Windham, New Hampshire 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

466
FXUS61 KGYX 090247
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1047 PM EDT Tue Oct 8 2024

.SYNOPSIS...
An upper low descending southeast from Canada will slowly cross
the region Wednesday through Thursday bringing cooler air and
slight chances for showers at times. High pressure builds in
Thursday night and Friday. A short wave crosses northern New
England Saturday bring chances for showers and a reinforcing
shot of cooler air. Another upper low approaches Sunday and
lingers into early next week for unsettled weather.

&&

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

10:45pm Update... No major changes with this update. Brought
down lows by about a degree in radiational cooling favorable
spots east of the mountains, where skies remain clear the
longest overnight. But otherwise, the forecast remains on track
at this point.

7:45pm Update... Tweaked temps based on trends so far this
evening and cloud cover across the area and just to the west in
Vermont. No major changes with this update, but did bring temps
down slightly for tonight where clear skies allow for a good
period of radiation cooling conditions. Otherwise, the forecast
remains on track.

Previous...

Weak 500 MB wave rotating around the closed low in N Ontario.
The little bit of instability can been seen on the vis sat this
afternoon, as it has been progressing E across central and S New
England today. A lot of this is driven by daytime heating, so
expect this cu and stratocu to diminish around sunset. So, some
clearing expected early this evening, but as that wave pushes in
later this evening expecting some mid to high clouds to move in
which are currently over W NY and Lake Ontario. Initially they
will move into the N zones late this evening, and perhaps later
across the central and S zones. This sows some seeds of doubt on
tonights frost advisory, whether it will form, in the advisory
area and if it does, how widespread it will be. Given that the
clouds don;t move in until after midnight, certainly the re will
be some frost in the sheltered areas, but not sure how it will
do in coverage. Still, its out, and do expect some frost, so
will keep it as is for now. Other wise could see a few sprinkles
or even flurries in the mtns as that wave moves through late
tonight, but nothing that will cause any issues at all. Low
range from mid to upper 30s in the central and srn zones to the
low to mid 40s in srn NH and on the ME coast.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
Wednesday will see some clearing outside the mtns in the morning
as we get into some weak ridging, but the mtns will end up
partly to mostly cloudy through much of the day, and could see
a few sprinkles there as well as we see the effects of upslope
flow from the W.

Another wave dives SE across NY state and VT late Wed and Wed
night, but loses moisture once it moves away from the Great
Lakes, so any SHRA or SHSN will be limited to the mtns, where it
will get the upslope enhancement, but even these will be light
and limited through Wed night at least. Low will range from the
mid to upper 30s in the N to the low to mid 40s in the S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A relatively active pattern will persist through the long term
period as a series of troughs and upper lows cross the Northeast
bringing bouts of showers and reinforcing shots of cool air. An
upper low will lift northeastward through the Canadian
Maritimes Thursday with upslope rain and snow showers in the
mountains. High pressure builds in from the southwest Friday
before the next short wave drops southeast from Canada early
Saturday. High pressure returns late Saturday into early Sunday.
A vigorous upper low rotates through the Great Lakes late
Sunday sending a frontal system across New England Monday
followed by cooler and showery weather through the end of the
period.

A northwest gradient over New England will produce cooler and breezy
conditions Thursday. Upslope flow will produce mostly cloudy
skies and periods of rain showers along and north of the
mountains with temperatures cold enough for snow showers at the
higher summits. Downstream of the mountains skies will be partly
cloudy with NW winds gusting to 25 mph. Highs will range from
the 40s north to upper 50s south. High pressure noses in from
the SW Friday for mostly sunny skies and a warming trend.

A short wave skirting northern zones Friday night will bring
chances for showers along and north of the mountains into
Saturday morning. Areas south of the mountains will remain dry
with temperatures rising into the upper 60s for highs Saturday.
Weak high pressure crosses early Sunday with a frontal system
spreading precipitation into the area Sunday afternoon.
Ensembles suggest this frontal system will have the potential to
bring a widespread soaking rainfall Sunday night into Monday.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Mainly VFR expected through Wed night, with the
only exception being KHIE, which could see some MVFR cigs and
some showers Wed night in upslope flow.

Long Term...Mainly VFR will prevail south of the mountains
Thursday into Sunday. Upslope clouds and periods of showers will
likely lead to prevailing MVFR at KHIE Thursday into Thursday
night and again Friday night into Saturday. Persistent NW flow
will likely limit the potential for night time valley fog.

&&

.MARINE...
Short Term...Seas continue to subside over the waters, and
should drop below 5 ft overnight, with conds then remaining
below SCA criteria through Wed night.

Long Term...NW winds will gust 20-25 kts Thursday into Friday
that may warrant the need for an SCA along the outer waters.
Winds shift SW Friday night before shifting back offshore
Saturday into Sunday with gusts around 20 kts. Seas will be
around 3-4 feet and will approach 5 ft at times during periods
of stronger winds.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Frost Advisory until 9 AM EDT Wednesday for MEZ012-018-033.
NH...Frost Advisory until 9 AM EDT Wednesday for NHZ003>006.
MARINE...Small Craft Advisory until 2 AM EDT Wednesday for ANZ152-154.

&&

$$


NEAR TERM...Clair
SHORT TERM...Cempa
LONG TERM...Schroeter