363
FXUS61 KGYX 190736
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
336 AM EDT Thu Jun 19 2025

.SYNOPSIS...
Warm and muggy conditions are expected today before a cold
front approaches the region this evening. The cold front will
bring higher chances for showers and thunderstorms, some of
which could be strong to severe. Friday and the weekend will be
drier, with windy conditions likely Friday. A few showers or
thunderstorms cannot be ruled out through the weekend. Hot and
humid conditions will then return early next week.

&&

.NEAR TERM /THROUGH TODAY/...
Nighttime microphysics satellite imagery early on this Thursday
morning shows a plethora of low-level stratus over much of the
region with water vapor imagery also showing some higher level
clouds above the stratus deck. ASOS/AWOS visibility
observations show that areas of fog are containing to develop
across the region with some locations down to 1/4SM. Therefore,
the Dense Fog Advisory for much of coastal ME will be allowed to
continue through 8AM and will continue to monitor trends for
the need of any expansion in area. Northeast radar mosaic shows
some isolated showers developing over VT and especially over
southern Quebec and some of this activity will likely drift into
northwestern ME over the coming hours. Current temperatures are
primarily into the 60s and little in the way of additional
cooling is expected through sunrise.

Latest HREF guidance indicates that the low-level stratus and
fog should burn off fairly quickly this morning over NH and
extreme southwestern ME but it may linger through much of the
day towards the Mid-Coast Region and Penobscot Bay. This
clearing will allow for temperatures to quickly respond with
forecast highs around 90 degrees in southern NH with lower to
middle 80s elsewhere. The coolest readings will be towards the
Mid-Coast and Penobscot Bay where the lingering cloud cover will
limit highs to the 60s and 70s. No changes have been made to the
Heat Advisory in portions of interior southern NH as this is
where heat indices could approach 95 degrees for a few hours
this afternoon.

The main story for today continues to be for the potential of
strong to severe thunderstorms late this afternoon through this
evening as a deep H5 trof axis moves east from the Ohio River
Valley this afternoon before arriving here in New England this
evening. At the surface, closed low pressure over Southern
Quebec will send a sfc warm front northward this morning,
placing our region within the warm sector, and then a trailing
cold front will cross late this evening. The added forcing for
ascent combined with MLCAPE values around 2,000 J/KG, 0-6km bulk
shear between 30-40 kts, and 0-3 km lapse rates around 7C/km
will introduce the threat for locally damaging winds along with
severe hail. While not the primary threat, right turning
hodographs combined with low LCL heights, 0-1km shear around
25-30 kts, and 3CAPE over 100 J/KG introduces a non-zero threat
for an isolated tornado. There has been little change in the
latest SPC D1 outlook with just a subtle shift of the SLGT Risk
(level 2/5) back towards the east some. A MRGL Risk (level 1/5)
persists across the Seacoast of NH and along the ME coastline up
to around Rockland and then east of there only general thunder
is forecast. High PWATS of near or over 1.50" also suggests a
low-end flash flood threat.

In terms of timing, latest hi-res guidance continues to indicate
while a few discrete cells could develop late this morning or
afternoon the main batch of showers and storms likely won`t be
approaching the CT River Valley until between 3-5PM before
moving eastward into western ME by 6-9PM and then exiting
eastern portions of the CWA by midnight or so. For area of
greatest concern, latest hi-res guidance and HREF paintball
probability tracks indicate a region extending from south-
central NH and then up through the western ME foothills and
mountains will be the focus for storm coverage. That being said,
there is quite a bit of run-run variability and anywhere stands
a chance of seeing a storm.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
The cold front will sweep across the region tonight, bringing an
end to the severe threat. A few lingering showers/thunderstorms
could persist though. Southerly flow will become westerly by
daybreak while increasing some with overnight lows mostly into
the 60s.

A rather strong pressure gradient for late June will exist on
Friday, which combined with deep mixing will allow for a breezy
day. Westerly wind gusts up to around 40 mph or so are likely
with falling dew points through the day back into the
comfortable 50s. Highs will range from the 60s across the north
to around 80 south. A few showers are possible, mainly across
the mtns.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
12am Long Term Update...Latest guidance continues to depict a
hot start to next week, and have kept temperatures mostly in
line with day crew`s thoughts. Made some modification to PoPs
through this weekend, mainly improving temporal resolution to
incoming rain Saturday night. Showers taper Sunday morning with
west winds shifting SW into Monday with WAA.

An expansive upper ridge across the Deep South extending well up
into the Great Lakes will gradually build toward New England and the
Eastern Seaboard over the weekend bringing a warming trend. There`s
still uncertainty on chances for showers and storms over the
weekend, although there is arguably a little better agreement in
timing of wave(s) riding into the area on the eastern periphery of
the ridge with the higher PoPs favoring Saturday night and into the
first half of Sunday at this point. However, there is still quite a
bit of uncertainty in the location.

Going into early next week, confidence remains high in the
strong ridge further expanding toward the area and bringing the
hottest temperatures of the year so far, which will also come
with increasing humidity. Monday and Tuesday could both feature
heat indices reaching the mid to upper 90s across portions of
the interior with most precipitation staying north of the
region. There is more uncertainty on whether it will remain as
hot going into next Wednesday with more spread in the guidance
as a front may approach from the north and weaken the ridge.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Short Term...Low-level stratus combined with areas of FG will
continue to result in IFR to LIFR restrictions through daybreak.
Conditions will quickly improve to VFR by or shortly after 12Z
at NH TAF sites before arriving at KPWM within an hour or so
either side of 16Z. It will likely take until early to mid-
afternoon at KAUG to improve and KRKD may remain at IFR through
much of the day. Winds will be out of the south at 10-20 kts.
Scattered SHRA along with TSRA is then likely after 20Z through
around 02Z Friday. A few +TSRA are possible with strong winds
and hail. The greatest threat for +TSRA will be across inland
TAF sites with a lesser threat at KPSM, KPWM, and KRKD. Showers
and storms will become isolated tonight and ceilings may briefly
linger before drying westerly winds increase after midnight
with improving conditions. VFR is then mostly expected on Friday
with westerly wind gusts up to 30 kts.

Long Term...There will be a chance of showers and storms over the
weekend with guidance favoring Saturday night into Sunday of
having the higher potential. However, confidence is low on
location(s). By early next week. expecting mostly VFR.

&&

.MARINE...
Short Term...SCA conditions are expected tonight through much of
Friday as southerly winds become westerly behind a strong cold
front with gusts up to 30 kts and seas of 3-6 ft over the outer
waters and 1-3 ft in the bays.

Long Term...Conditions generally remain below SCA levels over
the weekend as high pressure builds across the waters and then
becomes centered south of the waters. South to southwest flow
persists early next week, and there some indications a front may
approach from the north late Tuesday or Wednesday, which could
tighten the pressure gradient and increase winds across the
waters

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Dense Fog Advisory until 8 AM EDT this morning for MEZ024>028.
NH...Heat Advisory from noon today to 7 PM EDT this evening for
     NHZ012-013.
MARINE...Small Craft Advisory from 8 PM this evening to midnight EDT
     Friday night for ANZ150.
     Small Craft Advisory from 4 AM to 8 PM EDT Friday for ANZ151-
     153.
     Small Craft Advisory from 8 PM this evening to 8 PM EDT Friday
     for ANZ152-154.

&&

$$

NEAR TERM...Tubbs
SHORT TERM...Tubbs
LONG TERM...Combs/Cornwell