052
FXUS61 KGYX 101139
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
639 AM EST Fri Jan 10 2025

.SYNOPSIS...
Gusty winds will gradually abate today with diminishing chances
for mountain snow showers. A clipper system will bring chances for
light snow Saturday followed by a ridge of high pressure crossing New
England Sunday and Monday. Another clipper system will cross
northern New England Tuesday that will usher in a colder airmass
for the middle to second half of next week.

&&

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

635AM Update...Just a few edits to better match up the forecast
with current observations. Most notably was again increasing
PoPs upwind of the mountains over the next few hours as the
upslope snow showers continue to outlast the mesoscale models.

Previous...

The same low pressure remains across the Maritimes early this
morning, and eastern areas have had fair amount of cloud cover
rotate in from the north and east on the backside of the low.
This should clear out within the next couple of hours, and areas
south of the mountains will go on to have a mostly sunny days as
the low pressure finally shifts east and high pressure builds
toward New England. This will relax the pressure gradient across
the region with less breezy conditions as a result. Per forecast
soundings, gusts of 20-25 mph are expected with a few
potentially crossing 30 mph. By comparison, it should feel
nicer out compared to yesterday as temperatures are forecast
reach the 30s south of the mountains.

Blocked upslope flow will keep skies mostly cloudy with a chance
of snow showers in and upwind of the mountains through this
morning. Going into this afternoon, these clouds and snow
showers will diminish as the low levels dry out with the high
building in.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
500-mb ridge will centered overhead this evening, but it will
quickly exit to the east as an upper trough approaches from the
Great Lakes. Clouds will lower and thicken from west to east
overnight as the column gradually saturates, but there will be
some lingering dry air to overcome in the low levels. So I think
most areas won`t see much in the way of snow in the tonight
period, except maybe in NH where some very light amounts may be
seen before daybreak. I have lowered PoPs slightly tonight to
delay onset by an hour or two, which is supported by trends in
latest meso models.

Going into Saturday morning, increasing lift from the upper trough
will allow light snow to overspread the area from west to east
through the day. This will be a quick-moving system, and snow
will begin tapering off across western areas going into the late
afternoon or early evening and then probably linger across eastern
areas into the evening hours.

This is expected to be of the pretty high PoP/low QPF variety
with general agreement among most models with QPF on the order
of a tenth of an inch give or take a few hundredths. The lower QPF
and the swiftness of the trough will keep snowfall amounts light,
and snow character will be drier and fluffier with SLRs higher
than 10:1 given the cold temperature profiles. Using SLRs ranging
from 15:1 to 17:1 (slightly lower ratios closer to the coast) yield
amounts of 1-2" across the board and locally up to 3" possible. One
thing to monitor is the potential for an inverted trough and
enhanced convergence along the coast. The latest 00Z and 06Z
runs of the HRRR support this and bring even higher amounts
somewhere from the Seacoast into coastal York, but as of right
now seems to be the outlier in this.

Cloud cover will decrease Saturday night as the system exits the
region, except in the mountains with a return to upslope flow.
Low temperatures expected to be the in the teens to lower 20s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
05Z Friday Long Term Forecast Update... Latest deterministic and
ensemble based guidance remains in relatively good agreement for
mostly dry conditions and relatively warm temperatures of around
to a little above average Sunday through Tuesday before turning
colder again behind a possible clipper system during the mid-
week time period. While significant uncertainty exists at this
time range, this system could bring another round of light
snowfall to the area. Otherwise, no major storm systems are in
sight.

Previously...

High pressure will build in Sunday and Monday with
temperatures averaging above normal and generally light winds.
The next clipper system will cross northern New England Tuesday
for renewed chances of snow showers. A period of gusty
northwesterly winds is likely in the wake of this clipper system
Wednesday with a colder airmass moving in for the second half
of next week.

A mid level ridge will slide across the area Sunday into Monday
for fair weather. High temperatures will range from the 20s to
mid 30s north to south with lows in the teens. A mid level
closed low will slide SE across the eastern Great Lakes Tuesday
and crosses overhead Tuesday night. This system will bring
chances for snow showers Tuesday. The 12Z model suite
suggests there will be a period of gusty winds in the wake of
this system Wednesday with colder air moving in for the second
half of next week.
 &&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
Short Term...Other than MVFR cigs and lingering -SHSN near
Whitefield this morning, VFR today and not as windy. As far as gusts
go, expecting mostly 20-25 kt but could be as high as 30 kt. VFR
most of, if not all of, tonight before a quick-moving system brings
light snow to all TAF sites Saturday. Snow looks to begin mostly
after 09-10Z tonight for the New Hampshire terminals and will spread
into western Maine closer to 12-13Z based on the latest forecast.
Ceilings are expected to lower to MVFR by Saturday morning, with IFR
possibly at times, and visibility will likely reach IFR within
-SN. Conditions improve Saturday evening into Saturday night.

Long Term...Mainly VFR Sunday into Tuesday. A weak system could
bring a little snow towards the middle of the week but
significant uncertainty remains.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Short Term...

Long Term...

&&

.MARINE...
Short Term...Gusts to gale force remain possible early this
morning over the outer waters. After that, northwest winds will
steadily diminish through the day as high pressure builds into
New England, SCA conditions will continue over the outer waters
into early this evening and also across the bays into this
afternoon. Conditions remain below SCA levels tonight through
Saturday as low pressure passes south of the waters on Saturday.
However, north winds will begin to increase again toward early
Saturday evening, potentially reaching SCA levels Saturday night.

Long Term...SCAs may be needed into Sunday morning as winds
gust to around 25 kts in the wake of a clipper system. Winds and
seas remain below SCA thresholds from Sunday afternoon into
Tuesday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 7 PM EST this evening for
     ANZ150>154.

&&

$$


NEAR TERM...Combs
SHORT TERM...Combs
LONG TERM...Schroeter/Tubbs