Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 201951 AFDGYX Area Forecast Discussion National Weather Service Gray ME 351 PM EDT Sun May 20 2018 .SYNOPSIS...
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High pressure will build in from the west tonight and will pass out to sea south of New England Monday. Weak low pressure will pass south of New England on Tuesday. A cold front will drop south through the region Wednesday. Weak low pressure tracks along the international border late Thursday into Friday. A frontal system tracks into the area for the holiday weekend bringing widespread showers.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Cold front crossing the CWA, and other than a few sprinkles in srn NH thru about 4 PM, precip should be done. Will see a brief surge of W winds into early evening, with gusts to around 20 mph or so. Will still see a fair amount of clouds thru sunset, but certainly partly sunny in many spots, with rapid clearing expected after sunset. Winds will diminish over the first part of the evening, and should become light, which should set up a good rad cooling night, with lows dropping into the upper 30s in the sheltered mountain valleys, and into 40s to low 50s elsewhere.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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High pressure builds in from the west Monday and crosses the region Monday night. This will allow for unlimited sun, and mild conditions. Highs will be in the 70s, but may be a little cooler in the mountains. Will get close to meteorological Red Flag conditions on Monday, and Fire Wx Watch has been issued. See Fire WS discussion below for more. Weak SW flow on the boundary lyr should allow for slightly warmer temps than Sunday night, but some of the usual spots will decouple, so lows will generally run from around 40 in the north to the low 50s in the south. Cirrus may start to move in late, but the first part of the night should be mainly clear.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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The deterministic model solutions are now in decent agreement on the long wave pattern through the upcoming holiday weekend. We begin the period with a weak shortwave impulse racing eastward from the Great Lakes on Tuesday. Meanwhile...shortwave energy will ride over the top of a building western Canadian ridge and quickly carve out another upper trough across the Great Lakes and New England for the second half of the new work week. This trough shears out by the start of the holiday weekend with ridging in the interim for Saturday. By Sunday...models show troughing across the eastern half of the CONUS with various degrees of phasing between northern and southern stream energy. At this juncture...it looks like a dry start to the upcoming holiday weekend...then increasingly unsettled for the second half of the long weekend. In the dailies...a shortwave impulse and weak surface reflection will cross the area late Tuesday/early Wednesday with clouds and scattered showers. Another weak moisture starved boundary drops south across the area late Wednesday. High pressure briefly follows for Thursday. Another weak moisture starved boundary drops south across the area Thursday night/early Friday. High pressure and drier air briefly follows late Friday into Saturday. A slow- moving frontal system then moves eastward into the forecast area for the remainder of the holiday weekend...with clouds and showers gradually increasing in coverage.
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&& .AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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Short Term...Mainly VFR tonight thru Monday night. Some vly fog expected at KLEB/KHIE toward daybreak Monday. Long Term... Tue - Wed...Sct MVFR in -shra. Fri...Sct MVFR in -shra.
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&& .MARINE...
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Short Term...Will leave the SCAs up for now as seas still coming around 5 ft, but will likely see conds drop below SCA criteria in the next few hours. Otherwise, expecting sub-SCA Conds into Monday night. Long Term... Tue PM - Wed AM...SCA`s are psb...especially outside the bays. Thu PM - Fri AM...SCA`s are psb...especially outside the bays.
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&& .FIRE WEATHER...
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RH will fall to 25-30 percent Monday afternoon, with winds gusting to 20 mph, maybe as high as 25 mph in the north. This will just meet meteorological red flags conditions. After consulting with state forest rangers, thinking is that given the wind and full sun expected tomorrow, as well as temps in the 70s, this will dry things out quickly, so Fire Wx watch has been issued for the entire CWA for Monday aft into early eve.
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&& .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...Fire Weather Watch from Monday afternoon through Monday evening for MEZ007>009-012>014-018>028. NH...Fire Weather Watch from Monday afternoon through Monday evening for NHZ001>015. MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ150- 152-154.
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&& $$ NEAR TERM...Cempa SHORT TERM...Cempa LONG TERM...Schwibs

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