Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 251034
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
634 AM EDT Tue Jun 25 2024

.SYNOPSIS...
Low pressure will move away from the area today allowing for
very warm temperatures on a breezy westerly wind. Wednesday will
be dry for most of the day as well and continued quite warm.
Low pressure will bring another round of showers and perhaps
a few thunderstorms Wednesday night with somewhat cooler and
drier air arriving for the remainder of the work week. Another
front arrives this weekend with another chance for showers and
thunderstorms.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM Update...No changes to the going forecast. Valley fog
will burn off early this morning.

Previously...

Low pressure will continue to move away from New New England
today with a dry and warm air mass taking its place. Went with a
blend of MOS output for highs today which jives with forecast
soundings yielding maxes well into the 80s in most areas with a
few 90 degree readings possible across southernmost zones. The
seabreeze will mainly be relegated to the islands and peninsulas
today with a breezy opposing flow. Early morning valley fog
across western NH will lift quickly early this morning after
sunrise, but could be locally dense beforehand.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Clouds will increase tonight as a weak WAA regime begins to take
shape. Forcing for ascent may be just enough for a few showers
overnight, and have handled this with slight chance to low
chance PoPs.

Another warm day on Wednesday with westerly downsloping winds
in place. However, clouds will increase as a short wave trough
and developing warm front approach from the southwest. Cannot
rule out a couple of isolated showers or thunderstorms late in
the day but at this time it appears the vast majority of the
region will remain dry.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
High Impact Weather Potential: Threat for widespread severe weather
is low through the long term forecast. Wednesday evening and
night...if approaching surface cold front arrives earlier than
currently expected...there would be a severe thunderstorm
threat.

--Pattern and Summary--

Unblocked pattern with multiple shortwaves embedded within the
northern stream flow indicates a fairly changeable period of weather
with strong ensemble guidance agreement on precipitation events
Wednesday night and again this weekend.  The timing of these events
will likely determine what...if any severe weather threat they will
pose. Temperatures will be above normal on Wednesday and again ahead
of the weekend frontal system...returning to around or just below
normal behind these systems.  This overall yields a warmer/wetter
than normal period.

--Daily Details--

Wednesday Night: Next northern stream shortwave arrives
Wednesday night and while the global deterministic/ensemble
guidance from the EC and GFS are are in solid agreement that
this feature will bring a round of showers and possible
thunderstorms as a cold front pushes through the area /with a
wave of low pressure potentially forming on the front/ the GGEM
ensemble as well as today/s 12Z NAM that are flatter with the
front largely coming through dry. While this spread in the
ensemble guidance suggests caution going with nearly categorical
PoPs over southern areas as shown in the NBM...feel that the
pattern overall is one that would support precipitation given
modest mid level wave and PWATs in the warm sector 1.5-1.75".
Thus...will continue forecast messaging of likelies. Timing does
not favor severe weather potential given a lack of
instability...but the kinematics will be there...so any speeding
up of the cold front could introduce severe thunderstorm
potential. The shortwave does look to move through
quickly...which limits the overall hydro threat.

Thursday through Saturday: High pressure builds into the region
Thursday as low pressure moves into the Canadian maritimes...moving
overhead Friday and then offshore for Saturday. This should provide
for a dry end to the week through at least the first half of
Saturday.  Temperatures fall back towards seasonal norms
Thursday...and even a few degrees cooler for Friday with drier
Canadian air allowing afternoon dewpoints on Friday to fall into the
40s.  Temperatures begin to rebound on Saturday ahead of the next
frontal system.

Saturday Night - Sunday: There is rather good ensemble agreement for
another frontal passage late Saturday/Saturday night.  Current
expected timing wouldn/t be conducive to a significant severe
weather threat...but residual instability and a rather impressive
moisture plume /PWATs push back above 2"/ indicates keeping an eye
on this period in later forecast for potential hydro issues.  Showers
may linger into Sunday with temperatures at or slightly above
seasonal norms.

Monday:  High pressure builds back into the region to end the
forecast period with another push of Canadian air bringing drier and
cooler conditions to end the forecast period.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Short Term...VFR conditions are expected today after early
morning valley fog in western NH burns off early on. Seabreeze
should largely be relegated to the islands and peninsulas today
but at least KRKD should see a significant onshore component
develop later on in the afternoon. VFR tonight and Wednesday.

Long Term...A cold front passing through the region Wednesday
night will bring the greatest threat for restrictions in showers
and possible thunderstorms. During this period...MVFR/IFR
restrictions are possible...with fog also possible by Thursday
morning. VFR daytime Thursday-Saturday

&&

.MARINE...
Short Term...SCA wind gusts and 5 foot seas possible tonight and
Wednesday in advance of a cold front. Temperature inversion
makes uncertainty a little higher at this time.

Long Term...The next threat for SCAs does not arrive until late
Saturday.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...Ekster
SHORT TERM...Ekster
LONG TERM...Arnott/Ekster
AVIATION...
MARINE...