Area Forecast Discussion
Issued by NWS Portland, ME

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015 FXUS61 KGYX 250429 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1229 AM EDT Tue Oct 25 2016 .SYNOPSIS... Low pressure meandering over the maritimes will provide a brisk westerly flow over the region through Tuesday, with some upslope snow accumulations expected in the mountains. High pressure will gradually 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 with some wintry precipitation in the mountains and rain elsewhere. More rain is possible later in the weekend. && .NEAR TERM /UNTIL 6 AM THIS MORNING/...
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1225 AM...just a quick update to bring grids in better line with current obs, A few flurries/sprinkles making their way out of the upslope and working into the interior coastal plain. This will continue for a few more hours but should wind down before daybreak. Previous Update...It is a pretty classic upslope snow shower look to the radar this evening. With Froude numbers above 1...and model forecasts to stay that way thru morning...I have added some flurries to areas S of the mtns. I do not expect enough snow to see any accumulations in those areas...but enough to see the first flakes for many tonight. N of the mtns...the forecast remains unchanged with snow showers continuing thru morning. I have upped the PoP at the higher elevations...with high chance to likely PoP for valley locales. Previous discussion...At 18z...a 990 millibar low was centered vicinity of the Gaspe Peninsula. A brisk westerly flow continued around this low across northern New England. GOES visible imagery showed broken to overcast clouds in the cool cyclonic flow around the associated upper low with a bit more sunshine across southeast New Hampshire into adjacent southwest coastal Maine. Temperatures ranged from 40s in the mountains to lower and mid 50s over the southern half of New Hampshire and southwest coastal Maine. NWS Doppler radar mosaic was indicating scattered light return across the mountains where there are widely scattered sprinkles or flurries occurring largely dependent on boundary layer temperatures and elevation. For tonight...the vertically stacked disturbance to our north will meander a bit further south while several weak impulses rotate around it. clouds will spread further south and east overnight with some upslope rain and snow showers across the higher terrain. The terrain above 1500 feet vicinity of the international border could see an inch or two of wet snow overnight with little if any expected at lower elevations. Lows will be in the 30s.
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&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 AM WEDNESDAY/... Tuesday will get breezy again, although a little less so than today. While upslope rain and snow showers will diminish in coverage, they will continue throughout the day, with some light accumulation still possible in the higher terrain. Some sunshine can be expected in the downslope on the coastal plain with highs a couple degrees cooler than today on average. Becoming Partly to mostly clear along the coastal plain Tuesday night...while clouds linger elsewhere in the persistent cool cyclonic flow. A few lingering upslope Snow showers are possible across the higher terrain. Lows Tuesday night will range from the upper 20s to lower 30s. With a bit less wind tomorrow night...we may finally be able to officially end the growing season in coastal York and Rockingham counties. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Cool cyclonic flow will remain over the region on Wednesday providing for brisk and chilly weather. More clouds than sun is expected, especially across northern zones. A cold night is expected Wednesday night as high pressure moves over the region. Northeastern zones may hold onto some clouds throughout the night and would allow temps to not go as low there. However, southern and western zones should see clearing skies and lows in the 20s over a pretty widespread area. A short wave trough and associated sfc low pressure and warm front will approach early on Thursday. Forcing for ascent will increase from SW to NE across NH during the day Thursday, and will then push across the entire CWA thursday night. The antecedent air mass will likely be cold enough across portions of central and northern NH as well as the western ME mountains to allow for accumulating snow later Thursday afternoon and night. Depending on how cold the column is and how much ascent develops to allow for significant cooling through melting and also evaporation, some lower elevations across SW/W NH may also see some snowflakes and perhaps a light coating of snow. The rest of the region should see rain due to warming boundary layer temperatures. There`s an outside chance that a couple of zones in NH and potentially the western ME mountains need an advisory for Thu night for snowfall. Thereafter, the column may warm enough to allow to a transition to all rain most everywhere. The rain could be heavy at times, especially Friday morning. Thereafter, a couple of weaker systems may affect the area late Saturday and Saturday night, with another possibly bringing more rain later Sunday and Sunday night. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Short Term /through Tuesday night/...VFR. Lcl MVFR psb tonight and Tue in mtn -shsn. NW sfc wind with gusts up to 25 kt through 22z Today before diminishing. Long Term...MVFR /IFR Ceilings developing Thursday Afternoon from west to east, possibly holding off until nighttime on the coastal plain and western ME mountains. IFR/LIFR ceilings/vsby Thursday night and Friday in rain (snow in the mountains). && .MARINE... Short Term /through Tuesday night/...Little change as the brisk circulation continues around the stalled low over eastern Canada. Small Craft conditions will continue tonight into Tuesday night outside the bays. Long Term...Small craft conditions likely Thursday night and Friday, with the possibility of low-end gales during that period also. && .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...None. NH...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ150- 152-154.
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&& $$ SYNOPSIS... NEAR TERM...Cempa SHORT TERM... LONG TERM... AVIATION... MARINE... is the U.S. government's official web portal to all federal, state and local government web resources and services.