466
FXUS61 KGYX 231955
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
355 PM EDT Thu May 23 2024

.SYNOPSIS...
A cold front will exit east of the region tonight. Drier air
arrives Friday with mostly dry weather into Saturday. A frontal
system brings chances for showers late Saturday into Sunday. A
more organized system approaches for early next week bringing
better chances for widespread showers late Monday into Tuesday.
An upper level trough crosses the region Wednesday into Thursday
with more scattered showers.

&&

.NEAR TERM /THROUGH TONIGHT/...
The area of focus over the next hour or so will be the area of
strong to severe thunderstorms heading for the Maine Midcoast
with SPC Mesoanalysis indicating around 1500 J/kg of CAPE and 30
kt of effective shear. This supports hail the continued threat
of hail in excess of 1" in diameter and damaging wind gusts
up to 60 mph, and the Severe Thunderstorm Watch continues for
Sagadahoc, Lincoln, Knox, and Waldo counties. Areas to the north
and west where the line has already moved through, the Watch
has been canceled although can`t rule out a stray shower or
storm. There may also be some development farther south into
Cumberland, York, and Rockingham counties where outflow
interacts with the seabreeze, but the threat for thunderstorms
is expected to be over for the most part by 6 pm, with a couple
of showers remaining possible through sunset.

The rest of the night will be quiet as drier air continues to move
in behind the front. Skies will become mostly clear, and with winds
being fairly light have gone a little cooler for lows with most
being in the 50s, but northern areas may be able to reach the upper
40s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Mostly dry and warm conditions are store in for Friday with an
overall drier airmass, especially early in the day. By the late
morning and afternoon, a mid-level trough swings through
southern Quebec and sends another frontal boundary through
northern New England. Moisture is very limited, so not really
expecting much in the way of shower activity, except for in the
western ME mountains where the moisture profile is a little more
conducive (still only 20- 30% there). Temperatures are forecast
to reach the upper 70s to mid 80s across the area, except a
little cooler along the coast. Deep mixing will bring down
higher winds from aloft, which will support breezy conditions at
times to around 20-25 mph, possibly up to 30 mph on occasion.

Northwest winds carry in drier air Friday night behind the front
with high pressure building in from the north. Skies will become
mostly clear, and with winds being fairly light, have blended in
some cooler MOS guidance to account for radiational cooling. Aside
from southern NH staying in the 50s, most should see lows in the
40s, but northern valleys could reach the mid-upper 30s, which could
yield patchy frost if temps do manage to get this chilly.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
A significant transition of the trends in the synoptic regimes
and therefore the long range portion of the forecast begins this
weekend. For the overview, a trend towards cooler with more
showers expected as we head into next week.

We begin on Saturday where a west to northwesterly flow both
at the surface and aloft will start out the day with dry and
chilly conditions. A very narrow ridge of high pressure will
then cross the region under mainly sunny skies during the day.
In the afternoon, expect winds to become onshore near the
coastline.

A very weak trough will cross the region Saturday night into
Sunday bringing a few scattered showers into the region. Any
precipitation will be light and brief in duration. Latest models
and ensemble solutions suggest the most breaks in the cloud
cover will be over southern New Hampshire where temperatures
may top out in the lower 80s. Much cooler conditions are
expected over eastern portions of our forecast area.

On Monday, a large scale upper level and surface low will cross
the Great Lakes. This in term will allow for an increasing south
to southeasterly gradient to develop over the forecast area in a
warm air advection pattern. Increasing moisture will allow for
scattered showers to become more widespread Monday night into
Tuesday. It will remain on the seasonably cool side with
temperatures mainly in the 60s. Seasonably cool and showers
conditions will close out the middle to the end of the week next
week with as a significant cold pool rotates over our region.
The cold air aloft may allow for a snow shower or two to mix in
over the top of Mount Washington by the end of the week as we
approach and enter June.


&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Short Term...Most showers storms will exit/diminish by 22-23Z
this evening, but the higher potential for TEMPO restrictions
will be at RKD and possibly AUG. Mainly VFR tonight, but patchy
fog could impact LEB/HIE/AUG overnight. VFR expected on Friday
with any showers looking to remain north of the TAF sites, and
VFR is expected to continue Friday night.

Long Term...Showers will arrive Saturday night and into Sunday
with a higher potential for more widespread rainfall and flight
restrictions early next week. 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...Winds and seas are expected to remain below SCA levels
through Friday night. A few storms may move offshore into early this
evening ahead of a cold front that will shift winds to westerly
through tonight. Winds become more out of the SW late Friday morning
and then more southerly ahead of another weak front that is forecast
to cross the waters late in the day. Winds will turn more northerly
Friday evening and continue out of the north or northwest through
Friday night.

Long Term...A northwest flow Saturday night will switch to out
of the south on Sunday and continue through Monday and Tuesday.
The gradient flow and winds will increase out of the southeast
on Tuesday into SCA conditions.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$

NEAR TERM...Combs
SHORT TERM...Combs
LONG TERM...Cannon