890
FXUS61 KGYX 182257
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
657 PM EDT Wed Sep 18 2024

.SYNOPSIS...
High pressure lingers for one more day, but does begin to break
down tonight. Moisture over the southeastern states builds
north behind this high with a slight chance for showers over
southern New Hampshire by Thursday. There may be a better chance
for showers Thursday night into Friday as low pressure develops
south of New England. High pressure builds in from the north
this weekend with more seasonable temperatures and dry weather
expected.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
650 PM Update...Little change to the going forecast. The
question that remains is how much fog will fill in on the coast
this evening. So far webcams on the coast show very little fog
at this time. Will continue to monitor. Otherwise, pretty quiet
weather as per the recent usual.

Previously...

Current satellite imagery shows a low pressure system bringing
some cloudier conditions into southern New Hampshire and
coastal Maine. A fog bank over the Gulf of Maine is currently
moving towards the Midcoast. Recent runs of the HRRR suggest
this fog will push into the coast after sunset and then push
inland past the I-95 corridor overnight. Areas of fog over along
the coastal plain will linger into morning commute tomorrow
with some localized dense fog possible. Radiational cooling
inland is also expected to bring some fog into the Connecticut
River Valley as well.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Areas of fog will persist along the coast through around 9 AM
before dissipating. A low tracking east south of Cape Cod will
try to bring moisture into southern NH and coastal areas. A few
isolated showers from this low may make it into portions of the
NH seacoast, York County and in Penobscot Bay. Northeasterly
flow at low-levels will help usher in cooler temperatures as
well, so tomorrow should feel noticeably cooler than today.

Tomorrow night, we near the astronomical high tide for the month.
Northeasterly flow over the Gulf of Maine might bring some
splashover and building surf could lead to beach erosion to the
NH/ME coastline south of Portland. Patchy coastal fog lingers
tomorrow evening and builds back up by Friday morning.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
12Z operational models and ensemble solutions continue to suggest
a relatively disorganized area of low pressure will remain
southeast of Nantucket Island as we begin the extended portion
of the forecast. During the period Friday through midday
Saturday, moisture will be attempting to reach southern portion
of the forecast area as moisture from off the coastline collides
with drier air over the interior. A northern and western
adjustment to the QPF has occurred since yesterday. This is more
consistent with the latest operational Canadian and European
runs but less in par with its ensemble solutions. In any case,
have raised pops across portion of the region, but still on the
low side of guidance. Despite the cloud cover, temperatures will
likely top out over 70 degrees in most locations.

Models also remain in relatively good agreement that this system
will begin to exit out to sea late Saturday allowing Canadian
High pressure over the Maritimes to retrograde back into our
region. This will allow for drying with any leftover showers
beginning to dry up by Saturday evening.

The Canadian High will allow for dry and seasonable conditions
Sunday and Monday across the Northeast. Temperatures will be
near normal for this time of the year.

The next chance for significant precipitation will hold off
until Tuesday and Wednesday of next week. A complex frontal
system will enter the region from the west accompanied by a
vigorous upper level trough that will track over the Great
Lakes. Temperatures will be seasonably cool for this time of the
year.

Coastal Flooding...The onshore winds forecast for the coast on
Friday will coincide with very high astronomical tides. This
may lead to minor coastal flooding near the times of high tide
during the early morning hours Friday, but moreso and more
likely during the Friday afternoon high tide.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Short Term...
Generally VFR expected through the remainder of the day. A fog bank
moves into the coast this evening, and will bring lower CIGS and
visibility to RKD, PWM and PSM. Confidence is highest over the
Midcoast and Penobscot Bay. Marine fog should expand overnight,
reaching AUG by early tomorrow morning. Valley fog along the CT
River Valley will bring LIFR conditions at LEB and HIE. Fog
should mix out by 10am tomorrow. Conditions improve to VFR
during the day Thursday. Low pressure spreads low clouds into
southern and coastal areas Thursday night that could bring
restrictions.

Long Term...VFR likely prevails during the day time late
Saturday and Sunday with MVFR conditions possible in scattered
showers Friday into Saturday. Night time valley fog will bring
the potential for IFR/LIFR most nights at KLEB and KHIE. Onshore
flow and increasing clouds from a system passing south of New
England will also bring the potential for cigs around MVFR
thresholds Thursday night and possibly into Friday.

&&

.MARINE...
Short Term...
Light and variable winds this afternoon with 2-4ft seas expected
this evening. A low will slowly move well offshore from the Gulf of
Maine and could bring some unsettled weather to the open waters
tomorrow. The low will also shift winds northeasterly with
sustained 15-20kts and gusts around 25 kts Thursday night. Seas
will also increase to 3-5 feet Thursday night with SCAs likely
needed late Thursday night into Friday morning.

Long Term...Low pressure passing south of the Gulf of
Maine will bring seas building to 5 ft by Friday with continued
NE flow with gusts around 25 kts, reaching SCA criteria. Seas
remain elevated around 5 feet into the weekend with NE winds
subsiding from their peak on Friday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$

SYNOPSIS...
NEAR TERM...Ekster/Palmer/Schroeter
SHORT TERM...Palmer/Schroeter
LONG TERM...Cannon
AVIATION...
MARINE...