-- Discussion containing changed information from previous version are highlighted. --
721
FXUS61 KGYX 250319 AAB
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1119 PM EDT Tue Sep 24 2024

.SYNOPSIS...
A distant ocean storm continues to bring large waves to the
nearshore waters this evening, with dangerous rip currents
continuing. These will continue into Wednesday, but will
gradually start to lower tomorrow. A narrow ridge of high
pressure continues to build into New England through the middle
of the week, with dry weather and seasonable temperatures. We
will see a more widespread chance of showers Wednesday night
through Thursday night, before high pressure returns late week.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Update...Minor changes to reflect latest observational trends.

Previous discussion...All this statocu that developed today
outside the marine lyr should begin to dissipate through the
rest of the afternoon, and should mostly become scattered this
evening. Meanwhile the sfc extending SW from its center near
Labrador will continue to keep us dry overnight and into much of
Wednesday. However, better gradient onshore flow begins to pick
later tonight, which should allow the convergence that cause
all the clouds to redevelop in the pre-dawn hours, with at least
partly if not mostly cloudy skies by sunrise. There should be
enough rad cooling during the first part of tonight to push lows
back into the 40s most everywhere, but temps may level out at
some between midnight and daybreak.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
On Wed, we remain under the influence of the sfc high but the
more persistent onshore flow will allow for that convergence to
continue and should see the stratocu across much of the CWA,
along with the thickening mid-high clouds, and I think it will
be a mostly cloudy day across almost the entire region. It is
possible for more sun across central ME and the Capital region
in the morning though, as the convergence will be too far to
their W. The downslope on the E flow in the CT could give some
spots a bit more sun as well, as they will only be dealing with
the mid and high clouds. Highs will see increasing clouds,
although in the W zones it may end being mostly cloudy all day,
while the further E you go the better chance you have for more
sun in the morning. Cant rule out a few afternoon showers in
the mtns as the trough deepens to the E, and some WAA starts to
move in, but the bulk of the rain holds until Wed evening. Highs
will generally range from the low 60s. Highs will mostly be in
the low to mid 60s.

By Wed night, will see the secondary wave rotate around the base
of the 500 Mb low over S ON/QC, which will close it off, and
allow for sfc low to develop near Montreal by sunrise Thu. There
will be enough dynamics with this system, plus some mid-level
WAA to produce showers overnight, starting in the evening in NH
and moving into ME in latter part of the night. Could see a few
brief downpours late as well, and maybe even a period of steady
rain in the in the mtns that may start late Wed night and Thu
morning. Lows are likely to be right around wet-bulb temps and
once the rain moves in temps shouldnt change too much, with
mins in the 50-55 range.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Overview: The period will start wet as a 500mb trough dives
into the region and moves overhead Friday. It exits by Friday
night followed by height rises through the weekend. The ridge
axis looks to be centered on us Monday, before another trough
approaches Tuesday along with another chance for showers.

Impacts:
* No significant weather impacts expected.

Details: Widespread showers will be ongoing come Thursday
morning as a triple point passes through the region. Current
ensemble guidance is favoring rainfall amounts of around 0.5"
across most of the area with a plume of moisture driving PWATs
up around 1.5". This may equate to some areas of locally heavy
rainfall up to an inch. Models look very progressive as of now,
but something to always keep in mind is that storm motion can
become quite slow when an area is right under an upper low, so
the higher amounts being seen on the NAM and 12Z GFS may be
starting to catch on to this possibility. Fortunately, this will
be much needed rain after an exceptionally dry stretch so,
barring any really drastic changes, any threat of impactful
flooding should be nearly nonexistent. Overcast conditions will
keep high temperatures limited to the 60s across the area.
Showers exit the area shortly after sunset and skies begin to
clear overnight, but gradual enough that low temperatures likely
only bottom out in the 50s.

There will be just enough moisture wrapping around the low on
Friday to squeeze out a couple light showers, mainly in and
around the mountains, as the upper low slowly exits through the
day. Otherwise, high pressure begins nosing in from the north
so mostly clear skies will allow temperatures to warm into the
upper 60s and low 70s from the foothills south, and in the
mountains and points north, northerly flow and a tad more cloud
cover will keep temperatures in the low 60s. Low temperatures
Friday night will be a bit cooler than Thursday night, but
lingering clouds will keep them very similar. High pressure
takes full control for the weekend with Saturday and Sunday
featuring mostly clear skies, calm winds, high temperatures in
the 60s, and low temperatures in the upper 40s.

High pressure looks to hang on for Monday before the pattern
becomes a little more uncertain due to the fact that Tropical
Cyclone Helene will be moving inland in the southern U.S. This
will have an effect on the timing of the next trough, as
differences in global models currently show, so will stick with
the NBM low chance PoPs on Tuesday for now.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Short Term...This stratocu deck this afternoon should dissipate
by sunset, and VFR expected thru midnight or so before another
round of MVFR clouds develops, mainly in NH terminals overnight,
but will likely move into ME early Wed morning. The MVFR deck is
expected to linger through Wed before rain moves in Wed night
and conds drop to IFR or lower everywhere Wed night.

Long Term...Thursday will likely feature a mix of MVFR and VFR
ceilings as rain, locally heavy,moves through the area. Friday
morning may feature some fog but afterward VFR should be the
prevailing condition right through the weekend. Winds will be
light with gusts generally 10-15kts.

&&

.MARINE...
Short Term...5-6 ft seas will continue into Wednesday, and will
likely do so through Wed night, but may need to expand SCA back
to E then.

Long Term...Max wave heights of 5ft remain through at least
Friday morning before finally dropping below 5ft later in the
day and remaining below SCA criteria through the weekend. Winds
will be gusting 15-20 kts on Thursday and Friday before high
pressure begins to move over the waters and calm them a bit for
the weekend.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT Wednesday for ANZ152>154.
-- End Changed Discussion --

&&

$$

NEAR TERM...Legro