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000
FXUS61 KGYX 241817
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
217 PM EDT Wed Apr 24 2024

.SYNOPSIS...
Low pressure moves into the region today bringing rain showers
and perhaps a few snow flakes to the mountains. Dry high
pressure then moves across the region Thursday through Saturday.
A warming trend can be expected over the weekend with chance of
showers Saturday night or Sunday. Warmer weather is then
expected early next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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2pm Update...Quick update to refresh current PoPs and
expectations for the afternoon. Primary area of showers is now
pulling into eastern Maine. Behind, nearly full sun has popped
out across southern NH and interior to coastal ME. This has
caused a quick spike in temperatures into the mid to upper 50s,
with a couple 60 degree readings sprinkled in mainly in southern
NH. With this good surface heating and incoming cold front,
expect some convective showers to develop which are now entering
from western NH. Upstream obs have been pretty gusty, with a
number supporting 30 to 35 mph gusts at times. These could
linger into the evening hours considering the cooler air aloft
moving in. Again can`t dismiss a few rumbles of thunder in
southern NH or far southern ME, along with any deeper showers
potentially containing graupel.

1030am Update...Near term forecast looks okay this morning. As
new data comes in, made some changes to afternoon, mainly for
winds and afternoon shower coverage. Faint fineline in MRMS
comp radar through Montreal this morning is bringing gusts to
35 mph. This is set to make its way south through the area along
with passing cold front this afternoon. Upped wind gusts for a
few hours this afternoon to align with this front passing.
Looking at HREF probabilistic momentum transfer, gusts 25 to
35mph look most likely, but can`t rule out some gusts around 40
before the sun sets. There will also be a brief window of
instability ahead of the front that, once prompted by lifting,
could develop deeper showers and possibility of a couple rumbles
of thunder later in southern NH. CAPE values are slim, not much
more than 200 j/kg, so will be conditional on any further
surface heating through early afternoon.

630am Update... Have upped the pops this morning as some areas
were reporting very light rain as of 10Z despite plenty of dry
air initially in the latest soundings. Showers will continue
through at least early this afternoon before drier and colder
air arrives later in the day. Minor adjustments to temperatures,
dew points and winds for the near term portion of the forecast.

Prev Disc...
A cold front will cross the region today with an
upper level short wave crossing the region during the midday
hours. Models continue to be in relatively good agreement
developing a weak area of low pressure along this system.
Showers will cross western Maine and New Hampshire with the
highest pops over the northern mountains.

The precipitation may end as a brief period of snow across the
higher terrain this afternoon. Little accumulation is expected.
Strong cold air advection and an increasing gradient will allow
for gusty winds towards the later portion of today. Afternoon
highs will generally be in the 40s north to the 50s in the
south.
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&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Gusty winds expected tonight with GYX probabilistic data plots
suggesting wind gusts in excess of 25 kts. Clearing will
continue as a large ridge of high pressure builds into the
region from Canada. It will be chilly with lows in the upper
teens north to the 20s south.

Much less in the way of wind is expected for Thursday as the
ridge builds over northern New England. Highs will once again
reach the 40s in the north to the lower to mid 50s across the
south under mostly sunny conditions.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Overview: A large dome of high pressure builds over the eastern
CONUS Thursday through Saturday. This will result in warm days
and cool nights under partly to mostly sunny skies. High
pressure then moves to our east by early Sunday as a weak
frontal boundary arrives from the west, resulting in an
increased chance for scattered showers Saturday night through
part of Sunday. Showery conditions at times along with warm
temperatures look to continue through early to mid next week.

Impacts: Low afternoon RH is likely on Friday with values
falling into the teens to 20s percent range. This will be in
combination with west-northwesterly wind gusts up to around 25
mph, which could result in increased fire weather conditions.

Forecast Details: Surface high pressure will build over the
eastern CONUS on Thursday through Saturday, resulting in warm
days and cool nights. Thursday night will feature mainly clear
skies along with light winds, which will result in good
radiational cooling conditions. Therefore blended in raw MOS
guidance into the overnight forecast, which brings some interior
valleys down into the teens to near 20 degrees with middle 20s
to near 30 degrees elsewhere. Friday will feature partly to
mostly sunny skies with warm afternoon temperatures into the 50s
to middle 60s from north to south. Westerly winds up to around
20-25 mph combined with afternoon RH into the teens to 20s
percent range could result in increased fire weather concerns
but it will otherwise be a nice day.

Another night of radiational cooling is then likely Friday night
under mostly clear skies and light winds. Lows will range from
the 20s to lower 30s. Light winds and warm temperatures will
prevail on Saturday with highs into the 60s in most locations.
The weak flow will likely result in a sea breeze though, which
would keep the coast cooler given current SSTs. Clouds will
increase by Saturday night with perhaps a few scattered showers
by dawn as a front approaches from the west. Scattered showers
and mainly cloudy skies are then likely on Sunday as the frontal
boundary remains near the region. It does not look like a
washout though and latest ensemble guidance suggests light
rainfall amounts. Despite the clouds it will remain warm with
perhaps a few 70 degree readings over southern NH depending on
cloud cover.

Depending on the placement of another frontal boundary, some
showery weather will remain possible at times through the first
half of next week but rainfall looks to remain on the light side
with temperatures remaining mild.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Short Term...Conditions lowering to MVFR today in showers with
areas of IFR possible in the precipitation and lowered ceilings.
Conditions improve tonight to VFR and continue on Thursday
however some MVFR conditions may linger in the mountains.

Long Term...VFR prevails Thursday night through Saturday with
high pressure overhead. Scattered -SHRA arrives Saturday night
through part of Sunday with possible lower ceilings.

&&

.MARINE...
Short Term...SCAs have been issued as winds will be increasing
over the coastal waters beginning this afternoon. A few gusts
may approach gales for a short period this evening.

Long Term...Winds and seas to remain below thresholds hazardous
to small crafts as high pressure builds over the waters.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 AM EDT Thursday for ANZ150-152-
     154.
     Small Craft Advisory from 6 PM this evening to 4 AM EDT
     Thursday for ANZ151-153.

&&

$$


NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Ekster