Belfast, Maine 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

010
FXUS61 KGYX 060023
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
823 PM EDT Sat Jul 5 2025

.SYNOPSIS...
Heat and humidity continue to build this weekend with shower
chances mainly confined to the mountains on Sunday. Showers and
thunderstorms are possible Monday and Tuesday as a cold front
slowly moves through the region. The front then stalls near New
England for much of the week, keeping the chance for showers
and storms each day.

&&

.NEAR TERM /THROUGH SUNDAY/...
830 PM Update... Increased cloud cover areawide from the
previous forecast as satellite imagery shows widespread clouds
continuing to stream southeastward over the H5 ridge axis and
approaching MCS feature over southern Quebec. Also increased
PoPs through the night across the north based on latest radar
trends and surface observations/webcams. While the 00Z RAOB
report shows dry air in the low-levels, there is more moisture
into the mid-levels and therefore showers are likely to develop
shortly towards the Canadian Border and mountains.

Previously...
Fairly thick smoke layer aloft has really took a bite out of
insolation today and as a result high temps are falling a little
short of the forecast. I cooled things a couple of degrees thru
the evening to account for this.

Then we have to watch decaying MCS across southern Quebec for
chance for showers tonight. Radar shows echoes crossing the St.
Lawrence currently...but little in the way of observed rainfall.
I have some isolated to widely scattered showers mentioned but I
could see it going either way. There is little if any
instability to sustain convection across the area...but as the
warm front moves in there will be sufficient forcing for ascent
and maintain some shower threat. Hi-res guidance has much of it
drying up...with what is leftover skirting parts of Somerset Co
before exiting the forecast area.

&&

.SHORT TERM /SUNDAY NIGHT/...
Main concern Sun will be the heat and humidity. Temps will climb
back into the 90s for a good portion of the area with dewpoints
surging back into the 60s to near 70. As a result heat index
values will be in the mid 90s on the lower end. A few readings
near 100 are possible. But even if we end up on the cooler side
of the forecast...a holiday weekend with lots of people outdoors
will likely lead to greater impacts and I feel a slight
expansion of the heat advisory across all of southern NH and
coastal Cumberland Co is warranted. Otherwise there were no
changes to the headline.

There also remains a conditional risk for severe thunderstorms
Sun afternoon. The warm front will remain draped across ME and
storms are possible along it. The question is whether they
actually occur in the forecast area. The threat is rather low
for our area...but if storms occur there is enough shear and
favorable enough thermodynamic profiles for gusty to damaging
winds from the stronger convection. I did not add enhanced
wording to the forecast...but will mention the conditional
threat in HWO and briefing products.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Overview...

A frontal boundary sags southward on Monday with a warm and
humid airmass in place. Relatively cooler air brings highs back
into the 80s for Tuesday and Wednesday, with scattered showers
and thunderstorms each day. The pattern then trends toward
cooler and more unsettled conditions by late in the week into
next weekend.

Details...

A warm and humid airmass remains in place again for most of the
area on Monday as a ridge remains across the Northeast. Heat
indices climb into the low to mid 90s across most of the same
areas that see the heat on Sunday, with cooler readings across
the north.

As the front sags southward, a sharp temperatures gradient sets
up with highs in the low to mid 70s toward the Canadian border
with clouds, showers, and storms. The southward progress of this
front through the day remains a variable factor, with any
further southward progress bringing cooler and wetter
conditions. Overall, there remains more uncertainty with the
Monday heat because of the front than the heat on Sunday.
Additionally, the storms that develop have the potential to be
strong with gusty winds.

Tuesday and Wednesday see the continued chance for scattered
showers and storms each day as the front lingers across New
England with temperatures warming into the upper 70s and 80s
each day.

By late in the week, a wave of low pressure likely rides along
the stalled front, bringing a better chance for more widespread
showers and storms late in the week. Additionally, moisture from
the remnants of Chantal may become drawn into this system,
increasing the rainfall potential. We`ll have to monitor the
progress of Chantal`s path and moisture plume through the week.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Short Term...Mostly VFR conditions expected thru Sun night.
Southwest breeze tonight should prevent much valley fog from
forming. Otherwise local MVFR or lower conditions are possible
but not likely in SHRA/TSRA over western ME mtns Sun afternoon.

Long Term...VFR prevails most of the time at all terminals from
Monday through Wednesday, but brief restrictions with afternoon
showers and thunderstorms will be possible at all terminals.
Chances for more restrictions increase late in the week and into
next weekend with more showers and storms developing.

&&

.MARINE...
Short Term...Southwest winds will increase on Sun. Outside of
the bays winds may gust to 25 kt and seas will build to around
5 ft. Given the relatively nice weather and busy holiday weekend
I prefer to have a SCA in effect for these conditions. Winds
and seas will diminish Sun night.

Long Term...High pressure remains centered off the East Coast
early this week. A slow moving cold front sags southward Monday
and Tuesday, stalling across the waters for much of the week.
Conditions look to remain below SCA levels as the front stalls
overhead most of the week

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from 11 AM Sunday to 8 PM EDT Monday for MEZ012-
     018>020-023-024-033.
     Beach Hazards Statement from 8 AM EDT Sunday through Sunday
     evening for MEZ027-028.
NH...Heat Advisory from 11 AM Sunday to 8 PM EDT Monday for
     NHZ006>015.
MARINE...Small Craft Advisory from 2 PM Sunday to 6 AM EDT Monday for
     ANZ150-152-154.

&&

$$

NEAR TERM...Tubbs
SHORT TERM...Legro
LONG TERM...Clair