Area Forecast Discussion
Issued by NWS Portland, ME

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160
FXUS61 KGYX 251426
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1026 AM EDT Sat May 25 2024

.SYNOPSIS...
Dry today as high pressure centers itself to the south and east
of northern New England. A frontal system brings chances for
showers late tonight. A more organized system approaches for
early next week bringing better chances for widespread showers
Monday night into Tuesday. An upper level trough crosses the
region Wednesday through Friday with more scattered showers.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...
Plenty of sunshine will continue today with the exception of the
mountains where satellite imagery already indicates the
formation of Cu in the region. Some high, thin clouds will enter
the region from the west today.

Afternoon high temperatures will reach the 70s in most areas.
Along the coast, a cooling sea breeze will lower temperatures
this afternoon.

Prev Disc...
640am Update...Perhaps a bit of a milky cast to the sky this
morning. HRRR-Smoke does show some elevated wildfire smoke
passing overhead today. This isn`t expected to impact surface
conditions. No big changes this morning. Temps fell into the mid
to lower 30s across northern NH and far western ME, and some
patchy morning fog also developed.

Previous Discussion...
A fine start to the weekend today under mostly sunny skies.
Among a light breeze today, temperatures warm into the mid to
upper 70s away from the coast. The lack of low level moisture
will tend to make it feel a couple degrees cooler, but still a
seasonable day. Vast temp differential inland vs coastal waters
will induce a inland propagating seabreeze this afternoon. This
should begin to move early this afternoon, cooling coastal
locations further. This will eventually subside as daytime
heating wanes, and winds become light this evening.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Weakening front approaching from the west will offer the chance
of some showers overnight, potentially with a rumble of thunder
or two. Much of this shower coverage will be determined by how
much lasting convection there may be from the afternoon to the
west. In addition, near term guidance varies on the amount and
timing of elevated instability overnight. Thus kept slight
chance of thunder for overnight, before a break through Sunday
morning.

Sunday is forecast to have temperatures a few degrees warmer as
a front becomes stationary just south or over southern NH. This
will help act as forcing for the chance of additional shower
development Sunday afternoon. With greater heating and moisture
in the region, would also expect isolated thunderstorms to
develop. Some hires guidance (inc RAP/NAMnest) paints a
parameter space that would be conducive for stronger storms, but
areal coverage looks limited further from the front. At this
time, there has been a trend for this to be focused towards
southern NH. Potential impacts would be small hail, increased
wind gusts, and heavy downpours that may slowly train over
locations. These chances dwindle into the evening hours.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
5/24 12Z models and ensemble solutions continue to indicate a
more robust system will approach the region on Monday. This may
bring a chance for a shower in the morning as low pressure
intensifies and enters into Canada bringing a warm front towards
New England. An area of more widespread precipitation will
enter the region from the west during the rest of the day
Monday. Models however remain in disagreement as to the timing
of this rainfall. In any case, the highest pops will arrive
Monday night as a band of increased moisture arrives ahead of an
approaching cold front. Sufficient instability may allow for an
embedded thunderstorm as well. Some of the precipitation may be
locally heavy, especially across upslope regions of the
mountains. PWs will be running as high as 1.5 inches as deep
moisture rides up the coastline.

On Tuesday, drier air will works it way into the region on
westerly winds aloft. Some sunshine will allow for temperatures
to climb to warmer conditions than Monday with temperatures
topping out in the 70s with lower 80s in southern New Hampshire.

For the period Wednesday through Friday, a slow moving, upper
level trough will approach and then cross the region. This will
bring scattered showers to the region, especially after daytime
heating during the afternoon hours. Temperatures will be
seasonable for this time of the year.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Short Term...VFR. Just cirrus passing today as dry low levels
prevent another deck from developing. Sea breeze will cause a
wind shift at coastal terminals beginning around 18z. Overnight
will see thickening and lowering of clouds, but remaining VFR
with a few patches of MVFR ceilings. SHRA overnight with
perhaps some isolated TS passing through. Another round of SHRA
possible Sunday afternoon, with TS possible in southern NH
terminals.

Long Term...Higher potential for widespread rainfall and flight
restrictions arriving from west to east Monday and continuing
through Monday night. An upper level trough will bring a few
more scattered showers during the midweek period with pockets of
IFR conditions at times.

&&

.MARINE...
Short Term...High pressure centers to the south and east today,
with wind shifts expected through the day. Passing weak front
tonight will stall south of the waters, and this may focus
shower and thunderstorm development Sunday afternoon for the
area. Conditions remain below SCA, but storms Sunday could bring
small hail or gusty winds to the southern waters.

Long Term...A light southerly flow will continue through
Monday. The gradient flow and winds will increase out of the
southeast for late Monday night into Tuesday with SCA
conditions. A southerly flow will continue on Tuesday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Beach Hazards Statement until 8 PM EDT this evening for
     MEZ023>028.
NH...Beach Hazards Statement until 8 PM EDT this evening for NHZ014.
MARINE...None.

&&

$$
Cannon