Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 241240 AFDGYX Area Forecast Discussion National Weather Service Gray ME 840 AM EDT Mon Oct 24 2016 .SYNOPSIS... Low pressure meandering over the maritimes will keep a strong west to northwest flow over the region through Tuesday, with upslope snow accumulations expected in the mountains. High pressure will build in from the northwest Wednesday and Wednesday night. Low pressure will approach from the west on Thursday and will cross the region Thursday night and Friday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 840 AM...for this ESTF update I made adjustments to near term grids that reflect both radar and satellite trends and the current mesonet. I expect cloud cover to expand south and east out of the higher terrain today with cool cyclonic flow and daytime heating. Prev Disc... 500 mb trough and associated sfc low are tracking across srn new England this morning. With dry air in place, and best dynamics moving south of the CWA, the precip will pass to our south. Cannot rule out a sprinkle moving along the NH/MA border thru about 12Z, but other than it will be dry. Will also see some clouds moving through with the 500mb trough, but these should clear out by mid- morning, too. Behind this wave winds will pick up again and another shot of colder will filter in this afternoon. The winds will not be as strong as Sunday but gusts of 25-30 mph will be possible, especially this afternoon. Upslope should get going again this afternoon in the mountains, but best chance for accums will be overnight. highs today will range from around 40 in the mountains, to around 50 on the coast and in southern NH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... NW flow continues tonight and another wave will move through the 500mb trough, so any clearing in the south will become partly to mostly cloudy by evening. This should also help enhance the upslope flow overnight and could see an inch or two of accums up to 2500 feet, and 2-4 inches above that. Winds will diminish, but should keep going at around 10-15 mph in many spots, which will deter rad cooling in all but the most sheltered areas. Overnight lows will range from around 30 in the north to the mid 30s in the south. Tuesday will get breezy again, although a little less so than Monday. While upslope SHSN will diminish somewhat in coverage and intensity, they will continue thru the day, with some accums still possible in the higher terrain. Some sun can be expected in the downslope on the coastal plain with highs a couple degrees cooler than Monday, mostly on the coastal plain, and temps will range from round to near 50. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Cyclonic flow will continue over the region Tuesday night and Wednesday as upper low slowly pulls off to the east. Looking for mostly cloudy skies Tuesday night with lows in the mid 20s to mid 30s. Clouds will hang tough in the mountains on Wednesday with downsloping winds producing a mix of sun and clouds to the south. Highs on Wednesday will range from the upper 30s to upper 40s. High pressure building by to the north will bring diminishing clouds Wednesday evening as upper low pulls away to the east. Good radiational cooling will allow temps to bottom out in the upper teens to mid 20s north and upper 20s to near 30 south. Shortwave approaching from the west on Thursday will bring the potential for a messy mix of wet snow...sleet and rain over higher terrain in interior sections of the forecast area as cold air dams up east of the mountains. Still some timing diffs between ECMWF and GFS but precip looking more likely to begin Thursday afternoon in southern New Hampshire and will spread northeast Thursday evening. Depending on the track of the surface low expect warmer air to gradually erode cold air over the region Thursday night as strong onshore flow sets up ahead of approaching low. Expect mixed precip in inland areas to gradually change to rain overnight. Rain will continue on Friday as low pressure crosses the region and will be tapering off in the afternoon as low pressure heads into the maritimes. Axis of heaviest precip will likely set up along the front range of the Whites in good upslope flow with models showing 1 to 2 inches in these areas. Models also indicating a fair amount of shadowing northwest of the mountains. Friday night will bring a break in the action as low pressure pulls away to the east. Models diverging quite a bit for the weekend so forecast confidence rather low for Saturday and Sunday. Will likely stay close to super blend pops for days 6 and 7. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... Short Term...VFR expected at all terminals into Tue. W-NW will gust from 20-25 kts today, especially in the afternoon. KHIE could see MVFR to IFR flight restrictions tonight, mainly in SHSN. Long Term...VFR Tuesday night and Wednesday with areas of MVFR ceilings in the mountains. VFR Wednesday night. MVFR /IFR Ceilings developing Thursday Afternoon. IFR/LIFR ceilings/vsby Thursday night and Friday. && .MARINE... Short Term...HAve dropped the gales for SCA outside of the bays, as W-NW winds will pick up a bit today and persist into Tue morning, at least. Long Term...SCA`s likely Tuesday night and Thursday Night. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 8 AM EDT Tuesday for ANZ150-152-154. && $$ ES is the U.S. government's official web portal to all federal, state and local government web resources and services.