Area Forecast Discussion
Issued by NWS Portland, ME

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078 FXUS61 KGYX 291953 AFDGYX Area Forecast Discussion National Weather Service Gray ME 353 PM EDT Sat Apr 29 2017 .SYNOPSIS... A cold front drops south through the region and pushes offshore tonight as high pressure builds in from the northwest. A warm front lifts into the region Sunday night triggering scattered showers. Low pressure slowly moving northeast out of the Great lakes will drive an occluded cold front through the region by early Tuesday with heavier showers and thunderstorms possible. Low pressure aloft will remain in control through the remainder of the week bringing periods of rain. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Temperatures have climbed to near record values across the region this afternoon with highs reaching into the low 80s in some locations. Those temperatures have already begun to drop as a cold front pushes through the region. West to northwesterly winds will continue to gust to 20 to 25mph this afternoon. Scattered clouds will dissipate as the front pushes into the region overnight. High pressure will briefly move into the region overnight into Sunday morning. Expect temperatures to drop to near or just below freezing in the northern mountains under clear skies as the valleys decouple. Have gone a touch lower in the north to account for this. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Sunday a warm front will lift northwards through the region touching off showers in the south around midday with expanding precipitation across the northern mountains into the overnight. This warm front is part of a much larger system currently centered over the central plains which will strengthen and move eastwards Sunday night into Monday. Most of this system will stay to our west so have kept PoP relatively low through the day on Sunday with higher values overnight as the system is able to progress eastward. Sundays high temperatures will be quite a bit cooler than today reflecting more of this afternoons cold frontal passage than tomorrow returning warmth and remaining in the upper 50s to low 60s. && .LONG TERM /MONDAY THROUGH SATURDAY/... A pool of cold air stationed over north central Canada will dip south towards northern New England this week, facilitating periods of precipitation and cooler weather. On Monday ridging aloft will shift east as the cutoff low over the southern Plains ejects northeast. This low will phase with northern stream energy and swing through the region by Wednesday morning. Another upper low will arrive for the weekend and linger for at least a couple days. At the surface, a warm front will be lifting into the area very early Monday. Showers will be concentrated along the higher terrain and along the boundary which will be stretched across northern NH and western Maine. Depending on how much of the region stays in the warm sector and how far east and north the warm front gets during the day, we could see 60s over much of NH, with 50s and upper 40s more likely as one moves east. An occluded front moves through late Monday bringing a line of showers and embedded thunderstorms through during the overnight period and into the early morning hours. Not expecting anything more than some rumbles of thunder at this point. PW values do jump up quickly along the front so there will be some heavier downpours. Expecting a large discrepancy in rainfall totals, with the coast getting the least and the higher terrain the most. Slightly drier and cooler air filters in Tuesday night, but cloud cover and gusty west winds will retard any significant cooling. The actual NW wind shift occurs late Wednesday with a fine line and possibly some shower activity for the mountains. Wednesday will be the "nice day" this week with temperatures warming into the lower 50s north to mid 60s along the coast with west winds. Another system will be poised to affect the region beginning Thursday night through Saturday, with a coastal low deepening rapidly over the Gulf of Maine. There are many questions regarding this system, but there should be enough moisture and lift for scattered showers with heavier rain a possibility. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... Short Term...VFR today through Sunday. Long Term...IFR conditions will be in progress by Monday morning as easterly flow provides low clouds and light rain or drizzle for all TAF sites. These conditions likely persist through Monday night. Showers and MVFR conditions may persist for HIE and LEB Tuesday into Wednesday morning with VFR elsewhere. Late Thursday showers will spread in from the SW so expect some MVFR conditions by evening. && .MARINE... Short Term...A few gusts to 25kts are possible this evening as the cold front moves over the waters, but generally expect the winds to be decreasing over evening so have opted not to issue any headlines. Long Term...SCA conditions likely Tuesday morning through Wednesday morning. && .FIRE WEATHER... Northwesterly flow in the wake of a cold front will push drier air into the region overnight. Weak high pressure will crest over the region on Sunday with mostly clear skies and moderate RH. A warm front will lift back northwards overnight Sunday into Monday bringing showers especially in the mountains. A generally wet pattern sets up for the next week as low pressure aloft spins pushing multiple rounds of showers through the region. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Curtis SHORT TERM...Curtis LONG TERM...Hanes is the U.S. government's official web portal to all federal, state and local government web resources and services.