Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 260227 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1027 PM EDT Tue Oct 25 2016 .SYNOPSIS... Low pressure will linger in the Maritimes through Wednesday. A narrow ridge of high pressure will build in from the west Wednesday afternoon through Wednesday night. Low pressure approaches from the west Wednesday night and will move east through southern New England Thursday night and northeast through the Gulf of Maine on Friday. High pressure will build in from the west Friday night and low pressure will approach from the west on Saturday possibly providing unsettled weather Sunday. && .NEAR TERM /TONIGHT/...
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1030PM UPDATE... Have made only minor changes to overnight low temperatures based on the latest observations. A clearing sky over southwest New Hampshire has allowed more cooling there, but winds continue to keep the low levels of the atmosphere fairly well mixed. Locations like Keene which are particularly well protected by surrounding terrain could well go calm and radiate very well leading to much colder readings, but overall temperatures will bottom out in the upper 20s to low 30s. 7PM UPDATE... Have updated the forecast mainly to make minor adjustments to precipitation chances and overnight temperatures. Although conditions are dry and clearing especially over southern New Hampshire, wind speeds overnight are expected to remain just strong enough to prevent good radiational cooling. This will limit overnight lows somewhat though temperatures in the upper 20s to low 30s are expected areawide. Expect the snow showers still visible on radar to wind down over the next several hours. ORIGINAL DISCUSSION... Moist cyclonic flow associated with stacked low pressure over northern Maine and the Maritimes will continue to bring cool, cloudy weather to a good portion of the region tonight. Upslope snow showers in the mountains should continue tonight, but become more intermittent later this evening. Another spoke of vorticity and associated weak forcing for ascent rotating around the larger parent low may bring some snow showers to eastern zones late tonight into Wednesday morning with no accumulation expected. Winds will diminish this evening. The growing season has therefore no frost/freeze products will be issued until spring.
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&& .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... Cyclonic flow remains on Wednesday as low pressure very gradually departs. The result will likely be another gusty and cool day along with scattered snow showers in the north. High pressure builds in Wednesday night allowing for decent radiational cooling, especially in the south and west which should bring temperatures down into the 20s for many locales. && .LONG TERM /THURSDAY THROUGH TUESDAY/... The ridge of high pressure will move rapidly east of the area Thursday as low pressure approaches from the west. Models are in good agreement with a low over Ohio Valley early Thursday morning moving northeast over Lakes Erie and Ontario as it weakens...with a secondary low developing and intensifying Thursday night and Friday in the Gulf of Maine. This will lead to a cold rain across much of the area Thursday afternoon through Friday. The precipitation should gradually spread northeastward from southwest New Hampshire during the day Thursday and become heavy Thursday night into Friday. The precipitation may start as a little wet snow well away from the coast. Across the higher elevations of the mountains, several inches of snow are possible before a changeover to rain. In lower elevations of the mountains, surface temperatures will be critical to any snow and may depend on the amount of warming that occurs during the day Thursday before the precipitation arrives. The low will depart slowly Saturday as a very weak ridge of high pressure crosses the area. Warm advection on the back side of the ridge will bring more clouds into the region late Saturday with the threat of rain for Saturday night through Monday morning as another area of low pressure moves east. High pressure will move into the area for early next week. In terms of precipitation, models are currently showing about an inch in most areas for the Thursday through Friday with more possible for Saturday night through Monday morning. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Short Term...Mainly VFR through Wed night, with the exception of KHIE, which will see some restrictions to MVFR in times in SHSN into this evening. NW winds will gust in the 20-25 kt range early this evening, but winds diminish tonight. Gusts around 20 kt likely Wednesday daytime. Long Term...MVFR to IFR conditions will develop Thursday and continue through Friday in rain (or snow in the higher elevations) and areas of fog. VFR conditions Friday night into Saturday will give way to MVFR to IFR conditions Saturday night and Sunday. && .MARINE... Short Term...SCA conditions for the bays into early this evening for gusts around 25 kt. The SCA on the ocean waters will go until late tonight. Winds will generally be lighter Wed and Wed night. Long Term...SCAs will likely be needed late Thursday through Saturday morning. SCA`s are possible again Sunday through early next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 5 AM EDT Wednesday for ANZ150-152- 154. && $$ NEAR TERM UPDATE...Kimble SHORT TERM...Ekster LONG TERM...Jensenius is the U.S. government's official web portal to all federal, state and local government web resources and services.