293
FXUS61 KGYX 302230
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
630 PM EDT Thu May 30 2024

.SYNOPSIS...
High pressure building towards the region through Friday will bring
clearing skies...cool nights...and seasonable day time temperatures.
A warming trend will begin this weekend with any chances for showers
remaining minimal. These mild and generally dry conditions are
expected to persist through at least the first half of next
week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
630 PM Update...The going forecast remains on track as showers
are now well offshore. Clouds are still draped over the coastal
plain, but will be slowly clearing. Also delayed clearing up
north for a few hours as clouds are streaming in from across the
International Border. Otherwise, very minor tweaks to
temperature, dewpoints, and winds just to load in observations
and smooth trends over the next couple of hours.

Previous Discussion...
High Impact Weather Potential: Frost
potential across the north...otherwise minimal.

Pattern: Compact shortwave responsible for this morning shower
activity across southern areas is pushing east as broader longwave
troughing settles overhead.

Through this Evening: Residual shower activity will quickly come to
an end this evening as northwesterly flow advects drier air into the
region.  Expect skies to continue to clear from the northwest with
8pm temperatures ranging from the mid 50s north to around 60 in the
south.

Tonight: With low pressure departing to the east...drier
northwesterly flow becomes established for the overnight which
should bring clearing skies to the entire area as advertised by
short term mesoscale ensemble guidance. 1000 mb geostrophic wind
speeds remain about 20kts through the overnight which suggests that
the hilltops should remain coupled overnight while the deeper
valleys go calm. In these valleys...Thursday PM dewpoints will have
fallen into the 30s /even upper 20s/ which should allow temperatures
to fall quickly. Previous forecast followed the MOS guidance closely
and see no reason to deviate from this trend.  The result will be a
frosty night across our northern tier of zones and will hoist a
frost advisory for this expectation.  Further south...most other
locations will fall into the lower and middle 40s...warmest on the
hills.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
High Impact Weather Potential:  Minimal.

Pattern: Longwave trough axis just to our east early Friday will
continue to push east through the short term period with a longwave
ridge building in from the west. This will perpetuate dry...
northerly flow across the region with our primary forecast focus
being on whether we can spawn any showers Friday afternoon.

Friday: While mid level heights gradually build during the day...the
core of the height rises actually passes southwest of our
region...into the Mid Atlantic. At the same time...the cold core
aloft /T5s around -25C/ will brush us as it crosses eastern
Maine. This will result in some weak instability /100-200 J/kg/
of SBCAPE though with rather dry boundary layer conditions
/inverted V/ as surface dewpoints will likely be in the upper
30s. A few of the mesoscale ensemble members have a few light
showers developing in the afternoon though any of the activity
is very light. Given the dry boundary layer conditions...have
some doubts that this will materialize...and will go no higher
than a 20% PoP over our far eastern zones in the afternoon as
most locations will likely remain dry. Deep mixing is
expected...with T8s around +6-8C and some downslope assistance
expect highs in the upper 60s in the mountains to the
lower/middle 70s to the south and east.

Friday Night:  Surface high pressure ridge axis overhead with mid
level ridging building into the region from the west should allow
for a quiet night with column drying allowing for any evening mid
level cloudiness to clear out with another clear and cool night
expected. Boundary layer moisture is slightly higher than on
Thursday night with Friday`s temperatures a bit warmer than
Thursday`s.  Therefore...despite the good radiational cooling
conditions...expect that we/ll not be quite as cool as on Thursday
night...but some northern valleys will likely again drop into the
upper 30s.  Otherwise...40s north to around 50 south/coast looks
good for overnight lows.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
A rather quiet weather pattern in the long term with moderating
temperatures.  Next chance of widespread showers will hold off until
late next week.

In the dailies:  On saturday high pressure will build south of the
region off the Southeast Coast. On Sunday a weak warm front will
lift north.  This may bring a period of mid to upper level clouds
but moisture appears to be limited.  High pressure establishes
itself overhead Monday and Tuesday. The high pushes offshore on
Wednesday as low pressure moves to the Western Great Lakes. As that
low moves into Southern Canada on Thursday, a cold front will pivot
around the low and approach the region during the day.  This will
result in an area of showers and possible thunderstorms later in the
day and beyond. Have added patchy marine fog each night
starting Monday Night.

High temperatures will range from the 70`s to lower 80`s with
seabreezes cooling immediate coastal areas and islands. Low
temperatures will moderate from the upper 40s to low 50s Sunday
morning to the mid 50s to around 60 by Thursday morning.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Short Term...

Summary: Generally quiet weather is expected through the period
with clearing skies this evening behind departing low
pressure...with high pressure then building towards the region
through Friday night.

Restrictions: VFR attm across the terminals and this will dominate
the period through Friday night.  There is some limited potential
for some fog at HIE tonight...but confidence in occurrence is not
high enough at this time for inclusion in the TAF.

Winds: Northerly winds 5-10kts today will diminish to 5kts or less
tonight before rebounding to around 10G15kts from the northwest
for the day on Friday. Winds will go calm/light-variable again
Friday night.

LLWS: LLWS is not expected through Friday night.

Lightning: Lightning is not expected through Friday night.

Long Term...

Expect VFR to MVFR throughout the period.

&&

.MARINE...
Short Term...A few gusts 20-25kts will continue off the NH
coast for another couple of hours before diminishing. Beyond
this...northwesterly winds 5 to 15kts through the period will
allow both winds and waves to remain below SCA levels through
Friday night.


Long Term...Wind and waves to remain below SCA conditions
through the extended forecast period. Patchy fog mainly at night
starting Monday Night.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Frost Advisory from 2 AM to 8 AM EDT Friday for MEZ007>009.
NH...Frost Advisory from 2 AM to 8 AM EDT Friday for NHZ001>003.
MARINE...None.

&&

$$

UPDATE...Baron
NEAR TERM...Arnott
SHORT TERM...Arnott
LONG TERM...Lulofs
AVIATION...Arnott/Lulofs
MARINE...Arnott/Lulofs