418
FXUS61 KGYX 270646
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
246 AM EDT Sun Apr 27 2025

.SYNOPSIS...
An upper level low slowly crosses through New England today and
moves through the Gulf of Maine tonight, bringing rain and some
high elevation snow across the north and showers south of the
mountains. High pressure builds in Monday and Tuesday for fair
weather and temperatures in the 60s and 70s. The next frontal
system crosses Tuesday night with high pressure building in the
second half of next week.

&&

.NEAR TERM /THROUGH TODAY/...
The upper level low associated with our weekend storm system
slowly progresses through New England today. A batch of showers
is currently moving through central Maine, with a few hours of
drying behind this batch. However, as the upper level low
progresses through the area more showers develop by mid-morning.
These continue to expand into the afternoon across much of
Maine and New Hampshire. Southwestern New Hampshire is likely to
stay the most dry, but some scattered showers are still
possible here.

Across northern areas and the higher terrain, a steady shield
of rain is likely to develop through the morning and continue
into the afternoon. Temperatures continue to drop as colder air
is drawn in by the system. This brings a transition to snow by
the early afternoon hours across the higher terrain as precip
intensity increases. Accumulations will be confined to the
higher peaks, generally above 2500 feet, with a few inches
likely across the higher peaks of the White Mountains. Temps
fall back into the low to mid 30s in these areas through the
day, while mainly 40s are expected elsewhere. The relatively
warmer spots are likely to be through southeast New Hampshire
where a few low 50s are likely.

Along with the cool temperatures, west to northwesterly winds
increase by late morning, with gusts of around 25 to 35 mph
common through the afternoon hours.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
The upper level low slowly moves away through the evening
tonight. Rain likely moves offshore shortly after midnight, with
drier air arriving on northwesterly flow through the overnight.
Skies also clear shortly after the rain ends as a well defined
edge to the cloud cover moves eastward with the low`s
progression. Temperatures only gradually drop through the
overnight, with lows ranging from the mid 30s across the north,
to the mid 40s along the coastline.

Tomorrow will be a much different day than those experienced
this weekend. High pressure steadily builds in through the day,
bringing sunshine and an easing northwesterly wind. The wind
direction also keeps the seabreeze away through the day. With
this set up, temps rise into the 60s and 70s across the area.
Low 60s are expected across the north, with upper 60s and low
70s downwind of the mountains to the coast.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Late evening update...Long term forecast seems to be reasonable
with cold front moving through Tue night or early Wed, but
otherwise through Thu. Friday into next weekend is still low
confidence as run to run model consistent shows some sort of
blocked up single or double 500 MB closed low over the area, but
it`s details are still very changeable. However, if you look at
persistence to build your confidence, it would suggest a cool
and rainy weekend.

Key Message: Upper ridging to start the period will gradually
give way to more trofing over time. Heading into next weekend
the pattern will become more blocky and exactly where cutoffs
form will largely determine our sensible weather.

Impacts: No significant weather anticipated. There may be a day
or two will low dewpoints and low RH values but after a good
soaking today and enough chances for rain in the extended fire
weather is not a large concern.

Forecast Details: To start the period upper ridging and an
approaching cold front will keep winds largely from the
southwest. It is a warm pattern and ensemble guidance agrees
that Mon thru Wed should be the warmest days of the
extended...likely peaking on Tue. That looks like a widespread
70s except near the coast where winds will likely try and turn
onshore by afternoon. Southwest winds may keep it relatively
pinned to the coastline south of PWM...but sea breeze could make
a run inland across the Midcoast.

Will also be watching the timing on the front Tue. Currently
set to arrive after peak heating and instability will be
waning...but if model guidance speeds things up there may be a
need to add some thunder to the forecast. Widespread precip with
this front will be lower confidence...especially as it nears
the coast.

There is a stronger signal for precip over the weekend...as
trofing deepens over the East Coast. Initially a warm front will
lift into the Northeast and then surface low pressure will
strengthen and track thru. The GEFS and ECMWF ENS are both
pretty bullish on rain chances with the GEPS drier. Fairly
widespread likely PoP from the NBM seems fair to me at this
range...so I did not change that forecast.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Short Term...Primarily IFR conditions prevail at HIE, AUG, and
RKD today, while mainly MVFR with occasional IFR periods is
expected elsewhere. Showers continue across northern terminals,
with occasional showers likely elsewhere. Northwesterly winds
gust to around 25-30kt through the day today. VFR returns from
west to east through the evening and into the overnight hours
tonight. VFR prevails tomorrow, with northwesterly gusts around
20kt through the day.


Long Term...VFR conditions expected to prevail for most of the
period. Outside of local MVFR or lower conditions in SHRA with
the frontal passage Tue night I do not anticipate much trouble
with CIGs or VIS. Southwesterly LLJ will strengthen Tue night
but largely unidirectional flow should preclude LLWS.

&&

.MARINE...
Short Term...Low pressure continues to progress across the
waters today, and finally moves east of the waters by late
tonight. Freshening westerly winds bring continued SCA
conditions through tonight. Winds then gradually ease late
tonight and tomorrow as high pressure steadily builds across the
waters from the west.


Long Term...Marginal SCA conditions are possible Wed as a cold
front approaches the waters. The best chances are well outside
the bays. Southwest winds this time of year tend to be weaker
than forecast with the cold SSTs...so I did knock down speeds by
2-3kt and even then the seas may be too high as well.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 AM EDT Monday for ANZ150-152-154.
     Small Craft Advisory until 2 PM EDT this afternoon for ANZ151-
     153.

&&

$$


NEAR TERM...Clair
SHORT TERM...Clair
LONG TERM...Cempa/Legro