839
FXUS61 KGYX 072023
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
423 PM EDT Mon Apr 7 2025

.SYNOPSIS...
A weak area of low pressure passes across northern bringing
rain and snow showers to the south, and a steadier snow to the
north on Tuesday, where several inches of accumulation is
possible. Cooler but drier conditions will then return for the
middle of the week before more unsettled weather returns towards
the weekend.

&&

.NEAR TERM /TONIGHT/...
After a mostly dry day outside of far southern NH, damp weather
returns tonight into Tuesday. Not a large change in thinking,
but three or four main focal points over the next 36 hours.

For tonight, moisture depth remains variable as winds pivot
onshore this afternoon through the night. This will surely
supply moisture at the surface and low levels, but is it enough
for light precip outside of drizzle or fog? General trend for
the forecast is showery rain/snow in the south this evening,
transitioning to areas of drizzle around midnight and pre-dawn
hours for points east/south of the foothills. Surface temps will
play a role if some of this drizzle falls and clings on
elevated surfaces. This is mainly a concern getting into the
interior and foothills were overnight temps near 30 or the upper
20s. It will be hard to get slick surfaces elsewhere given the
warmer antecedent surfaces.

Moisture profiles do begin to saturate into the mid/upper
levels during the pre-dawn hours. This should result in very
light snow mixed with rain showers that will struggle to
accumulate. A more impactful feature approaches western NH
Tuesday morning.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Compact low pressure will quickly make its way out of the
eastern Great Lakes overnight, with its associated cold front
nearing western NH around 8am. Hires models have been fairly
consistent bringing a line of snow showers through along this
sharp forcing. With it expanding east into the forecast area
through the early afternoon, some parts of the line may approach
snow squall criteria with quick reductions in visibility due to
falling snow and gusty winds. Stronger winds appear more likely
behind the line of showers however, hence the downplay in
intensity.

This feature continues east into low level onshore flow. The
increase in convergence will cause more widespread snow to
develop inland from the coast. Rates increase, but should be
hard to accumulate before mid to late evening. Here, HREF
members have been attempting to develop a deformation zone and
perhaps a banding feature into parts of Somerset County. To
emphasize uncertainty in placement, the HRRR takes a narrow
band through Franklin County, while other guidance is nearly on
the border with Somerset/Piscataquis Counties. Considering the
recent westward trend, increased QPF and some snow ratios into
Somerset to at least account for this. This brings enough snow
to warrant a short Winter Weather Advisory Tuesday afternoon
into evening. Model profiles confirm a robust crosshair
signature of omega and the snow growth zone that increases
confidence in elevated snow rates mid afternoon. The single zone
Advisory is a good start, and can expand if needed should the
above trend continue. Into April, quick and low QPF events can
be hampered by the antecedent warm surface temps, thus expansion
was also weighed against this.

Touched on early Tues winds above, but gust factor looks to
increase come the late afternoon and evening. NW winds increase,
perhaps up to 30 or 35 mph, mainly across southern and central
NH. This then transitions to the ridges and higher summits of
the mountains overnight.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
The long term continues to feature the breakdown of the N
Atlantic block, which shifts E to Europe. We start off in a cold
trough trough Wed, but that eventually shifts N without the
blocking in place, and allows Atlantic ridging to build in from
the SE, which is also helped by 500 MB closed low deepening to
our SW. This will allow a gradual warming trend on Thu/Fri. The
latest 12Z Euro also shows the ridge keeping precip out of the
CWA until late Friday the GFS does not/. The models have had a
range of solns as to how this closed low develops and moves over
the last several days, so there remains a lot of uncertainty,
although there has been the best consistency centering precip
around Fri night and Sat.

As for Wed, it should be a mainly sunny day, a little breezy
and cool, with highs mid 30s N to mid 40s S. Wed night should be
mainly clear with calm winds, and some rad cooling can be
expected. Lows range from 15-20 in the mtns to the low to mid
20s in the S, probably making it the coldest night in the
forecast range. Thursday looks mostly OK, as winds shift SSW,
although there will be increasing clouds in the afternoon. Highs
range from the low to mid 40s N to the low 50s S. Thu night
looks mostly dry too, but wind will begin to shift onshore, and
clouds will overspread the area, as well, so mins will mostly be
in the 30s. Despite my chance POPS, Im leaning toward limited
showers on Friday, but, with onshore flow through most of the
day it will be cloudy, and highs will generally be in the 40s,
as the marine lyr settles in.

As mentioned, models have shown some run-to-run consistency for
precip Fri night into Saturday, and this where there are some
likely POPS. Its warm enough, that only it will be rain. The
only exception at times, may be the highest elevations. Even
this, just based on the pattern seems low confidence, and by the
time we get to Sunday confidence is even lower.


&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
Short Term...MVFR/IFR ceilings advance northward this evening.
This will be accompanied by light snow and drizzle at times
through the night. This could cause reduced visibility. Can`t
rule out pockets of freezing drizzle at some interior terminals
from LCI/IZG/LEW. After daybreak Tuesday, line of snow showers
will move through east to west bringing about a WNW wind shift.
Snow increases in intensity across central ME and mountain
terminals through the afternoon and evening. Winds will also
increase up to 30 kts across southern NH terminals Tuesday
afternoon/evening.

Long Term...VFR is expected Wed- Thu at least. Probably sometime
Thu night as the flow shifts onshore, will begin to see IFR or
lower first at the coastal sites, and later further inland,
sometime on Friday. KLEB/KHIE, may not see any restrictions
through Friday as they will be downsloping in the onshore flow.
Friday night and Sat expect restrictions everywhere in rain and
low cigs.

&&

.MARINE...
Short Term...Onshore winds continue this evening with inland low
pressure nearing the waters late Tuesday morning into the
afternoon. This low will bring a sharp cold front over the
waters, bringing a abrupt west wind shift and gusts up to Gale
force through the evening and overnight.

Long Term...SCA conds will likely be continuing into Wed
morning, but should subside during the afternoon. Beyond that,
expecting winds and seas below SCA conditions until Saturday.


&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 2 PM Tuesday to 2 AM EDT
     Wednesday for MEZ009.
NH...None.
MARINE...Gale Warning from 4 PM Tuesday to 2 AM EDT Wednesday for
     ANZ150-152-154.
     Small Craft Advisory from 4 PM Tuesday to 2 AM EDT Wednesday
     for ANZ151-153.

&&

$$

NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Cempa