099
FXUS61 KGYX 281224 AAA
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
824 AM EDT Fri Jun 28 2024

.SYNOPSIS...
High pressure brings fair weather today into Saturday morning.
Low pressure tracking east across Quebec will lift a warm front
into the area late Saturday bringing rain. A cold front then
cross Sunday for continued chances for showers and thunderstorms
with locally heavy rainfall. High pressure builds in from the
west Monday bringing mostly dry conditions into the middle of
next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
825 AM Update...Dropped SCA given diminishing winds across the
coastal waters this hour. No other changes attm.

630 AM Update...Minor update to T/Tds to align with observed
trends. Otherwise, no changes to the going forecast for today.

Previously...

High pressure centered over Lake Ontario will slide east across
New England providing fair weather today. Northwest winds will
be breezy this morning before relaxing this afternoon as the
high moves closer to overhead. Highs will range from the upper
60s north to the upper 70s across the south.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
High pressure moves into the Gulf of Maine tonight and will
gradually move east into the Atlantic during the day Saturday.
Return flow around the high and an approaching trough will
advect warmer air and moisture into the region leading to
increasing clouds tonight into Saturday morning. This will lead
to lows mainly in the 50s.

The approaching trough will lead to low pressure developing over
the Great Lakes Saturday morning with this low tracking ENE
across Quebec into Saturday night. This low will lift warm
front into New England late Saturday with showers breaking out
from west to east Saturday afternoon. The 00Z model suite is in
good agreement that instability will remain south and west of
the area through 00Z Sunday limiting the chances for convection.
PWATs will be on the rise Saturday afternoon approaching 1.75
to 2.25 inches by Saturday evening north to south. These high
PWATs combined with building elevated instability will bring the
threat for heavier rainfall Saturday evening into Saturday
night with more details below in the long term section.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
7am Friday Update: Overnight trends showing a decreasing heavy
rainfall signature for Saturday night...though locally heavy
rainfall rates are still likely given ample PWAT values and warm
cloud depths...with focus turning more to an increasing
conditional threat of severe thunderstorms by Sunday late
morning and afternoon. SPC has added a slight risk to the
southeastern half of the forecast area with a marginal risk
elsewhere. Biggest question mark at this range is timing the
cold front...and thus southeastern areas have the greatest
potential for significant destabilization ahead of the arriving
boundary in an area of ample 0-3km and 0-6km shear. Primary
hazard threat looks to be damaging winds with llevel shear
orientation favoring bowing line segments where convection
develops. Have added mention of this potential to the Hazardous
Weather Outlook and we will look to refine the details on where
instability will be sufficient to warrant what could be a
significant severe weather threat.

Previous Discussion below...
An unsettled weather pattern returns for the weekend. Low
pressure tracking across Quebec will help a warm front and an
eventual cold front through the area Saturday night and Sunday.
Rain and chances for convection will be in store Saturday night
before tapering to showers by daybreak on Sunday. There will be
plenty of moisture to work with so locally heavy rainfall is
possible during this period. Attention will be paid to the
position of the frontal boundary and track of the surface low,
which could support a swath of heavy rain. WPC has the area in a
marginal risk with the window of concern late Saturday night
through daybreak Sunday. On Sunday an upper level trough
approaches the area which will help to initiate scattered
showers and thunderstorms throughout the day. A few showers may
linger into Monday as the upper level trough crosses the area
although most of the day should be dry. As the upper level
trough enters the Gulf of Maine indications are that low
pressure will form. However, models continue to show the area of
low pressure forming east of the area which will keep any
additional showers offshore and allow high pressure to build
eastward from the Ohio Valley Tuesday and Wednesday bringing dry
and seasonable conditions to the area.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR prevails today with a period of NW winds
gusting 15-20 kts from mid morning until early afternoon before
relaxing later this afternoon. VFR likely prevails tonight into
Saturday morning. Clouds thicken and lower Saturday morning into
the afternoon with -SHRA developing west to east Saturday
afternoon. This will likely introduce periods of MVFR at KHIE
and KLEB between 18Z Saturday to 00Z Sunday.

Long Term...Numerous showers and thunderstorms with locally
heavy rain Saturday night into Sunday morning will result in
sub-VFR conditions.

&&

.MARINE...
Short Term...Winds subside later this morning as high pressure
moves in with winds and seas staying below SCA thresholds this
afternoon into Saturday morning. Low pressure tracking northwest
of New England will bring increasing southerly flow Saturday
with winds and seas approaching SCA thresholds Saturday
afternoon.

Long Term...Small Craft Advisory conditions probable as
southerly flow increases ahead of a cold front Saturday night.
Showers and thunderstorms may produce locally gusty winds.

Monday...The conditions are anticipated to be below Small Craft
Advisory criteria as winds subside, however some choppy seas
could approach 4 ft on the outer waters.

&&

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

&&

$$


NEAR TERM Update...Arnott