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000
FXUS61 KGYX 191058
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
658 AM EDT Fri Apr 19 2024

.SYNOPSIS...
Today will feature onshore winds ahead of a cold front passage
tonight into Saturday morning. Showers form along the front,
with more widespread rain developing towards the coast early
Saturday morning. Saturday won`t be a washout. As the front
exits conditions become breezy but drier. Quiet, mild, and dry
weather remains through early next week. Low pressure approaches
the region toward mid- week, potentially bringing the next
chance for widespread rain.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
645am Update...Not many changes here but refreshing forecast w/
latest obs. There remains some uncertainty when showers begin
later; late afternoon or holding until later in the evening.
Something to look for in morning guidance. Deeper moisture for
more widespread showers won`t arrive until the evening, but
could see a couple isolated showers ahead of this make their way
over terrain into western NH late this afternoon.

Previous discussion...
Just a few remaining early morning sprinkles as upper level
vort pulls east through the morning. Mid level moisture hangs
around to make for a mostly cloudy start of the day. Can see
some breaks working in late, but will see gradual increase again
this evening ahead of incoming cold front.

Temperatures will be a few degrees cooler today, but much warmer
compared to Thursday across SW NH where the difference may be
just shy of 20 degrees warmer. Cooler spots today will be in the
higher terrain, as well as the coast. Here, cooler onshore
return flow from exiting high will keep highs topping in the
upper 40s to around 50.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
There has been a general increase in QPF/rain coverage for late
tonight into early Sat morning, particularly along the coast.
As the cold front advances, will see showers increase mid
evening and spread across the CWA. But, many short term and now
global models depict precip shield blossoming over central New
England later as front approaches the interior and coast. There
has been an ever so slight slowing trend in ensembles bringing
around a quarter inch QPF to the area before noon. This trend
hugs the coast, but can`t rule out some marginal rainfall rates
at some point into the Saturday morning timeframe for southern
NH through the Midcoast of Maine.

Saturday isn`t done yet...Oh the heels of the front departure,
expect some rather quick thinning of clouds and warming/drying
at the surface as a result. Temps across the coast and interior
to SW NH could warm readily towards 60 by early afternoon. Deep
mixing with cold temps aloft should also allow for surface wind
gusts to pick up where lapse rates steepen, possibly 30 to 40
mph.

To add to this, moisture around 850mb remains. So, the potential
for shallow convection is there for much of the area Sat
afternoon. Deeper showers that can overcome the dry air could
produce graupel given the lower freezing levels behind the cold
front and instability. Confidence is still low on coverage of
showers and potential QPF Sat afternoon given the inverted V
sounding below this moist layer.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Overview: The 500 MB pattern shows a broad trough over the
region through the weekend into early next week, however dry air
looks to dominate overhead at the same time so not much in the
way of precipitation is expected. A more amplified trough looks
to coincide with a cold front midweek, which could be our next
chance of widespread rain.

Sunday will be very similar to Saturday temperature wise, as we
start cold and clear, then continued broad troughing overhead
and southwesterly upper level flow will allow for some diurnal
cloud cover that will cap highs in the upper 50s and 40s from
south to north respectively. Upper flow then shifts westerly and
dries out the column Sunday night making for another good
looking radiational cooling night that will drop temperatures
back into the 30s. We will begin a warming trend on Monday as
upper flow becomes more zonal and skies stay mostly clear. A
cold front may dip across the international border briefly, but
with such a dry air mass aloft it wouldn`t amount to more than a
few extra clouds across the north. Highs will be back in the
upper 50s and low 60s across the south, but more 40s up north.
Clear skies will continue the trend of lows in the 30s south of
the mountains and upper 20s for northern zones that won`t be
getting as warm during the day.

Surface low pressure looks to ride the aforementioned frontal
boundary into the region toward midweek. This would mean
increasing clouds on Tuesday, but with southwesterly flow aloft
the warming trend would continue and result in many areas south
of the mountains seeing 60s and even upper 50s to the north.
Seabreezes will continue to keep coastal areas in the 50s as
well. A deeper upper trough and cold front looks to cross
Wedensday bringing our next chance for widespread rain. Euro and
GFS ensembles have only 0.25 to 0.5" at the moment so nothing
drenching, but will continue to keep an eye on trends as this is
occuring at the tail end of the extended forecast period and
uncertainty in the pattern setup is at its usual high.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR today with ceilings increasing during the
afternoon, before lowering towards MVFR tonight. Showers will
overspread the area this evening, with more in the way of
steady rain towards coastal terminals through Saturday morning.
This will likely result in a period of MVFR/IFR. Conditions
improve by Sat afternoon to VFR, but WNW winds will be gusty,
perhaps up to 30 kt at times. There is also potential for SHRA
development during the afternoon which may contain GS.


Long Term...VFR prevails from Sunday through Tuesday, before
ceilings begin to lower again Tuesday night. Prevailing winds
will be westerly through Monday, then shifting southerly on
Tuesday.

&&

.MARINE...
Short Term...Conditions remain below SCA through Saturday, but
could see some gusts to 25 kt tonight as cold front passes over
the waters Sat morning. Low level moisture may also promote
plumes of fog to develop causing low vis today in onshore flow.
Waves 2 to 3 ft.

Long Term...Westerly winds prevail with daily seabreezes
possible through Monday, before shifting to southerly on
Tuesday. Wind gusts and seas are expected to stay below criteria
hazardous to small craft through this time.

&&

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

&&

$$


NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Baron