-- Discussion containing changed information from previous version are highlighted. --
299
FXUS61 KGYX 231132
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
732 AM EDT Thu May 23 2024

.SYNOPSIS...
Very warm conditions continue through today before a cold front
moves through bringing scattered thunderstorms this afternoon.
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
bring better chances for widespread showers late Monday into
Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

-- Changed Discussion --
730AM Update...Another update to increase PoPs across the
foothills and western Maine mountains over the next couple of
hours to capture the shower activity seen on radar. Isolated
storms are possible across this area as well, and can`t rule out
small hail in the more robust cells.

635 AM...Just quick update to cover the round of showers moving
through the CWA attm. Better forcing is seen on the N edge of
the CWA, but these showers expected to move through by 13-14Z,
with perhaps a better organized line developing midday to early
afternoon.

Previously...500 MB ridging over the NE and E Canada starts to
break down today as closed low n of the Great Lakes deepens and
shifts E. A weak wave is moving into the ridge early this
morning, and that may produce a few showers, especially across
the N zones through about 12Z or so, but the main feature is the
sfc front, which is actually just NW of the CWA along the srn
ON/QC border, and it will take one surge SE to the far N zone
this morning, and another one through the CWA this afternoon,
which will have more of a push to it. So, the threat of showers
and thunder in the mtns will be there through the morning, but
the better chance across the entire the CWA will be this
afternoon.

Ahead of the front, will still see decent SW flow, and an
increase in Tds as well, so highs will be very warm again, but
lower than Wed, generally in the 80-85 range, although cooler at
the beaches, and in the mtns, where thews clouds and showers
will prevent temps from warming too much. Upper 80s are expected
in the hot spots of srn NH. Good mid level flow and 500 MB
height falls point to possible severe storms, and considering
SREF mean CAPEs this afternoon are 1000 J/kg or higher, should
see tall updrafts develop. Initial strong capping will limit
development at the start, and may limit the amount of storms
that can form, but sea breeze boundary, or leftover boundary may
help focus forcing, so this is the area to watch for
development this afternoon. It does seem like the front clear
the E zones by 00Z or a little before, so it looks like this all
should be done by sunset, if not before.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Drier air shifts in behind the front, but we may end up in a
situation, where the winds die off after sunset before a lot of
the dry air mixes down. The best for this scenario seems to be
in the ME Capital region and the mid coast, and this where there
could be some fog tonight. Of course, this is also possible in
the CT valley and some mtn valleys where decoupling will happen.
Low range from the low to mid 50s in the mtns to around 60 in
srn NH and on the ME coast.

500 MB trough axis swings through on Friday, and brings a weak
secondary cold front through, although it will have little
effect other than some clouds, and maybe a few showers in the W
ME mtns. The coolest air wont start moving in until late on
Friday, so with the downslope and the warmer air aloft, highs
will range from the mid 70s N to the low 80s S, although Tds
will be in the upper 40s to low 50s, so noticeably less humid.
Also will see W winds of 10-15 mph, so a little breezier than
the past few days.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A ridge briefly builds in Friday night and Saturday, keeping
things mostly dry along with the continued warmth. Temps again
Saturday look to reach the mid 70s to lower 80s for most of the
area.

Late in the day and into Saturday night, a weak wave aloft and
broad area of low pressure will bring another opportunity for
showers through Sunday morning, but amounts look light with
ensemble means from the GFS and ECMWF both indicating amounts in
the 0.10-0.25" range. Depending if this low remains close
enough nearby on Sunday, a few showers may again develop during
the afternoon.

Models are showing good continuity for early next week with a
low pressure system setting up over or just north of the Great
Lakes region. While they have shied away from the coastal low
scenario for the most part, a cold front looks to be sent toward
New England, bringing the next potential for widespread
rainfall across the area in the Monday-Tuesday timeframe. There
are also signals for heavy rainfall out of this system as
ensembles from the ECMWF/GFS are already showing decent
probabilities for PWATs in excess of 1.50", but we`ll watch
trends over the coming days. Another wave could follow quickly
behind the front, so there is uncertainty if next Wednesday will
be dry or not.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Short Term...For a change I get to discuss mainly VFR through
today, as we are seeing enough flow on the boundary layer to
prevent decoupling and temps from dropping to the dew point or
lower. Scattered TSRA are possible today, especially at ME
terminals, and these could cause brief flight restrictions and
strong gusty winds, but will be very hit and miss, so the odds
of seeing one at any given terminal are low. Could see some fog
tonight at KAUG/KRKD as cold front may moved through too late to
scour out the sfc moisture. Also valley fog possible at
KHIE/KLEB late tonight. VFR expected on Fri.

Long Term...Going into the weekend, with southerly flow
continuing, marine fog/stratus may impact the coastal sites, but
this is of low confidence. Additional showers also look to
arrive late Saturday and into Sunday with a higher potential for
more widespread rainfall and flight restrictions early next
week.

&&

.MARINE...
Short Term...A few SW gusts to near 35 kts still possible into
this afternoon as flow tightens up ahead of a cold front, but
winds should diminish, become less gusty and shift W behind the
front tonight, with sub-SCA conds expected through Fri night at
least.

Long Term...W/SW flow starts out Friday but will gradually
become more southerly by the afternoon. Winds will then switch
to northerly late in the day into Friday night as another
frontal boundary crosses but remaining below SCA levels. High
pressure becomes centered southeast of the waters over the
weekend leading to a prevailing southerly flow with fog possible
at times. A weak low pressure may bring some showers late
Saturday and into Sunday. Going into early next week, a more
potent low pressure north of the Great Lakes will send a cold
front toward New England with increasing south to southeast
winds potentially surpassing SCA levels late Monday into
Tuesday.

&&

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

&&

$$


NEAR TERM...Combs/Cempa
SHORT TERM...Cempa
LONG TERM...Cempa/Combs