Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 132346 AFDGYX Area Forecast Discussion National Weather Service Gray ME 646 PM EST Wed Dec 13 2017 .SYNOPSIS... Weak high pressure builds in tonight and tomorrow while a weak disturbance moves by to our south. After tonight our weather will be punctuated by fast moving systems moving across the region, with temperatures running below normal through the weekend. There will be a chance for some snow showers on Friday night, and another chance of snow showers or light snow Monday into Monday night. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Update... Temperatures dropping quickly this evening over northern areas. Significantly dropped the overnight mins for the mountains and foothills and portions of the interior valleys. More subtle lowering in the temperature forecast for the coastline where some breezes are continuing. Winds overall have diminished. Was able to cancel the wind advisories across the region. Prev Disc... Mountain snow showers will gradually lose their coverage and intensity through the evening and into the overnight. Cold air continues to pour in on west northwest flow. Good mixing this evening may allow for wind gusts to 40 MPH in southern New Hampshire and southwest Maine where the Wind Advisory remains in effect. Although this is just short of criteria, this will remain in effect due to the potential for tree damage after yesterday`s snow and ice. Winds diminish a little bit tonight, but the low levels will remain well mixed. Thus expect low temperatures to only be mostly in the teens, a few degrees below current levels. Single digits are likely in the mountains where the core of the cold air piles up. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Trough axis moves across the area tomorrow, with the best shortwave energy staying to our south where some light snow may fall. The chance of light snow in our area is fairly low and limited to far southern New Hampshire. Otherwise expect another breezy and cold day, with highs in the 20s. High pressure nudges in Thursday night with winds finally relaxing a bit. With dewpoints of 0 to 5 below, the floor for temperatures is pretty low. With decent radiational cooling conditions, temperatures will approach the zero degree mark and fall below it in sheltered valleys. Windier areas will have a tougher time cooling to these levels, but do expect widespread single digits. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... The higher amplitude +PNA pattern at 500 mb holds into the weekend, but then flattens somewhat early next week. Although troughing exits into the eastern CONUS, there are some farily fast moving waves tracking through the trough making for weaker and fast moving systems with little to no precip expected. Temps will be below normal although gradually warming to near normal by Sunday. After that, several waves carve out a trough over the northern Great Plains and we see some weak 500 mb ridging and SW flow which should push temps well into the 30s early next week, although this will be accompanied by another chance for precip Monday into Monday night. By the middle of next week, forecast confidence goes down as models still differing run to run and between the different models, but temps should drop back down again mid-late week. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Short Term...Mountain snow showers continue into the evening with MVFR ceilings and occasionally IFR visibility. This should diminish overnight with VFR conditions returning areawide by Thursday. Long Term... Mainly VFR through the weekend. Some tempo restrictions in -SHSN possible Fri night, especially at KHIE. .MARINE... Short Term...Gale force winds expected only for tonight. Have therefore discontinued the gales for Thursday. Long Term...SCA may be needed in NW flow behind a cold front Sat into Sat night. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Gale Warning until 6 AM EST Thursday for ANZ150>154. && $$ JC is the U.S. government's official web portal to all federal, state and local government web resources and services.