700
FXUS61 KGYX 190305
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
1105 PM EDT Tue Mar 18 2025

.SYNOPSIS...
Warmth remains in place as high pressure lingers through
Wednesday. Another storm will send a front through the region
late this week. Some snow accumulation looks possible for parts
of the higher elevations at least and maybe into the valleys. A
dry but breezy weekend will give way to another storm system
early next week. This storm will also bring a threat for
accumulating snow so we cannot quite closer the book on winter.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

11:05pm Update... Some minor adjustments were made to bring
down temps for some of the cooler radiational cooling spots
overnight based on trends so far this evening. Otherwise, the
forecast remains on track as high clouds move offshore.

7:00pm Update... No notable changes with this update as the
forecast remains on track. High clouds continue to gradually
shift eastward through the evening, allowing for a mainly clear
and dry. This sets up favorable rational cooling conditions,
with most locations likely dipping into the 20s tonight, with
low 30s more likely across parts of the coast and southeast New
Hampshire.

Previous...

Satellite imagery and observations currently show clouds
gradually exiting the region. Skies will clear this evening as
high pressure moves into the area. Calm winds and clear skies
tonight should lead to radiational cooling with low temperatures
bottoming out in the 20s across the region.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Tomorrow morning will start chilly, though temperatures should
rebound quickly as diurnal heating builds through the day. Mid-level
vorticity stemming from an approaching low will allow for clouds to
move into the area tomorrow afternoon. Low stratus builds up over
the Gulf of Maine tomorrow afternoon. In addition, a wind shift to
southerlies will allow for this low-level stratus deck to build into
most locations south and east of the mountains tomorrow tonight.
Drizzle and dense fog are likely with this cloud deck as it hovers
over the area. The low clouds will keep lows warmer tomorrow night,
with low temperatures primarily in the upper 30s and lower 40s.
Gloomy and dreary conditions tomorrow night will continue into early
Thursday morning.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

Evening Update:
Model consensus remains poor on the timing of the transition to
snow with the system on Friday, and where the placement of this
snow would be. There is also still some question as to whether
the system will actually deepen as quickly as some guidance is
suggesting and be dynamic enough to flip rain to snow. So this
update continued to hedge more on the conservative side,
keeping the best chance for snow up across the higher terrain.
Afterwards another system looks likely early next week, bringing
another chance for both rain and snow.


Full Discussion:

Key Message: It remains too early to put winter to bed and the
extended remains unsettled with at least a threat for interior
snowfall.

Impacts: Aside from the threat of early spring snowfall...any
trends towards warmer and wetter...i.e. less snow...will enhance
the ice jam threat across the northern half of the forecast area
where river ice lingers.

Forecast Details: At the outset of the extended a front will be
approaching the Northeast. Sustained southerly flow ahead of the
system will likely lead to widespread fog and stratus ahead of
the precip into the early parts of Thu. Guidance continues to
hint at an occlusion forming and secondary low pressure trying
to develop along the triple point. This would help to shut off
warm advection and keep the system cooler as a whole. DESI
cluster analysis shows that members featuring a more robust S/WV
trof are more likely to develop this way and result in more
snowfall across western zones and higher elevations. The
forecast bears watching though as the mean snowfall amounts are
higher than the median...meaning a few larger solutions may be
influencing the average. Indeed examining individual members
shows more of a bi-modal distribution...with most members having
light accumulations but a handful 6 or more inches. For now I
will favor the lighter amounts...but especially tomorrow
sampling of the S/WV trof should give some indications of which
way to adjust the forecast.

A secondary S/WV trof over the weekend will bring a fresh shot
of cooler air and a chance for mtn showers. But the real
attention is on the next storm early in the week. Guidance has
another low pressure wrapping up a little closer to the forecast
area this time. There are also hints at secondary development of
low pressure near the coast...but also strong WAA ahead of the
storm. Depending on diurnal timing or location of the leading
high pressure there may be enough cold air around for another
threat of snow. Cluster analysis of this event shows similar
means across all clusters...indicating to this forecaster that
there are several different ways to produce snow out of this
one.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Short Term...
VFR prevails through Wednesday afternoon. Clouds increase
during the afternoon, with mostly scattered mid-level clouds
forecast to move across the region. Restrictions down to IFR are
expected tomorrow night as a low- level stratus deck moves into
the area. IFR will spread to most areas south of the mountains,
with areas north of the mountains staying mostly VFR through
the night. Restrictions will continue through Thursday morning.

Long Term...A period of extended unsettled weather is expected
in the long term. A front and precip will move into the area
Thu. Onshore winds will likely lead to areas of IFR or lower
conditions in fog and low stratus. As winds turn westerly Fri
into Sat conditions will return to VFR outside of the mtns.
Another system early next week will result in similar flight
restrictions...but may also have a threat for a little more snow
than rain as well.

&&

.MARINE...
Short Term...
Northerly winds of 10-20kts expected with 3-7ft seas. Winds
and seas should gradually diminish through the evening and overnight
hours. By tomorrow morning, winds shift to northeasterlies at 7-
13kts with 3-5ft seas expected. During the afternoon, low-level
stratus is expected to develop and substantially skew visibility.
Winds also shift to southeasterlies. By Thursday morning, seas
increase to 4-6 feet and southeasterly winds at 6-15kts.

Long Term...SCA conditions linger into early Thu...especially as
seas take a little longer to fall below 5 ft. It is possible
that as winds shift to a more southerly direction that seas
remain at or above 5 ft into the weekend. Then a storm system
will drive a cold front or occlusion thru the forecast area and
gusty westerly winds will develop on the backside. A brief gust
to around gale force is possible outside of the bays...with
SCAs likely for all waters Sat.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT Wednesday for ANZ150-152-
     154.

&&

$$


NEAR TERM...Clair
SHORT TERM...Palmer
LONG TERM...Clair/Legro
AVIATION...Legro/Palmer
MARINE...Legro/Palmer