30s if the winds are able to drop off. If this is the
case, these sheltered locations may see patchy frost. Low-level
upslope flow will keep the mountains mostly cloudy with a chance
of showers...and then snow showers in higher elevations.

For Friday, stacked low pressure slowly moves across the Canadian
Maritimes while a mid-level ridge will extend from the Great Lakes
into western Quebec with low-level high pressure becoming centered
over the Mid-Atlantic states. This maintains northwest flow, which
will again become breezy once mixing commences by mid-late morning
with gusts of 20-30 mph into the afternoon per forecast soundings.

For the mountains and areas north and west, mostly cloudy skies are
forecast to continue through the morning, but these should start to
diminish through the afternoon with some drier air arriving.

South of the mountains, no precipitation is forecast, but there will
still be enough moisture present for some diurnal cumulus to
develop...although much less than today. More sunshine and warming
aloft with mixing to around 850mb supports highs reaching mostly the
low-mid 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A cold front will cross the region Saturday morning followed by high
pressure building in late Saturday into Sunday. The upper level
pattern will start to amplify with an area of low pressure tracking
across New England Sunday night into Monday. A cooler a breezy
pattern follows in the wake of the low pressure Tuesday into
Wednesday with the mountains seeing periods of rain and snow
showers.

Saturday will be mostly sunny and breezy in the wake of a cold front
that crosses in the morning. The core of the colder airmass lags
behind the cold front leading to high temperatures south of the
mountains into the 60s. Highs across the north will be in the
50s. Sunday will start off mostly dry while an area of low
pressure develops over the Great Lakes. This low will track
east spreading precipitation into the region from west to east
Sunday afternoon. Low pressure deepens Sunday night as it tracks
over the forecast area with widespread precipitation likely.

There are some timing and track differences in the area of low
pressure Monday. Ensembles generally suggest that precipitation
will likely continue through much of Monday with ensemble means
bringing at least a half inch of rain to the area. Low pressure
will continue to deepen Monday night into Tuesday as lifts
northeast into the Canadian Maritimes. Upslope flow in the wake
of this system will maintain chances for rain and snow showers
in the mountains into the middle of next week while areas south
of the mountains see a drying trend. Temperatures will likely
run below normal for the first half of next week.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Short Term...Cloud cover is expected to keep fog potential at a
minimum early this morning, but the most likely flight
restrictions will occasional MVFR ceilings at HIE and LEB
through today and tonight. Other sites are expected to remain
VFR today and Friday with low-end VFR ceilings possible this
afternoon. Fog potential tonight/early Friday again looks low
due to cloud cover. As far as winds, northwest winds expected to
gust 20-25kt this afternoon and then subsiding this evening.
Winds pick back up mid-late morning Friday with gusts out of the
northwest again 20-25 kt.


Long Term...Mainly VFR Friday night into Sunday morning. The
exception will be KHIE where upslope clouds and showers may
bring periods of MVFR Friday night. Low pressure crosses the
region late Sunday and Monday with MVFR likely and periods of
IFR in low cigs and rain.

&&

.MARINE...
Short Term...Northwest winds will occasionally gust 20-25 kt
this afternoon, but the gradient will further tighten this
evening with weak low pressure to the east and high pressure
building in from the west. Gusts look to be in the 25-30 kt
range over the outer waters starting this evening and continuing
through tonight and early Friday before gradually diminishing
Friday afternoon.

Long Term...Offshore winds will prevail over the waters through
the period. These winds will gust 20 to 30 kts along the outer
waters bringing an extended period of marginal SCA conditions.
Seas will generally be around 3-4 feet, although period of 5 ft
seas are possible along the far outer waters.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
     Friday for ANZ150.
     Small Craft Advisory from 2 PM this afternoon to 8 PM EDT this
     evening for ANZ151-153.
     Small Craft Advisory from 8 AM this morning to 8 AM EDT Friday
     for ANZ152-154.

&&

$$

NEAR TERM...Combs
SHORT TERM...Combs
LONG TERM...Schroeter