Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 170235 AFDGYX Area Forecast Discussion National Weather Service Gray ME 935 PM EST Fri Feb 16 2018 .SYNOPSIS... High pressure will build into the region tonight and Saturday. Low pressure will move south and east of New England Saturday night and very early Sunday, bringing the potential for an accumulating snowfall...particularly to southern New Hampshire and the coast of Maine. As we move into next week...a warming trend is expected with temperatures moving well above seasonal norms...especially by Tuesday and Wednesday. There will be multiple chances for rain showers through next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 935 PM Update...Little change to the going forecast. Cold air advection will continue overnight with high pressure building in. Winds should noticeably diminish after midnight as the pressure gradient relaxes. 605 PM Update...Have adjusted the forecast slightly based on latest trends in PoP, sky, temperature, and wind. Front is through and winds are gusty. Gusts 25 to perhaps 30 mph will continue into the evening hours before diminishing. Otherwise, any precipitation is done except for areas of upslope snow showers in the Whites. Skies should rapidly clear downwind of the mountains over the next couple of hours. Previously... At 19z...a strong cold front was situated along the international border. While fog had lifted across the area GOES imagery continues to show extensive cloudiness across the region. A shortwave impulse noted over the eastern Great Lakes on water vapor imagery will race east this evening across northern New England and drive the cold front quickly offshore overnight. We`ll see a few rain and snow showers with the boundary and in post-frontal upslope flow this evening across the mountains...where snow showers could produce a quick inch or so of accumulation. skies will clear overnight in downslope northwest flow and under building surface high. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... A sunny start to the weekend as the surface high crests across the region Saturday morning before quickly retreating offshore. We`ll see some late days clouds over western sections of the forecast area in advance of the next disturbance...otherwise a dry...mostly sunny and seasonable day to start the weekend. For Saturday night...clouds overspread the remainder of the area from west to east in advance of northern and southern stream shortwave impulses over the Great Lakes and midwest. Progressive southern stream impulse will bring an associated surface low south and east of the 40N/70W benchmark early Sunday with surface trough extending northwest into coastal Maine. The QPF has come into better agreement on the 12z operational runs with the QPF axis showing a pronounced shift further south and east offshore. Potential snow amounts were lowered for this package with no winter headlines at this time. If current QPF trend continues...we may need a winter weather advisory for portion of southeast New Hampshire and along the coast of Maine for a general 3 to 5 inch snowfall Saturday night and early Sunday. && .LONG TERM /SUNDAY THROUGH FRIDAY/... *** The potential exists for temperatures to approach record breaking highs on Tuesday or Wednesday of next week *** 12Z model suite in good agreement that low pressure will intensify rapidly south of the Gulf of Maine Sunday morning, dropping 20 millibars in 24 hours. However, this southern track will allow for clearing Sunday after some very early morning snow Sunday morning as the main shield of snowfall remains out to sea. Any precipitation Sunday morning will mainly be confined to the Midcoast region. High pressure will build in from the Mid Atlantic region on Sunday into early Monday. This will push a warm front through the region late Monday as a broad area of mild southwesterly winds develop at the surface and aloft. The frontal passage may be associated with scattered showers. On Tuesday and much of Wednesday, the front will remain north of our region, allowing very warm H8 temperatures to advect into the region as high as +14C over southernmost portions of the forecast area. This will allow for well above normal temperatures Tuesday into Wednesday. Depending on mixing values, there is the potential for record breaking highs. The record high in Portland is 61 degrees on Tuesday (set back in 1994) and 59 degrees on Wednesday (set back in 1953). The warm front begins to drop south as a cold front late Wednesday and Wednesday night. High pressure will then build in from Canada with cooler, but still seasonably mild temperatures. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Short Term...VFR deteriorates to MVFR with areas of IFR and lcl LIFR vcnty of the coast in snow btw 01 and 05z Sun. Long Term...Conditions improving rapidly Sunday morning as low pressure races to the east. MVFR to IFR conditions will develop early to mid week next week as a front remains over northern New England. && .MARINE... Short Term...Winds increase to Gale tonight in strong cold air advection behind a cold front with strong SCA for Casco Bay. Winds and seas diminish Saturday under the cresting surface high. Winds and seas increase Saturday night with approaching ocean storm with SCA conditions likely outside the bays. Long Term...A gusty southwesterly flow will develop over the coastal waters early to mid week next week. Winds will be reaching SCA thresholds during this period. && .HYDROLOGY... Ice jams may be an issue next week. A large upper level ridge will build over the region early to mid next week. This will allow for well above normal temperatures with perhaps readings approaching record breaking highs. Showers will cross the region as well, associated with a frontal system. The precipitation and very warm temperatures may cause the ice jams to begin to move. Rapid fluctuations in waters levels are possible. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 5 AM EST Saturday for ANZ153. Gale Warning until 5 AM EST Saturday for ANZ150>152-154. && $$ NEAR TERM UPDATE...Ekster is the U.S. government's official web portal to all federal, state and local government web resources and services.