442
FXUS61 KGYX 130625
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
225 AM EDT Sun Jul 13 2025

.SYNOPSIS...
An airmass with high humidity over the area will linger today.
There is a chance of a few showers or a thunderstorm during
peak heating this afternoon and early evening. A cold front will
near the region on Monday with widespread showers and
thunderstorms, some of which could produce locally heavy
rainfall. Drier weather returns Tuesday, with heat and humidity
building in for the rest of the week.

&&

.NEAR TERM /THROUGH TODAY/...
Nighttime microphysics satellite imagery early this Sunday
morning shows a plethora of low-level stratus over most of the
region south of the mountains. These low ceilings are resulting
in fog in many locations, some of which has become locally
dense. Fog and reduced visibility will prevail through this
morning along with patchy drizzle at times. Current temperatures
are primarily into the 60s and little in the way of additional
cooling is expected through sunrise.

Today will feature another overcast and foggy start to the day
before clouds begin to scatter out late morning and into the
afternoon across northwestern ME and interior NH while the
stratus deck lingers a few hours longer over southwestern ME
south of the foothills along with the Seacoast of NH. High
temperatures will range from the 70s over much of western ME
with lower to middle 80s in interior NH. A few scattered showers
and storms are possible during the afternoon and evening, mainly
from the mountains and points north. These could produce locally
heavy rainfall but the overall hydro threat is low due to the
isolated coverage that is expected.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
The H5 s/wv ridge axis will begin to drift east tonight ahead of
an area of low pressure and associated cold front to our west.
At the surface, onshore flow will prevail, leading to
additional low ceilings and fog. Scattered showers and rumbles
of thunder will remain possible across the mountains and towards
the Canadian Border but most other locations should remain dry.
Low temperatures will be mainly into the lower to middle 60s.

Low pressure lifting northeast through Quebec will drag a cold front
across the area Monday. The airmass ahead of the front will be
moisture rich with dewpoints nearing 70 degrees and ensembles
showing PWATs approaching 2 inches. The front and mid level support
will be weakening upon approach, although look to be enough to
trigger scattered thunderstorms across the area with the highest
PoPs during the afternoon. Deep layer shear will be modest around 30
kts across northern zones with shear diminishing south of the
mountains. The best juxtaposition of shear and instability looks to
remain north and west of the area while model soundings suggest that
there could some strong to marginally severe storms across
northern zones with CAMs showing a weakening trend as storms
slowly track SE into the coastal plain Monday night.

Given the recent isolated heavy rainfall experienced across SW New
Hampshire within the present airmass, the greater impact from
thunderstorms on Monday will be the threat for torrential rainfall.
Multiple ingredients look to be in place with PWATs nearing +2SD and
deep warm cloud depths greater than 12kFT. In addition, flow
looks to be parallel to the frontal boundary with small Moe
velocity vectors. This would support slow moving storms and the
potential for training. Both the 00Z HRRR and NAMnest suggest
storms will be capable of rates approaching 1-2 inches per hour
and any training of these rates will bring the risk of flash
flooding. Otherwise, Monday will be mostly cloudy and humid with
highs in the 70s to mid 80s. Onshore flow and stable marine air
will limit the threat of thunderstorms along the coastal plain.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Messages

 - Steamy hot/hazy summer days starting Tuesday

 - Mainly hit/miss (30%) thunderstorm chances mid-late week

Once the frontal passage clears the area there will be a brief
drop in humidity going into Tuesday. There will be plentiful
sunshine which will allow temps to rise into the upper 80s to
low 90s for most areas. The expansion of the summertime upper
ridge and the Bermuda high will dominate the weather across much
of the east coast for much of the work week. This pattern will
favor a return to summertime hot and hazy days. A progressive
zonal flow regime late week will likely bring scattered showers
and thunderstorms, but timing of these weak features is
difficult this far out. Have stuck with the typical diurnal risk
windows in the afternoon until conditions become clearer.
Overall, Tuesday looks to be the best chance for dry weather,
while Friday could see more widespread showers and storms as
another surface cool front approaches.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Short Term...Low ceilings and FG will continue through around
12-15Z today before scattering out to VFR/MVFR later in the
day. KRKD may remain at IFR though through much of the day.
Scattered SHRA/TSRA is possible after 16Z at KHIE and KLEB.
Winds will be out of the south at 5-15 kts. Marine stratus
returns this evening and lingers through Monday morning,
bringing additional flight restrictions. Slow improvements are
then likely again later Monday before more widespread SHRA and
TSRA arrive during the afternoon and evening with southeasterly
flow. No LLWS is anticipated outside of any TSRA.

Long Term...Conditions improve to VFR under sunny skies
Tuesday. Mainly VFR thereafter.

&&

.MARINE...
Short Term...South-southeasterly flow will prevail through the
period at 5-15 kts and seas of 1-3 ft. Marine fog will continue
to be common, especially at night and during the morning and
evening hours.

Long Term...Expect similar to above through much of the work week.
Winds with the initial cold front Monday night washout out so apart
from light and variable there are no notable wind shifts. Looking at
predominant S/SW/SE winds throughout the forecast, with waves 2`
with a 7-8 sec swell.

&&

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

&&

$$

NEAR TERM...Tubbs
SHORT TERM...Tubbs/Schroeter
LONG TERM...Jamison/Schroeter