Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 190743 AFDGYX Area Forecast Discussion National Weather Service Gray ME 343 AM EDT Sun Mar 19 2017 .SYNOPSIS...
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Low pressure will develop southeast of Cape Cod today. This low pressure system will stay on the edge of the Gulf of Maine into tonight so any snow should be confined to Downeast. Warmer and dry weather is in store for Monday, with temperatures trying to get above 40 for the first time in a while in many places. Warmer air moves in for Tuesday with highs a little warmer than Monday. A cold front then moves through late Tuesday and temperatures fall off well below normal again for Wednesday and Thursday.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Baroclinic leaf developing off the Mid Atlantic coast this morning is marking cyclogenesis as s/wv trof exits the coast. Low pressure is forecast to develop and track NE towards the Canadian Maritimes. All of this is forecast to occur just outside the range of the majority of the forecast area. Lack of saturation is really going to limit snowfall on the NWrn fringes of this system...and so I have kept PoP mainly slight chance with some chance near likely on the far outer waters. Of note is the deep Ely flow across the Gulf of ME. Given temp differences greater than 10C...this is promoting cloud development and some convective echoes are evident on radar this morning. Given how dry it is across the area...I do not expect much of this to reach the ground...but I will maintain the flurry wording in the forecast. These ocean effect clouds and flurries will gradually dissipate into the early afternoon as flow becomes more Nly. Temps will be dependent on how much sun we get today. More sun and deeper mixing will result in some temps at least near normal. But thicker cloud cover could limit our mixing and keep us more in the mid 30s. Played things a little more on the warmer side...expecting the clouds to mainly be thinning thru the day.
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&& .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
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Starting tonight s/wv ridging moves into the region from the W. We will be on the edge of the surface ridge...so not completely ideal for radiational cooling...but I suspect a few sheltered valleys will get cold yet again. Despite shallow mixing Mon...warming temps aloft should result in fairly widespread temps near 40. This is notable since it has been roughly 10 days since that last occurred for most locations except for extreme Srn NH.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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The models remain in decent agreement on the longwave pattern into next weekend. We begin the period with a weakening ridge across the forecast area. The ridge quickly exits the coast as an upstream shortwave swings across the area on Tuesday driving a surface cold front across the area accompanied by a few snow showers and squalls over the higher terrain. A second shortwave impulse will dive southeast and help reinforce the colder air as it drives a second cold front southward across the area by early Wednesday. Upslope snow showers across the higher terrain late Tuesday and Wednesday will likely produce several inches of fresh accumulation...ironically as we mark the first full days of Spring here in northern New England. The upper trough will lift out during the day on Thursday...with models trending a bit quicker with its exit over the past day. Rising heights and surface high pressure building by to our south should allow for an upward trend in temperatures for Thursday although readings will still be a good ten degrees below average for the date. By Friday...a broad upper ridge will be centered across the southeast CONUS with warm frontal clouds spreading northward into the region along with an increasing chance for precipitation. A compromise of the various medium range solutions suggest the front will get hung up across the region for much of the weekend...resulting in a prolonged period of unsettled weather. In the dailies...a weakening ridge of high pressure will retreat offshore by early Tuesday. Tuesday should be the mildest day of the work week before a series of cold frontal passages reintroduce much colder air into the area for much of the second half of the work week. High pressure will build east and crest across the region on Thursday before retreating offshore by Friday. A warm front will move north into the region late Friday and Saturday then likely stall...resulting in unsettled weather for much of the upcoming weekend.
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&& .AVIATION /07Z SUNDAY THROUGH THURSDAY/...
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Short Term...Areas of MVFR CIGs are moving into coastal terminals this morning. Onshore flow is allowing some ocean effect clouds to move inland. This will affect mainly RKD...PWM...PSM...reaching at times as far W at CON and MHT. As flow becomes more Nly today this will dissipate and VFR conditions are expected into Mon. A few surface wind gusts near the coast to 25 kts are possible this afternoon. Long Term... Tue - Wed...Sct MVFR in mtn -shsn. NW sfc wind gusting to 25 kt.
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&& .MARINE...
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Short Term...Winds and seas will increase today as low pressure passes just outside the Gulf of ME. Gale force wind gusts are likely on the outer waters...with SCA conditions expected in the bays. Winds and seas diminish Mon as high pressure moves over the waters. Long Term... Tue PM - Thu AM...Small Crafts are likely, with winds approaching Gale at times outside the bays.
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&& .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...None. NH...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 8 AM EDT Monday for ANZ151-153. Gale Warning from 4 PM this afternoon to 8 AM EDT Monday for ANZ150-152-154.
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&& $$ NEAR TERM...Legro SHORT TERM...Legro LONG TERM...Schwibs AVIATION...Legro/Schwibs MARINE...Legro/Schwibs

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