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155
FXUS61 KGYX 190251
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1051 PM EDT Tue Jun 18 2024

.SYNOPSIS...
High pressure will settle east of New England through much of
this week, continuing our period of hot and humid
conditions. Record high temperatures and potentially dangerous heat
index values are likely. A few scattered showers and thunderstorms
are possible on Wednesday. A weak cold front will slowly cross
through the region on Thursday and Friday with an increasing chance
for scattered thunderstorms and cooler temperatures by this
weekend.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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1045 PM Update...Little to no change to the going forecast as a
warm, mostly clear, and calm night is expected along with some
patchy fog and haze.

710 PM Update...Partly cloudy skies are the rule early this
evening and that will continue into the overnight. Isolated
showers and or thunderstorms will come to an end with the loss
of daytime heating in an hour or two. Otherwise a warm and muggy
night continues to be in store.

Previously...

Any leftover scattered showers and thunderstorms and Cu fields will
diminish after sunset across portions of the region this evening.
This will set the stage for a mainly clear and calm night with the
exception of any leftover high level debris clouds moving
across the region from time to time.

A fog bank did form along the Downeast coast of Maine last night per
latest satellite photos. This maritime moisture may redevelop once
again and potentially push as far west as the Midcoast region. While
this likelihood is not overly high, will just mention it for
consideration in later updates.

It will be a mild night with just about all areas dropping back into
the 65 to 70 degree range. Patchy fog will develop during the late
night and early morning hours.
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&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
The heat is on as the upper level ridge becomes fully established
over the Northeast. Used a blend of guidance to arrive at mid to
upper 90s across much of the region on Wednesday. Even coastal zones
will be hazy, hot and humid just a few miles from the shoreline.
Coolest areas, albeit still hot, will be across the higher
terrain and along the immediate shoreline where winds will
become onshore during the day.

Scattered showers and thunderstorms will occur once again. This time
around, precipitation will be possible anywhere across the forecast
area.

Patchy fog develops once again Wednesday night. A very mild night
can be expected once again with many areas remaining in the lower
70s as dew points will be on the high side.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Relief is in sight, but we`ll have one more day in the very hot
stretch of hot and humid weather to contend with. Temperatures
are again forecast to soar into the 90s across the area, and
with dewpoints remaining in the upper 60s to lower 70s, heat
indices are forecast to again reach the 95 to 105 degree range,
possibly exceeding 105 degrees in some areas. A frontal boundary
will also slowly sag southward through the area during the day
with westerly flow likely enough to hold off the sea breeze,
bringing these hot temperatures all the way to the immediate
coast. This will likely prompt a continuation of heat headlines
through the day on Thursday over portions of the area.

The hot and humid conditions will also provide instability for
showers and storms to develop as the front moves through, and
some of the storms could be strong to severe with strong to
damaging winds as the primary hazard. It`s possible there may be
some hail as well, but freezing levels will be quite high.

It will be still be warm on Friday, especially over southern
NH, but will be much more manageable than the temps today-
Thursday with the post-frontal air coming in. Highs are forecast
to be in the mid- upper 80s for southern NH and the low-mid 80s
for the rest of the area. There will also be a tight moisture
gradient with the higher moisture across NH and this area has
30-50% chances for showers while chances decrease to the north
and east.

Although still running above normal for this time of year,
temperatures will follow a cooling trend over the upcoming
weekend as heights lower, flow aloft becomes more zonal, and
more in the way of clouds are expected. In addition to this,
dewpoints will also come down into the 50s for most of the area
on Saturday (except lower 60s in southern NH) before creeping
back upward into the 60s on Sunday. Highs on Saturday are
forecast to be in the upper 70s to lower 80s, and these may
increase by another couple of degrees by Sunday as southerly
flow starts increasing ahead of a cold front. This is certainly
good news after the hot weather this week. There is another
chance for shower late Saturday into Saturday night as energy
aloft moves overhead, but due to confidence have stuck with NBM
of 40-50% at this time.

A better chance for more widespread precip and possibly a few
storms arrives late Sunday and into Monday as a more potent
upper trough pushes a cold front through New England. Assuming
the front pushes through as advertised (decent agreement in the
models this far), we should see drying conditions by next
Tuesday or so.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Mainly VFR condition with the exception of a brief
shower or thunderstorm this evening across the north and west.
Patchy fog with localized IFR conditions. VFR tomorrow with the
exception of an isolated shower or thunderstorm.

Long Term...Mainly VFR outside of precipitation Thursday. A
cold front will be pushing through the area on Thursday, and
scattered showers and storms could bring brief MVFR to IFR
restrictions. For, Friday and Saturday, precip chances look
lower overall, but the better chances will be across the NH
terminals. A cold front approaches Sunday into Monday with
chances for widespread precip and restrictions.

&&

.MARINE...
Short Term...Winds increase out of the south to southwest
gusting to 20 kt tonight through Wednesday night, just below SCA
thresholds.

Long Term...A weak frontal boundary approaches from the north
on Thursday with winds out of the southwest to west out
initially, but these will shift to the N/NE Thursday night
behind the front. Conditions are expected to remain below SCA
levels. However, will have to watch for offshore-moving showers
and storms on Thursday. Broad high pressure remains over the
waters Friday and Saturday before southerly flow potentially
exceeds SCA levels Sunday into Monday as a cold front
approaches.

&&

.CLIMATE...
Record breaking high temperatures and warm overnight low
temperatures are likely Tuesday through Friday of next week.

Here are the records...

RECORD HIGHS FOR JUNE 19: Concord-98, 1995 Augusta-98, 1995 Portland-
94, 1995

RECORD HIGHS FOR JUNE 20: Concord-98, 1993 Augusta-95, 1953 Portland-
93, 2020

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
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ME...Heat Advisory from noon to 8 PM EDT Wednesday for MEZ007>009-
     022>028.
     Excessive Heat Warning from noon to 8 PM EDT Wednesday for
     MEZ012>014-018>021-033.
NH...Heat Advisory from noon to 8 PM EDT Wednesday for NHZ001>003-
     005-007-011-014.
     Excessive Heat Warning from noon to 8 PM EDT Wednesday for
     NHZ004-006-008>010-012-013-015.
MARINE...None.
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&&

$$