580
FXUS61 KGYX 261055
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
655 AM EDT Sun May 26 2024

.SYNOPSIS...
A stationary front will settle across central New England today,
bringing some unsettled weather this afternoon into Monday. A
more organized system approaches Monday evening bringing widespread
showers Monday night into Tuesday. An upper level trough
crosses the region Wednesday through Friday with more scattered
showers and near seasonable temperatures.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7am Update...Showers are making their way off the coast at this
hour. Behind will be some lower clouds than we started off with
last night, but expect these to have some breaks of sun. No
changes to this afternoon`s thunder potential, but some trends
have been with lesser instability. Will keep forecast as is,
high res solutions support heavy downpours where these do
develop, on top of a Marginal risk of excessive rainfall from
WPC.

Previous Discussion...
Elevated instability combined with forcing from a weak wave will
continue rain showers early this morning. Can`t rule out a
rumble of thunder early, but showers have struggled to build
high enough to create pulses.

There will be a dry break this morning prior to building sfc
heating. Breaks in the clouds will help temps rise into the 70s
again today, with some low 80s in southern NH. These highs will
be in proximity to a stalled front left by the passing wave this
morning.

As diurnal heating takes place, convective temps will
be met and forcing along this stalled boundary should spur on
some showers and thunderstorms this afternoon, mainly for
southern NH and into the interior ME/NH lakes region. CAMs have
been fairly consistent bringing deeper storms into southern NH,
although placement and exact coverage is tricky due to the
wavering front and weak low level shear. Model soundings do
portray a good balance of shear/CAPE this afternoon, and can`t
rule out storms that feature locally enhanced wind gusts and
small hail. Backbuilding may also promote rainfall that trains,
leading to the possibility of ponding or urban flooding. On the
other side of the coin, the mid levels are quite dry, so warm
rain processes are less likely.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Surface CAPE falls off this evening, with just some elevated
instability left over to sustain weakening showers late. Onshore
flow will keep the low levels moist, and with forcing still in
the region, will likely see some isolated showers or drizzle
continue for the overnight period into Monday morning. As
onshore flow increases, would expect these showers/drizzle to
push northward through Mon morning.

Moisture depth improves Monday afternoon, and will see shower
coverage increase amid PWATs pushing around 1.5". The increased
coverage should also make for excessive clouds that limit
daytime highs to the upper 50s to around 60. Can`t rule out a
rumble of thunder early, but much of this instability may be
lost before arriving to NH/ME.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Overview: A return to a more unsettled pattern is in store for
much of next week as a series of fronts associated with upper
level lows cross over Northern New England. Temperatures will
generally be near climatological averages.

Impacts: Moderate to locally heavy rainfall is possible Monday
night as deep southerly flow interacts with an advancing warm
front. The greatest potential for heavy rainfall will be across
the mountains.

Forecast Details: Low pressure will cross into southern Quebec
on Monday night, sending a sfc warm front northward over
Northern New England. Deep sub-tropical southerly flow will help
to push precipitable water values up to around 1.50", with
NAEFS standardized anomalies approaching +2 to +3 standard
deviations. This combined with forcing from the front could
result in moderate to locally heavy rainfall overnight,
especially over southeasterly facing higher terrain due to
upslope flow. Lows will primarily be into the 50s to lower 60s.

There remains differences amongst global and ensemble based
guidance on the timing of a trailing cold front, with the ECMWF
favoring a slower arrival and thus more prolonged period of
rain into part of Tuesday while the GFS is has the front
crossing earlier in the day. Nevertheless, would expect at least
scattered showers through part of the day with highs into the
70s to lower 80s depending on how much clearing can be achieved.
Drier conditions are then likely Tuesday night with lows into
the 50s. Another front then may cross on Wednesday, possibly
resulting in additional scattered showers... especially during
the afternoon due to daytime instability. A weak area of low
pressure may then develop along this front into Thursday, with
scattered showers possible along with cooler high temperatures.
High pressure then looks to build to our west Friday through the
first half of next weekend but stalled low pressure near Nova
scotia will result in northeasterly flow and seasonably cool
temperatures.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Short Term...VFR today with SHRA early, and then again this
afternoon for southern NH terminals and parts of interior ME. TS
possible for far southern NH locations this afternoon. A trend
towards MVFR/IFR is likely this evening and overnight for most
locations outside of LEB/HIE. Drizzle and SHRA continues
overnight into Mon morning, with SHRA coverage increasing into
the afternoon.

Long Term...More widespread -RA develops Monday night into
early Tuesday with MVFR to IFR restrictions possible. Mainly
VFR is then likely later Tuesday through the middle of next
week, although patchy FG may develop at night. Winds will
primarily be out of the south-southeast with gusts nearing 20
kts.

&&

.MARINE...
Short Term...Below SCA criteria, but will see showers and
perhaps a thunderstorm on the southern coastal waters this
afternoon. Drizzle or fog may reduce visibility overnight into
Monday morning.

Long Term...South easterly wind gusts could approach 25-30 kts
Monday night into Tuesday with seas of 4-6 ft across the outer
waters and 1-3 ft in the bays. Winds and seas will then decrease
towards mid-week behind a cold front.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Beach Hazards Statement from noon EDT today through this
     evening for MEZ023>028.
NH...Beach Hazards Statement from noon EDT today through this
     evening for NHZ014.
MARINE...None.

&&

$$


NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Tubbs