515
FXUS61 KGYX 181030
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
630 AM EDT Sat May 18 2024

.SYNOPSIS...
Low pressure moving up the East Coast will spread light showers
into Maine and eastern New Hampshire today. High pressure
strengthens over the region early next week with dry conditions
and well above normal temperatures. Scattered showers return by
late Wednesday into Thursday as a cold front approaches and
then crosses the region. An upper level trough will keep
scattered showers over the region Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...
Latest radar imagery and mesoscale models continue to
show moisture arriving from the Gulf of Maine in the form of
showers this morning. This precipitation will continue to
retrograde from the coastal waters to much of our forecast area
during the day and into this evening. Have upped pops for this
morning to likely over the southern half of the forecast area.
Otherwise, just minor edits to the surface dew point,
temperature and wind forecasts.

Seasonable temperatures today and Sunday will be replaced by a
large ridge of high pressure and increasingly warm temperatures
next week.

Prev Disc..
Mesoscale models continue to bring scattered showers in off the
Gulf of Maine today around the periphery of an exiting trough
of low pressure well southeast of our coastal waters. A second
weakening trough will also approach from the west today. Most
global models are now coming around to the chance of showers
today, especially along and near the coastline. Will keep chance
pops in the forecast for this morning, increasing to likely
this afternoon. Confidence in the arrival of precipitation will
continue to increase as bands of precipitation shown on latest
composite 88D reflectivity imagery retrograde towards the
coastline this morning.

There will be plenty of clouds in all areas today with the
marine layer moving in off the Gulf of Maine. This onshore flow
will keep the coastline on the chilly side with upper 50s and
lower 60s and will allow for patchy fog early. Across the
interior, it will be warmer with afternoon highs reaching the
mid and upper 60s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Pops will be highest along the coast this evening before
diminishing overnight as high pressure attempts to reassert
itself over the region. Plenty of clouds will remain as well as
patchy fog with the soupy maritime environment continuing.
Overnight lows will be fairly uniform over the region with
mainly readings in the mid 40s to lower 50s.

Sunday will be a rain-free day. A moist northeast flow will
continue to bring clouds to the region, especially over southern
and eastern portions of the forecast area. The most sunshine
will be in New Hampshire. Western New Hampshire will be warming
up with lower 70s expected in the Connecticut River Valley. The
coolest portion of the region will continue to be the Midcoast
which may remain in the 50s for highs.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
...A significant warm up is still on its way for next week
especially across the interior where temperatures well into the
80s can be expected...

Overview: Two main pressure systems will influence conditions
over the area through the long term. First will be high pressure
that maintains quiet weather overhead for the second half of
the weekend and into early next week. Second is approaching low
pressure and trough that could bring a round of widespread
rainfall to the area as well as the chance for some
thunderstorms into midweek. Temperatures are forecast to rise
for early in the week, perhaps by 10 to 15 degrees above normal
for southern portions of the area.

Details: Ridging sits over the area Sunday with more stable
conditions. While precipitation isnt expected, there will
remain moisture in the low levels that is expected to leave much
of the area cloudy. Cant rule out drizzle considering some of
the profiles looking saturated in the low levels, but any sort
of lift is limited as well. Will hold off on drizzle wording for
now, but would expect at least some patchy drizzle into the
morning and perhaps again in the evening. These conditions will
leave temperatures mild, but went slightly lower than the mean
considering the chance for cloud cover. Some breaks will be
possible on western side of the mountains, particularly in the
afternoon, so left expected highs here closer to the mean (upper
60s to around 70). With clouds expected to remain overnight,
lows are also mild falling to around 50.

Moisture layer will have thinned by the time Monday rolls
around, and currently forecast thinning clouds into the
afternoon. This should be a good start to a warming trend for
early next week with highs pushing into the mid to upper 70s.
The warmer temps arent expected until Tuesday/Wednesday when
return flow from exiting high really combines to push 850mb
temps above 10C.

Well above normal temperatures are possible Tuesday and
Wednesday next week. The area will be in between weather
systems, with high pressure sliding east and incoming trough
from the west. This should emphasize SW flow through much of the
column, resulting in good WAA. This would mean temps pushing
into the 80s for at least southern areas. NBM probabilities hint
at temps perhaps exceeding 85 degrees up the CT River Valley
and interior southern NH, but areal extent outside of those
locations isnt consistent.

Another topic for mid week will be the return of forcing,
moisture, and instability. Surface low pressure is forecast to
track up towards James Bay by Wednesday night, with an
associated warm front lifting through the region and cold front
exiting the eastern Great Lakes. This will create some favorable
conditions for rounds of showers, but also some thunder. There
remains differences in guidance to hone in on exact
timing/impacts, but can say the environment will be more
unsettled here especially on the heels of the warm/hot
conditions. The front should pass off the coastal waters towards
Friday morning, with slightly cooler temps into next weekend.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Fog will dissipate this morning, but ceilings will
also be lowering so improvements may only be made to MVFR. This
will be the case through the day before skies only partially clear
overnight Saturday. Again there will be a chance for localized
fog, but ceilings will be trending toward VFR for Sunday.

Long Term...Ceiling restrictions expected Sunday, with mainly
MVFR and some IFR for much of the area. These remain overnight
into Monday morning, but begin to improve towards VFR into the
afternoon. Low confidence in fog/vis restrictions at this time,
but can`t rule out drizzle Sunday. VFR conditions Tues into Wed,
perhaps some overnight valley fog.

&&

.MARINE...
Short Term...SCA conditions will continue as low pressure
moving over the eastern waters pushes 5 ft swell into the area
with winds not exceeding criteria. These elevated seas look to
last through Saturday night and begin subsiding Sunday morning.
Winds will be primarily northeasterly through this period with
gusts around 15-20 kts.

Long Term...Wave heights remain around 5 ft Sunday, but will be
decreasing overnight into Monday as high pressure takes up
residence. This should lead to sub-SCA impacts to wind/waves,
but could also see some fog over water develop as warmer
temperatures enter the region into early next week.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 10 AM EDT Sunday for ANZ150-152-154.

&&

$$
Cannon