Area Forecast Discussion
Issued by NWS Portland, ME

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421
FXUS61 KGYX 192148
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
548 PM EDT Sat Aug 19 2017

.SYNOPSIS...
A cold front will sweep offshore early tonight. High pressure
follows this front overnight through Monday and will slide
offshore on Tuesday. A cold front will move in from the west
Tuesday night and will cross the region on Wednesday. High
pressure will build in behind the front Wednesday night through
Friday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Update...
Have updated the forecast per current observations and trends.
Plenty of Cu remain over northern areas where the terrain kick
will work with limited instability to produce widely scattered
showers and perhaps a stray thunderstorm overnight. This
relatively light precipitation will be associated with the
passage of an upper level trough during the overnight hours.

Elsewhere, some low level moisture from yesterdays heavy rain
will become trapped underneath a developing inversion overnight.
This will lead to patchy fog throughout much of the region.

Have made minor adjustments to temperature trends, dew points
and cloud over over the next few hours.

Prev Disc...
At 18z...a 1007 millibar low was off the downeast
coast with a trailing cold front through the Gulf of Maine. A
1001 millibar low was centered over northern Quebec with a
trailing cold front through the eastern Great Lakes. We`re
seeing gradual clearing today behind the departing disturbance
over the Gulf of Maine. However, heating and the approaching
cold front may trigger a brief shower/isolated thunderstorm
through early tonight mainly across the higher terrain.
Overnight...partly cloudy skies with patchy fog and valley
stratus developing in wake of cold front and shortwave impulse
sweeping offshore.

&&

.SHORT TERM /SUNDAY NIGHT/...
For Sunday...ridging takes hold although we`ll see a few upslope
clouds across the higher terrain. It`ll be a warm day with highs
ranging from the 70s across the mountains...to lower and mid 80s
elsewhere. Partly cloudy Sunday night with some patchy late
night fog and lows in the 50s to lower 60s. &&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Models remain in fairly good agreement today on extended forecast
for next week. High pressure will crest over the region early
Monday before shifting offshore south of New England. Return flow
will bring warmer and more humid air back into the northeast
through the day under mostly sunny skies. Highs on Monday will
generally range through the 80s.

Summer-like weather will continue Monday night and Tuesday.
Looking for partly cloudy skies Monday night with lows in the
lower to mid 60s. Tuesday will start off mostly sunny with high
clouds on the increase in the afternoon as a cold front
approaches from the west. Looking like a hot one with highs in the
80s to lower 90s. May see some convective activity reaching far
northwest zones by late in the day but expect a majority of the
forecast area  to see a dry day.

Cold front will push in from the west Tuesday night. Looking for
showers and Thunderstorms overnight some of which could be severe
with heavy rainfall. Moderate to strong shear will combine with
PWAT`s approaching 2 inches to produce possible damaging winds
and heavy rainfall. Although timing of the front not ideal...
strong dynamics associted with this shortwave should sustain
convection well into the evening and overnight. Looking for a very
warm and humid night with lows in the 60s to lower 70s.

Cold front will slow as it moves through the region early Wednesday
but  should finally move offshore by Wednesday afternoon. Highs on
Wednesday will range from the mid 70s north to the mid 80s south.

Skies will be mostly clear Wednesday night as high pressure begins
building in from the west. Should see much more comfortable
conditions as cooler and drier air shifts into the region on a
northwest flow.

High pressure will dominate the weather for the rest of the week
and into the weekend. Upper trough settling into the northeast will
result in A mix of sun and clouds during the days with mostly clear
and cool conditions at night. Highs Thursday through Saturday will
range through the 70s with lows overnight in the upper 40s to mid
50s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...


&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
Short term /through 12z Monday/...Lingering MVFR over mid coast
Maine will become VFR by early evening. Overnight...areas of
MVFR and lcl IFR will redevelop in stratus and fog. Bcmg VFR
throughout Sunday morning with lcl IFR psb btw 08 - 12z Mon in
valley stratus and fog.


Long Term...
VFR Monday through Tuesday. Areas of MVFR/IFR ceilings/vsby in
showers and thunderstorms Tuesday night. Becoming VFR for
Wednesday through Thursday.

&&

.MARINE...
Short Term /through Sunday Night/...SEas continue to diminish
and the small craft advisory for hazardous seas has been dropped.


Long Term...
SCA`s may be needed Tuesday into Wednesday.

&&

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

&&

$$
NEAR/SHORT TERM...Cannon



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