652
FXUS61 KGYX 310747
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
247 AM EST Fri Jan 31 2025

.SYNOPSIS...
On the heels of a very cold air mass a low pressure system will
pass to our south today. To the north of the track an area of
light precipitation is forecast to move through the region. Most
of this should fall as snow with light accumulations, but some
light freezing rain or rain may be possible across parts of
southern New Hampshire. Temperatures will then begin to yo-yo as
another cold high pressure descends on the area. Then another
warm front will lift towards the area Sunday night into Monday
with another round of light precipitation. Once again snow and a
mix is possible.

&&

.NEAR TERM /THROUGH TODAY/...
A weak stalled out frontal zone will remain to our south today
keeping clouds in our region, especially southern areas. Models
continue to suggest the advertised area of low pressure
entering the Ohio Valley will bring precipitation to the region
today, albeit, relatively late in the day for most portions of
the forecast area. Pops increase to likely by late in the day
over southern New Hampshire and York County in Maine.

Ptype...Temperature profiles suggest that a rain and snow mix
breaks out across southernmost New Hampshire near the
Massachusetts border towards evening with snow adjacent to the
north. This may impact the late portions of the evening commute.
Temperatures will be on the warm side however with mostly 30s
for highs with readings near 40 along the Massachusetts border.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
Models are in relatively good agreement in bringing a weak area
of low pressure well to our south tonight off the Mid Atlantic
coastline. The upper level flow is featured with a positively
and weak open wave that quickly crosses the region. Therefore
precipitation is expected to be on the light side. Any rain, or
the slight chance for any brief pockets of light icing will
change to all snow over southern areas during the evening.
Expect 1 to 3 inches of snow in most areas with the lightest
precipitation over the far north, furthest away from the
system.

By Saturday, sunshine will return to the Northeast on drying
northwesterly breezes. High pressure will build towards the
region from the Great Lakes, bringing seasonable temperatures
for this time of the year to Maine and New Hampshire during the
day, but with frigid temperatures returning for the beginning
portion of the long term forecast.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
05Z Friday Long Term Update... Forecast guidance continues to
indicate that after a dry day on Sunday with H5 s/wv ridging
cresting over the region, an area of low pressure will bring a
period of snow Sunday night into the first half of Monday. This
snow will likely mix with and/or end as a period of light rain
south of the foothills on Monday as temperatures warm well above
freezing. Another storm system may bring additional
precipitation chances mid-next week. Temperatures through the
period look to be near to above climo.

Previously...
Key Message: Temps will be a yo-yo between above and below
normal thru the extended. There will be ample chance for precip
over the next 7 days as well.

Impacts: Primary hazard will be wintry precip. With warm air
lurking nearby it is no guarantee that it will all be snow...so
some freezing rain or sleet will be a possibility in addition
to snow accumulation.

Forecast Details: Model guidance has a strong signal for surface
high pressure settling overhead Sat night. The question will be
whether upper ridge axis can hold off long enough to keep skies
clear. For now ensemble guidance has this over central NY...so I
opted for blending in some colder MOS and 25th percentile NBM to
the low temps Sat night. If trends stay clear it is possible
temps could fall close to cold weather advisory criteria in some
of the northern valleys.

By Sun night southwest flow will be impinging on departing cold
dome. An area of convergence and ascent is likely over the
region. Given the direction of winds in the mid levels and warm
air hanging around nearby...all precip types are potentially on
the table with this event. However models are typically too
quick to erode the cold air...even in the event that a barrier
jet does not form. I leaned colder both on temps and ptypes as a
result. This will keep it most snow for the forecast
area...except for some rain or freezing rain across southern NH
into coastal southwestern ME.

Despite the long lead time...there is a strong ensemble signal
for precip again around midweek. This one looks like it could be
warmer and track farther north. This would introduce far more
mixing...but for now given how far out this event is I kept
precip types rain or snow.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
Short Term...Widespread precipitation arrives late in the day
over southernmost portions of the forecast area. Mostly SN is
expected, with some RA mixing in for MHT/PSM/CON late
afternoon/early evening. This will likely bring a period of
MVFR/IFR ceilings as well, and reduced vis. LLWS is possible
late tonight as low level winds shift and increase, while
surface winds remain south to SW. Conditions improve to VFR by
Saturday and continues into Saturday night.

Long Term...We will begin the period with widespread VFR
conditions under high pressure. Precip will move in Sun night
with areas of IFR developing...especially where snow is
predominate ptype. Mixing will be most likely across southern NH
perhaps into the PWM area. Conditions will return to VFR by Mon
night.

&&

.MARINE...
Short Term...SCA winds slacken by this afternoon as rain and
snow onset through Fri night. NW flow and cooling temps again
bring chance for freezing spray late Fri night into Saturday.

Long Term...Gusty offshore winds will continue thru most of Sat
with SCA conditions expected outside of the bays. There will be
a brief break Sun but southerly winds are forecast to increase
Sun night. While southerly winds typically are not as strong as
modeled...they do look sufficiently strong for at least SCA
conditions. Wind direction will gradually shift to west
southwest as colder air moves back over the waters and SCA
conditions will continue thru early next week.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ150-
     152-154.
     Small Craft Advisory until noon EST today for ANZ151-153.

&&

$$
NEAR/SHORT TERM...Cannon
LONG TERM...Tubbs