649
FXUS61 KGYX 010129
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
929 PM EDT Fri May 31 2024

.SYNOPSIS...
High pressure over the Great Lakes will settle off the east coast
bringing and extended stretch of dry weather to the region with
temperatures gradually warming through the weekend. The first half
of next week is expected to continue the dry and mild stretch with
unsettled weather likely to return late next week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
0130Z Update...
Showers continue to advance and cross the the Penobscot River
Valley this evening. Latest radar imagery did show an outflow
from some of this precipitation crossing through Kennebec
County earlier. Have increased the pops over eastern areas for
the next few hours where a gusty shower remains possible in a
continuing inverted V sounding. Otherwise, only cosmetic changes
to the forecast for temperatures, dew points and winds for the
near term portion of the forecast. Isolated frost remain
possible late tonight over the northern mountain valleys with
temperatures dipping into the 30s.

Update...
Winds will subside this evening with the loss of heating.
Another cool night on tap as winds become relatively light.
Partly cloudy conditions per 22Z satellite imagery and surface
observations will become clear over the next couple hours.
Therefore, expect good radiational cooling.

Any remaining showers over far eastern sections will dissipate
shortly after sunset as well.

Prev Disc...High Impact Weather Potential: Minimal.

Pattern: Deep layer north-northwesterly flow is established across
the region with H5 low centered over eastern Quebec and Labrador and
the upstream ridge axis over the western Great Lakes. This
trough/ridge pair will only very gradually move east through
tonight.  With high pressure nearby this spells little in the way of
forecast concerns with forecast challenges centered on overnight low
temperatures.

Through this Evening: This afternoon/s robust cumulus
development and isolated shower activity will continue for a
time but should end by 8pm or shortly thereafter given waning
llevel instability. Any showers that do develop through the
evening may bring a quick gust of wind given inverted profiles
in the llevels. Temperatures at 8pm will fall back to around 60
in the mountains while sitting in the 60s to the south.

Tonight: Mesoscale ensembles painting a mostly clear night
tonight...which should again allow for good radiational cooling
conditions given very dry boundary layer conditions.  Northerly
gradient is pretty similar to last night with 1000 mb geostrophic
magnitudes around 20kts.  Last night...this allowed the valleys to
decouple with a few kts of flow remaining at coastal locations and
the hilltops /e.g. AUG/.  Expect a similar story tonight which
suggests leaning again towards the colder end of the statistical
guidance envelope. This guidance is about 3-4F warmer than last
night which...given overnight reports suggests some isolated
mid 30s...but generally temperatures warm enough to preclude
significant frost concerns and will hold off on any additional
advisories for tonight.

Beach hazard statement continues for sunny/mild/breezy
conditions with ocean temperatures still in the 50s. Fully
expect these headlines will be necessary through the weekend
given continued dry and mild conditions.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
High Impact Weather Potential:  Minimal.

Pattern: A mid level ridge axis will pull into the region from the
west as a cutoff low develops south of the Canadian maritimes.
Gradually building heights and thickness values will bring a warming
trend with dry northwesterly flow out of Canada suggesting little in
the way of sensible weather impacts.

Saturday: Dry...northwest flow aloft continues across the forecast
area for the day on Saturday as mid level low closes off over the
Canadian maritimes and shortwave ridging pulls east into PA/NY.
Boundary layer moisture look to have only increased slightly from
the day on Friday so expect afternoon dewpoints to fall into the
upper 30s given deep mixing.  At the top of the mixed layer
northwest winds of 25 to 30kts are expected...which suggests surface
based gusts of 20-25 mph.  As for high temperatures...there will be
a fairly tight thermal gradient from west to east...with T8s over NH
reaching near the 10C mark...with T8s towards AUG around
+8C. This should allow highs to crest above 80 for much of
southern NH and a few inland points in western Maine with 70s
elsewhere.

Saturday Night: Surface ridge axis will be overhead with mid level
shortwave ridging arriving from the west.  Therefore...another quiet
night with light winds is expected with the potential for some upper
level cloudiness spilling over the mid level ridge. Temperatures
should have no trouble falling into the 40s again given low
afternoon dewpoints during the day Saturday...however concurrent
warmer temperatures will keep lows a bit above Friday night/s
readings.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A rather quiet weather pattern continues in the long term. An upper
level ridge will shield the area from any significant precipitation
through most of next week.

In the dailies:  On Sunday high pressure will be centered off the
Southeast Coast. A weak warm front will lift north with a
disturbance moving along it. This feature will pass south of the
region Sunday Night into Monday. An area of mid and upper level
clouds may cross the area in association with this feature. Behind
this the east coast ridge builds back north and should dominate the
weather through midweek. Can`t rule out some scattered diurnal
shower activity mainly over the mountains and foothills but most of
the time conditions should  remain dry. A cutoff low over southern
Canada just north of the Great Lakes will have a hard time making
eastward progress. A cold front pivoting around this system
will approach Thursday and Friday increasing the chances of
showers and possibly a few thunderstorms. The GFS is more
aggressive than the ECMWF with this frontal feature. Given that
we are in a rather blocky pattern, would favor a littler slower
progression with this system so will go under GFS POPS and trend
a little closer the the ECMWF. Have added patchy marine fog
each night Monday Night through Wednesday Night.


Temperatures will be on the warm side reaching somewhat above normal
values ranging from the upper 70`s to mid 80`s Sunday and Monday and
mid 70`s to low 80`s Tuesday through Friday.  Expect afternoon
seabreezes to cool the immediate coastal areas and islands. Low
temperatures will generally be in 50`s.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Short Term...

Summary: High pressure will gradually build towards the region
through the period bringing quiet weather conditions with
moderate northwesterly winds.

Restrictions:  VFR conditions are expected to dominate through
Saturday night. There is a low potential for a rain shower at
AUG-RKD through this evening...but no restrictions are expected.

Winds: Northwest winds 10g18kts will quickly diminish to calm/light-
variable for the overnight hours. The only exception is at RKD where
a seabreeze will turn winds onshore around 10kts into the
evening. Any showers that develop this afternoon and evening
could bring local wind gusts to 30-35 mph. On Saturday...
northwest winds will again build to 10g18kts by late morning and
through the afternoon before going calm/light-variable Saturday
night.

LLWS: LLWS is note expected through Saturday night.

Lightning: Lightning is not expected through Saturday night.

Long Term...

Generally Expect VFR to MVFR throughout the
period.

&&

.MARINE...
Short Term...With high pressure west of the region...
northwesterly winds of 10-15kts are expected to continue
through the period with wave heights of 1-3 feet. This afternoon
and again Saturday afternoon...nearshore gusts will hit 20kts at
times.

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...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.

&&

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

&&

$$
NEAR/SHORT TERM...Cannon
LONG TERM...Lulofs