Area Forecast Discussion
Issued by NWS Portland, ME

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820 FXUS61 KGYX 071349 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 849 AM EST Wed Dec 7 2016 .SYNOPSIS... A weak trough will move across the region today. This will spread light snow into southern areas of the area around the morning rush hour, but accumulations are expected to be very light. A slow moving upper level low pressure system will move through southern Canada Thursday and Friday, spreading some snow showers into the mountains. This will also drive an arctic cold front through the area later on Friday bringing much colder temperatures for the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Update...WAA is forecast to continue weakening over the area thru early afternoon. This is allowing snowfall to slowly taper off over Wrn ME. I do not expect accumulations to reach the 1 to 2 inches seen over parts of NH this morning...but could still result in some slick roads. Behind this initial lift we remain in cool...cyclonic flow so clouds and flurries should linger into the afternoon. Previous Discussion: A weak short wave trough in advance of a broad upper Great Lakes trough will move through the upper ridge axis exiting to the east today. As it does so, the trough will get dampened out but will still have enough lift to produce a band of light snow or snow showers to move across the area with snow totals of less than an inch accumulation expected. A very dry air mass is in place at this time so the light snow will only manage to reach NH and extreme southwest Maine for the morning commute. During the mid- late morning the snow should reach all other areas north and east. By later in the day the periods of light snow or flurries will come to end over southern areas and then places north and east by evening. There could be a mix or changeover to rain showers briefly over southern areas and along coastal areas before the precipitation ends in the afternoon as some boundary layer temps warm and approach 40 degrees.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... Tonight and Thursday very little in the way of any clearing expected as the broad upper trough over the Great Lakes moves eastward into New England. This cyclonic flow will keep clouds across the area. In the mountains scattered snow showers can be expected. Stayed close to blended model guidance for temps. Overnight cloud cover will keep temps from falling so lows will be in the 20s. Thursdays high temps should be in the 30s to near 40. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Not much change from the previous thinking on the long term as latest deterministic and ensemble model guidance looks largely unchanged as a whole. The bottom line remains below normal cold and the chance of a winter weather event Sunday night and Monday. Cold air will be ushered in Thursday night in the wake of a short wave trough and attendant cold front. Cold northwest flow then continues through Saturday night with upslope snow showers in the mountains through Friday. Both Friday night and Saturday night will likely feature widespread lows in the teens and single numbers. Saturday night should be the coldest night with SFC high pressure cresting overhead. Low temperatures may have to be adjusted downward a bit at the good radiators if thick cirrus associated with an approaching short wave trough doesn`t move in too early. The next chance of appreciable snowfall continues to be centered around Sunday night as a couple of short wave troughs traverse the region. The 00z deterministic runs haven`t changed too much from previous runs so therefore the general initial idea remains the snow event for most with possible mix far south...starting Sunday afternoon or night and lasting into Monday. There are a few short wave troughs that are involved here and still need to be better resolved moving forward - so forecasts may change a bit over the next few days. At this time will continue with a mostly snow forecast. Thereafter it looks possible that another cold shot arrives by midweek. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... Short Term...Mostly MVFR conditions expected today with light snow or flurries as the weak trough moves through the area. Tonight and Thursday generally VFR condition expected except in the mountains where scattered snow showers will persist. Long Term...Mainly VFR conditions expected Thursday night through Sunday. The exception will be in the mountains where lower conditions are expected Thursday night through Friday in snow showers. && .MARINE... Short Term...Winds and seas to remain below SCA criteria through Thursday. Long Term...Northwest winds to small craft advisory levels are expected Thursday night through Saturday night. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Legro is the U.S. government's official web portal to all federal, state and local government web resources and services.