655
FXUS61 KGYX 111018
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
618 AM EDT Fri Apr 11 2025

.SYNOPSIS...
A cutoff low will stall south of New England today through the
weekend, bringing an extended period of cool and unsettled
weather conditions. The system then moves away by Monday with a
return to drier and warmer conditions early next week as high
pressure returns. A cold front approaches from the west Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
615 AM Update... Minor changes to reflect latest observational
trends. Light rain and snow persist across portions of the area
at this hour but webcams and road sensors indicate that there is
little to no accumulation across roadways. This precipitation
will persist for the next hour or two before ending later this
morning.

Previously...
Northeast radar mosaic early this Friday morning shows
precipitation streaming from southwest to northeast in
association with low pressure located to our southwest and a
trof of low pressure situated over the Northeast. ASOS and MPING
reports indicate that light rain and snow has begun across much
of southern NH with the general theme being that most locations
are starting as rain and then through wet bulbing they are
quickly transitioning to snow. DOT road temperature sensors
indicate that roads are mainly into the middle to upper 30s
across the region, which is helping to limit snow accumulations
to mainly non-paved surfaces. This can also be seen through area
webcams. Latest hi-res guidance and upstream observations do
indicate that a brief period of heavier snowfall rates is
possible within an hour or so either side of 12Z though and this
could temporarily allow for some slushy roads.

Little in the way of precipitation is likely over much of
western ME this morning as forcing for ascent is expected to
quickly dissipate once it exits NH but despite this some light
snow remains possible with a coating in some spots. It will
otherwise remain a cloudy and chilly morning with lows bottoming
out into the 20s and 30s.

Light snow mixed with rain will end by mid-morning across the
area as the vort max exits to our north and some slightly drier
air moves into the mid-levels. Skies will remain mainly cloudy
through the day though as we remain under broad trofing and
easterly flow will limit high temperatures to mainly the 40s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
Tonight will feature cool and damp conditions but there will
likely not be much in the way of precipitation until after
midnight across extreme southern NH and then towards dawn
elsewhere. Low temperatures will be into the 20s and 30s.

A more organized wave of moisture from cutoff low pressure to
our south looks to arrive on Saturday morning. Latest forecast
guidance indicates a growing potential that a band of strong
h7/h85 frontogenesis along with strong omega within a saturated
dendritic growth zone will lift northward across the area
between roughly 7am to 2pm on Saturday. Should this occur then a
period of moderate to heavy snowfall rates would be likely with
localized rates between 1-2"/hr not out of the question. This
potential can now be seen through the WPC Snowband Probability
Tracker (SPT) using both the latest HREF and HRRR. Some guidance
is more bullish than others, however, with both the placement
and magnitude of this potential front end thump of snow with
some indicating the forcing will weaken as it lifts north.

Nevertheless, based on this new guidance did increase QPF and
snow amounts some with totals now approaching advisory criteria
in portions of southwestern NH. It is possible these amounts
will need to be raised further in other locations but given the
wobbling of guidance the last few days, did not want to make
complete wholesale changes yet. Winter Weather Advisories may
later be needed for portions of the area depending on later
forecasts.

Following this initial shot of strong forcing, by the afternoon
forcing looks to decrease with some drier air moving into the
-12C to -18C layer. This will decrease precipitation intensity
 and likely allow for a changeover to rain or at least a
 rain/snow mix in areas outside of the mountains. High
 temperatures will be mainly into the middle to upper 30s.

Rain and snow will end from west to east on Saturday night with
low temperatures primarily into the 30s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Long Term Update... Little change from the previous forecast.

Previously...
Another area of low pressure passes off the coast that may
continue precipitation chances for coastal areas Sunday. Monday
appears dry with brief high pressure, before another low across
central Quebec brings a cold front through Tuesday. The region
will continue to experience effects of this broad upper low
through to Wednesday.

Timing and spatial differences continue into Sunday as a low
further off the coast follows northward. Deterioration of the
initial low south of New England will expand the influence of
cyclonic flow, resulting in a period of greater moisture content
off the coast. How far inland this influences either
precipitation or just cloud cover differs. Kept a chance of rain
in the forecast for the coast and parts of the interior through
Sunday given this uncertainty. Will need to keep an eye on if
dry continental air is more readily advected south across the
forecast area to keep this moisture off the coast.

Greater consensus is given Monday into Monday evening as high
pressure quickly passes through the area. This could be the
bright(er) spot of the forthcoming week before a cold front
arrives and the region experiences unsettled weather under an
upper low through mid to late week.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
Short Term...MVFR to IFR CIGs due to -SNRA/low ceilings will
persist through mid- day before mostly improving back to VFR.
The exceptions could be at KLEB and KHIE where MVFR restrictions
could linger through much of the day. Winds will be out of the
east at 5-10 kts. Light and variable winds will prevail tonight
along with mainly VFR conditions. A period of moderate SN and
low ceilings is then possible from 12Z-18Z on Saturday with IFR
to LIFR restrictions possible. SN will then transition to mainly
RA later in the day but low ceilings will cause lingering
restrictions with northeast flow prevailing. No LLWS is
currently anticipated.

Long Term...Precipitation shrinks to the coast Sunday, with MVFR
ceilings continuing and possible IFR near or just offshore.
Conditions trend to VFR Monday under high pressure.

&&

.MARINE...
Short Term...High pressure exits to the northeast of the waters
through tonight with low pressure arriving on Saturday. This
will result in increased northeasterly winds and building
seas... leading to SCA conditions.

Long Term...Wave heights may remain 5 to 6 ft until Monday when
high pressure moves overhead. A cold front will approach the
waters Tuesday morning.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from noon Saturday to 8 PM EDT Sunday for
     ANZ150-152-154.

&&

$$

NEAR TERM...Tubbs
SHORT TERM...Tubbs
LONG TERM...Cornwell