886
FXUS61 KGYX 110807
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
407 AM EDT Sat May 11 2024

.SYNOPSIS...
A cool and unsettled pattern is expected through the weekend as
a longwave trough gradually crosses the area. There will be
chances for afternoon showers this weekend, with some lingering
into the evening hours. Below average temperatures are
expected, with a trend warmer into early week. A more widespread
rain is likely Tuesday into Wednesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The region remains between weather systems as low pressure
passes well off the Atlantic coast today. NE flow will keep
moist air in the low to mid levels, resulting in another chance
for light showers this afternoon. These will build out of
diurnal cu filling in across the CWA through the morning hours.
Not much change in thinking on location, but did keep isolated
PoPs in the area a bit longer into the evening. This is based on
observations the past two nights of nocturnal showers
continuing in NH, as well as HRRR/ARW depicting these ongoing
amid some convergence.

Highs today shouldn`t vary much from Friday, climbing into the
mid to upper 50s. We are still under a similar airmass, and if
it wern`t for the moisture from 800 to 900mb, it would be a very
dry day.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Another challenging forecast tonight in regards to sky condition
and thus overnight lows. While much of the initial clouds in the
evening should fade w/ loss of daytime heating, clouds Fri night
remained broken or overcast in many locations. Think tonight
will be a similar story with little change in pattern.

This means pockets that will remain warmer around 40, and other
that may cool 10 degrees further due to radiational cooling.
Current sky forecast depicts clouds thinning once again across
much of southern ME and this time more of NH. Thus these spots
will be scrutinized for their overnight lows. It`s reasonable
to say that sheltered areas under these clearing calm skies will
likely see patchy frost develop. With the Frost/Freeze program
expanding across the interior today, should confidence and areal
coverage fit, Frost headlines may be needed tonight.

Sunday will offer another chance of diurnal showers spurred on
by continued instability in the mid to low levels. Warm level
aloft retreats by Sunday, giving a deeper mixing layer as well
as the potential for slightly more CAPE. With some added
convergence due to a passing wave to the south, this evening`s
MPAS run does depict the chance for some showers to develop
graupel across northern NH and far western ME. Would still like
to see more MUCAPE above 100 j/kg however for this to be more
likely.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
An upper level trough crosses New England late this weekend,
with a welcome warming trend following its passage albeit with
some rain (although not a washout). A more organized system
brings better chances for more widespread rainfall around the
middle of next week.

Shortwave ridging moves in behind the departing upper level low
Sunday night, with rain shower chances diminishing and some
clearing. Overall it could be a good radiational cooling night
depending on the timing and degree of clearing, with lows most
likely near 40 but potentially down into the mid-30s in more
ideal scenarios. With the growing season active everywhere but
the mountain zones, will have to keep an eye on trends in case a
frost/freeze headline may be necessary.

High pressure slides offshore to the east on Monday with flow
turning more zonal aloft. Meanwhile upstream, another upper
level trough will be spinning across northern Ontario into
Quebec. Ridging should initially suppress precipitation chances,
but it is short- lived and transient so by the time we get into
peak heating/mixing we`ll start seeing pressure falls and
associated warm advection from the west. These will support high
temperatures largely in the 60s, along with diurnal rain shower
activity. With the offshore high, there ought to be a strong
sea breeze that will limit temperatures along the coast.

There is good model agreement by now WRT the aforementioned Canadian
trough bringing a warm front across New England Monday night through
Tuesday, followed by a cold front on Wednesday. This more organized
system brings better potential for more widespread rain to the area
though there`s still quite a bit of uncertainty WRT to QPF at this
range. Though, the majority of ensemble members keep totals
around 0.75" or less which doesn`t raise too many alarm bells
for hydro, however PWATs will likely rise above 1.0 inch and SW
flow parallel to the front gives some pause... so it`ll be
another item to watch trends on.


&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Short Term...VFR. Some SHRA across interior terminals today, but
these shouldn`t impact vis. Winds will also be light, with a
wind shift possible at coastal terminals amid a afternoon
seabreeze.

Long Term...VFR prevails into Mon, except brief MVFR in SHRA
possible over the interior and west. More widespread SHRA/RA and
associated restrictions are likely to develop Tue into Wed,
with VFR returning Wed into Thu.

&&

.MARINE...
Short Term...Below SCA conditions with winds generally less than
20 kt and waves 1 to 3 ft through Sunday. Lighter winds will
tend to be variable, but in general onshore flow expected today
before turning north overnight. A return to onshore is expected
again Sunday.

Long Term...Light flow and quiet seas are expected over the
extended forecast period with SCA conditions unlikely to occur.
In general, winds will turn out of the SW to start the next
week however daily sea breezes and a nebulous pressure gradient
will muddy this progression a bit. The best chance for 25+ kt
winds, right now, comes around Tue with a more organized system
potentially crossing the region which also brings potential for
rain and fog. This system likely departs around Wednesday night
with drier air filters in by Thursday, however the trough may
cut off near the coast which will impact timing a bit.

&&

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

&&

$$


NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Casey