Atkinson, New Hampshire 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

104
FXUS61 KGYX 041343
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
943 AM EDT Wed Jun 4 2025

.SYNOPSIS...
A ridge of high pressure slides over the Northeast today
providing dry weather while skies will be hazy from elevated
wildfire smoke. Heat and humidity builds Thursday ahead of a
slow moving cold front that will bring chances for strong to
severe storms Thursday afternoon. The front will linger near New
England Friday into the weekend with waves of low pressure
bringing daily chances for showers and storms. High pressure
briefly builds in early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

940AM Update...No big changes with a warm day still ahead, but
hourly temperatures are running a little behind what the forecast
had, probably as a function of the filtered sunshine with the
elevated wildfire smoke across the area. Refreshed the hourly temps
to align with more obs, and forecast highs have been lowered by a
degree or so.

650 AM...Minor update to T/Tds to capture the latest round of
observations.

Previously...

Mid level ridge axis will slide overhead today with T8s climbing
to around +17C this afternoon. Mixing to around 850 mb will
allow for highs to climb well into the 80s across much of the
area. Onshore winds will help keep coastal areas cooler this
afternoon. Latest HRRR integrated smoke runs indicate that
skies will be hazy for much of the day due to elevated wildfire
smoke with the haze starting to clear west to east this
evening. These hazy skies may hold high temperatures back from
reaching their full potential. Mixing will help keep dewpoints
into the 50s so heat indices will not be much different that
ambient air temperatures.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
It will be mild tonight as the mid level ridge breaks down and
slides east. Lows will range from the mid 50s to low 60s across
the area.

Temperatures and humidity will become pronounced Thursday ahead
of a slow moving cold front that approaches from the northwest.
Highs will climb into the low 90s south of the mountains and
away from the immediate coast. Deep moisture will advect into
the region with dewpoints climbing into the mid to upper 60s
that will bring heat indices to near Heat Advisory thresholds
south of the mountains and away from the coast.

The humid airmass will allow for enough instability for
thunderstorms to develop Thursday afternoon into the evening
with the highest chances from the foothills northward. The 00Z
HREF mean brings MU CAPE to near 2000 J/kg with a corridor of
effective shear to 25-30 kts sinking southward through the
mountains. The best forcing with the approaching front looks to
remain near and just north of the Canadian border. This lack of
forcing and some mid level dry air may limit thunderstorm
coverage Thursday afternoon into the evening and have capped
coverage to scattered wording. The juxtaposition of modest shear
with moderate instability will likely be enough for a few
strong to severe storms that will be capable of producing
damaging winds and severe hail. The latest outlook from SPC
brings a Marginal Risk for severe storms across much of the area
away from the coast with both 5 percent probabilities for
damaging winds and severe hail.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Long term forecast update...01z NBM has been blended into the
going forecast. Not too many changes in store other that to
lower PoPs a bit for showers and thunderstorms as forcing for
ascent lags to the west.

Previously...

The front remains in the picture Friday and Saturday with rain
chances remaining high along with a few storms during this
period as waves of low pressure move along it. The front is
expected to lift back north, but models continue to struggle in
how far and where the axis of the higher rain totals sets up.
The last couple runs of the operational GFS have trended much
farther north with highest QPF just north of the area while the
12Z ECWMF is pretty much right over and ME. Digging a little
deeper, the ensembles from the GFS have higher probabilities of
over an inch just over the border into Canada while the ECWMF is
right over the forecast area. So needless to say, amounts
remain uncertain as well as where the higher rain totals will
end up being.

Regardless of where the front sets up and what path the low takes,
there is pretty good consensus of these being east of the area going
into Sunday. This will bring a drying trend, although there could
still be a few lingering showers, especially if the upper trough is
yet to cross. Global models are then advertising another system
approaching early next week, but Monday may stay dry depending on
the speed of the system, but it looks like chances for showers
return by Monday night or Tuesday.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Mainly VFR today into Thursday. Some elevated
wildfire smoke will produce hazy skies while visibility
restrictions are not expected. Increasing moisture tonight may
allow for some marine fog to push into the coast, while
confidence is not high enough to put in the TAF. There will be
chances for isolated to scattered storms Thursday afternoon and
evening that will likely bring restrictions if a TS is able to
track over a TAF site. The greatest chances for TS Thursday will
be from KLEB to KCON to KAUG and points northward.

Long Term...Thursday night, could see IFR to LIFR due to fog
and low stratus with improvement through Friday morning.
Additional rounds of showers/storms are likely later in the day
Friday through Saturday as the front remains across the region,
but details are uncertain. Sunday should start seeing drying and
improving conditions.

&&

.MARINE...
Short Term...High pressure remains centered south of the waters
today through Thursday with winds and seas remaining below SCA
thresholds. Increasing humidly may allow for fog to develop
over the waters Thursday into Thursday evening.

Long Term...A cold front is expected to linger somewhere over
the area Friday into Saturday, but it`s still uncertain where it
will set up and where the low pressure will track ...which will
determine the wind direction/speed. However, chances for SCA
conditions are looking low. The system exits to the east Sunday
into Monday as high pressure builds back in. Another system may
approach the waters around next Tuesday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Air Quality Alert from 11 AM this morning to 11 PM EDT
     Thursday for MEZ023>028.
NH...Air Quality Alert until midnight EDT tonight for NHZ013-014.
MARINE...None.

&&

$$


NEAR TERM...Combs/Schroeter
SHORT TERM...Schroeter
LONG TERM...Combs