Sandown, New Hampshire Weather Forecast Discussion

502
FXUS61 KGYX 251746
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
146 PM EDT Thu Sep 25 2025
.SYNOPSIS...
Beneficial wetting rainfall will persist through this evening as
low pressure tracks across western New England. High pressure
builds back into the area by Friday and into next week with
pleasant weather expected.
&&
.NEAR TERM /THROUGH TONIGHT/...
Currently, New England is located in between modest ridging
over the Atlantic and a compact shortwave trough extending down
through portions of the Great Lakes and Ohio Valley. At the
surface, low pressure will continue to organize over western New
York before slowly moving into our area as the day progresses.
A warm front also extends east from the low and is draped near
the Massachusetts/Vermont/New Hampshire border.
An initial impulse is currently moving across New England and has
led to widespread light to moderate rain showers along and north of
the warm front through the early part of the day. As the low
continues to move east northeast the warm front will also lift
north through the day, leading to more widespread and heavier
rain showers. RAP soundings also suggest the potential for some
modest elevated instability (100 to 400 J/kg MUCAPE) over
southern New Hampshire and western Maine by this afternoon and
this evening. Thus, some embedded thunder is not out of the
question across these areas. If enough instability can be
realized, shear would be sufficient for a stronger storm or two.
Not much has changed regarding our thoughts of rain totals through
tonight. NBM 48-hour rainfall probabilities for over an inch remain
high across most of New Hampshire and western Maine but the highest
probabilities for 2 inches or more are generally over the southern
third of New Hampshire (with the exception of the White Mountains
which have some higher probabilities) and coastal areas of Maine,
bleeding into the interior a bit. Long story short, widespread
totals of an inch or greater still appear likely with some
areas of 2 inches or greater across the south. Isolated areas of
3+ inches are not out of the question if some heavier
showers/storms can train over some of the same areas. As the low
continues to move east northeast, a trailing cold front will
move across the region tonight. Most of the rain will diminish
behind front but cyclonic flow aloft may lead to some lingering
light showers into Friday.
With plenty of cloud cover and widespread rain, temperatures will
remain fairly cool today with highs mainly in the 60s (maybe some
lower 70s over southern New Hampshire and coastal Maine). Tonight`s
lows will mainly be in the mid 50s to mid 60s. Finally, given
diminishing winds and recent rainfall, some fog will also be likely
across much of the area tonight. Winds may stay just elevated
enough along the coast to keep fog minimal.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Friday will likely start out with plenty of clouds and some
lingering showers but we should see a gradual clearing trend
through the day as a secondary cold front moves through and high
pressure starts to nudge in. Highs will be warmer, mainly
ranging from the lower 70s north, to the lower 80s across
portions of the south and the coast. Given the west northwest
flow, a few showers will remain possible over some of the higher
terrain in the afternoon. Given recent moisture, light winds
will likely lead to the usual valley fog Friday night. Lows will
be a bit cooler, mainly ranging from the 40s north to the 50s
south.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Overview: After a much needed soaking rainfall, an extended return
to dry weather is expected Saturday through much of the upcoming
week. This weekend will feature above average temperatures before
more seasonable temperatures return by the middle of next week.
Impacts: No significant weather related impacts are expected
other than continued drought conditions.
Forecast Details: The forecast will begin on a warm note with sfc
high pressure overhead with h925 temperatures hovering around
+16C on Saturday. There could be some increase in high altitude
clouds late in the day across southern areas due to an offshore
stationary front but otherwise skies will be mostly sunny with
high temperatures into the 60s across the north with middle to
upper 70s south. These temperatures are around 5-10 degrees
above avg. Saturday night will feature partly to mostly cloudy
skies with low temperatures into the 40s and 50s from north to
south.
Sfc high pressure will drift to our east on Sunday with
southwesterly WAA return flow developing. This will help to push
high temperatures into the upper 70s to near 80 degrees south of the
mtns under partly to mostly sunny skies. Lows Sunday night will be
into the 40s and 50s with dry conditions persisting. A weak sfc cold
front will cross from the north on Monday with little sensible
weather impacts as highs once again approach the 80 degree mark for
many locations south of the mountains. More seasonable temperatures
then look to return towards the middle of next week behind a
secondary cold front as Canadian high pressure builds overhead.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Short Term...Widespread rain showers and low ceilings will lead
to widespread LIFR to MVFR categories through at least the first
part of tonight. Patchy dense fog is then possible overnight at
most locations. A few thunderstorms are not out of the question
this afternoon across the south and coastal areas, but
confidence in exact timing and location for these storms is too
low at the moment to add mention at any one specific site. Fog
will lift Friday morning and most areas should see improvement
to VFR conditions by the late morning or early afternoon. A few
showers and lower ceilings may hang around in the mountain
valleys through the day on Friday.
Long Term...Other than nighttime valley FG at KLEB, KHIE, and
KCON, mainly VFR conditions will prevail through the period
with winds less than 20 kts.
&&
.MARINE...
Short Term...Seas will build to around 5 feet today with wind
gusts also increasing to 25 to 30 knots as a front crosses the
waters tonight. Wind gusts will decrease overnight, but seas
will remain around 5 feet through early Friday. Winds start
easterly today, but swing around to southwesterly behind the
front Friday.
Long Term...High pressure will keep winds and seas below SCA
criteria through early next week. SCA conditions are then
possible towards mid-week behind a frontal passage.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 2 PM EDT Friday for ANZ150-152-154.
     Small Craft Advisory until 2 AM EDT Friday for ANZ151.
&&
$$
NEAR TERM...Hargrove
SHORT TERM...Hargrove
LONG TERM...Tubbs

NWS GYX Office Area Forecast Discussion