196
FXUS61 KGYX 080019
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
719 PM EST Fri Feb 7 2025

.SYNOPSIS...
High pressure building in tonight through Saturday. Another low
pressure system brings accumulating snow to the region Saturday
night through Sunday. High pressure returns for the starts of
the work week next week. Another low pressure system is then
possible midweek next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
715 PM Update... Went ahead and let the gale warning expire and
replaced it with a small craft advisory. Skies across southern
NH and coastal ME are primarily clear at this hour with more in
the way of clouds over the foothills and points north. Radar
mosaic does show some weak returns under these clouds, which
could be indicative of some flurries. Other than tweaking winds
and temperature trends through this evening, the fcst remains
on track.

Previously...
A well mixed layer will continue tonight under a brisk west to
northwesterly flow. This will allow for single numbers for
overnight lows in the north and lower to mid teens in the south.
The upslope flow will allow for enhanced cloudiness and some
snow showers across the northern higher terrain for at least the
first half of the night and have gone above most guidance pops
for that region.

&&

.SHORT TERM /SATURDAY NIGHT/...
On Saturday, a narrow ridge of high pressure will crest over
the Northeast. Clouds will begin to increase from the west as
the surface ridge moves off the coast and low pressure enters
the Ohio River Valley.

Most available guidance remain in relatively good agreement
bringing a surface low into the Mid Atlantic region before a
secondary area of low pressure develops off the New Jersey
coastline. The track thereafter makes for a challenging forecast
as the system shifts almost due east by late Saturday night. The
flow is mainly westerly aloft with only the hint of an H8 low
developing as the system shifts further off the coast.
Nevertheless, the available QPF combined with modestly high
liquid to snow ratios may allow for a band of 6"+ snowfall
across southern portions of the region. The latest HREF solution
appears to be reasonable for this snowfall forecast. Have
therefore decided to extend the watches one row of counties to
the north and include York County in Maine. This necessitates
the expansion of the watch which is in very good agreement with
neighboring offices.

Temperatures in the teens and lowers 20s Saturday night along
with cold temperatures aloft will allow for mostly an all snow
event. Several inches of snow will accumulate by Sunday morning,
making for slick travel for any travelers over the weekend.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Key Message: Active weather pattern thru the extended and beyond.
Temps largely near normal but above normal chances for precip.

Impacts: Tue night/Wed snow is possible but may remain south of the
area. If it does snow it may impact the morning commute Wed. A
stronger storm is likely Thu/Fri with more snow and maybe a
mix.

Forecast Details: Focus was mainly on the two winter events within
the day 8 window.

Pattern remains in a -PNA state...with a trof over the western
CONUS. That will leave our region within the baroclinic zone
and in the path of numerous fast moving S/WV trofs.

The first of which arrives Tue night into Wed. Currently the
atmosphere will still be recovering from the weekend snow and the
favored storm track may be too far south. Ensemble guidance shows
this outcome with around half of the members having no QPF locally.
This is especially true with the GEFS and GEPS ensemble suites. I
had maintained the PoP at chance just above climatological normals
for this time of year.

A stronger S/WV trof will round the base of the trof and eject
towards New England Thu. This one looks stronger and more likely to
bring widespread QPF to the forecast area. There is a high pressure
well positioned ahead of the storm to allow for snow to
state...though the storm track may offer some additional threat of
mixing across southern zones if the primary low tracks far enough
west. NBM PoP did look too fast with this system...so I delayed
onset slightly and lowered PoP to account for that uncertainty.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Upslope cloudiness will allow for MVFR conditions
in the mountains at HIE tonight with scattered snow showers.
Otherwise, VFR conditions expected overnight into Saturday.
Ceilings lower Saturday night with snow entering the region with
developing IFR and LIFR conditions developing from southwest to
northeast.

Long Term...The extended with be oscillating between periods VFR and
IFR in snow. The best chances for IFR or lower conditions will be
Tue night into Wed across southern NH...followed by Thu or Fri
across the entire forecast area.

&&

.MARINE...
Short Term...Gale warning continue into this evening before the
gradient begins to diminish. Gales may need to be dropped to
SCAs across the outer waters and Penobscot Bay tonight.

Long Term...Marginal SCA conditions are possible Tue with the passage
of low pressure south of the coastal waters...but largely winds and
seas are expected to remain below SCA thresholds until late in the
week. The Thu/Fri storm system will bring a more widespread threat
of gusty winds and building seas.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Watch from Saturday evening through Sunday
     afternoon for MEZ018-023.
NH...Winter Storm Watch from Saturday evening through Sunday
     afternoon for NHZ007>015.
MARINE...Small Craft Advisory until 11 AM EST Saturday for ANZ150.
     Small Craft Advisory until 7 AM EST Saturday for ANZ151-152-
     154.

&&

$$

NEAR TERM...Tubbs
SHORT TERM...Cannon
LONG TERM...Legro