Area Forecast Discussion
Issued by NWS Portland, ME

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933 FXUS61 KGYX 281126 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 726 AM EDT SUN AUG 28 2016 .SYNOPSIS... High pressure will move east of the area today. A cold front will approach Maine and New Hampshire tonight and move off the coast monday morning. High pressure will build over the region Monday and move of the coast Tuesday. Another cold front will move through Wednesday afternoon. Cool high pressure will build in over the remainder of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Update...Minor changes to reflect latest observational trends. Mainly adjusted sky cover based on morning IR satellite imagery...and increased PoP across Nrn NH during the morning to capture showers moving across Nrn VT at this hour. Previous discussion...A warm front will continue lifting thru the region aloft this morning. Shower activity look to be tied to that mid level front...and so should remain N of the international border. Gradually as the cold front approaches...showers will start to move into Nrn zones around mid morning. To the S of the boundary warmer temps and increasing moisture will build some instability into the local area. The best heating and moisture transport will be to our W...where around 1000 J/kg is possible. Across parts of NH we will probably only be able to muster around 500 J/kg...but good enough for an isolated thunderstorm or two. Shear does increase later in the afternoon too...to around 30 kts. So a stronger storm is not out of the question...but again I think the best chances for storm organization will be to our W. SREF and NCAR ensembles favor NY state...and I tend to agree. But it would not take much heating and stronger moisture return to get that environment into far Wrn NH. For now I will have thunder in the forecast...but leave enhanced wording out. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... A SWly low level jet develops tonight and moves across the forecast area. This should sustain WAA showers for much of the night until the front passes. On the nose of the low level jet the layer may be just warm and moist enough to provide a bit of elevated CAPE for thunder. I will include isolated thunder wording thru the night until the column begins to dry out. The front really mixes down Mon...with drier air working into the region. Winds may gust to near 20 kts in the afternoon. Temps near the coast should be slightly warmer than today...with some compressional warming ahead of the front. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Models are in fair agreement for the long term. fairly benign weather for much of the up coming week. High pressure will build in Monday night and move off the coast Tuesday. Wednesday we will get briefly warm and humid ahead of a cold front that will move through late in the day or evening. Showers and possible thunder will occur ahead of this front. High pressure will build in Wednesday night and Thursday. Models are indicating that a fairly strong shortwave will move from north to south across the forecast area Friday resulting in a burst of showers and possibly an isolated thunderstorm. Have just mentioned a 30 pop for now in the mountains for Friday. However if the current trend continues I expect the pop to increase with showers making it to the coast during the day. High pressure will build in on Saturday. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... Short Term...Patchy valley fog will lead to local IFR or lower conditions thru the CT River Valley this morning. VFR conditions should prevail for most of today...until late when a cold front will approach from the W. Widely scattered SHRA or TSRA could lead to MVFR or lower conditions...especially across the CT River Valley. SHRA or an isolated TSRA will sweep across the forecast area with the front...with areas of MVFR and maybe local IFR in heavier convection. Coastal stratus may develop too...which would affect PSM...PWM...AUG...and RKD. Gusty Wly winds around 20 kts Mon will clear things back out to VFR...except at HIE where upslope clouds may keep some near MVFR CIGs. Long Term...Expect VFR Monday night through much of Wednesday. late on Wednesday mvfr in showers possible. VFR Thursday. && .MARINE... Short Term...SW flow will bring moisture back N over the waters thru today. That may allow for some coastal fog/stratus to form by tonight. Model forecasts are uncertain about if or when it forms...so confidence is not high enough to have in the forecast just yet. As front crosses the waters Mon...seas may build outside of the bays to near 5 ft. A SCA may be needed for some of the outer waters. Long Term...SCA is possible Wednesday ahead of the cold front as southwest winds increase and push seas to near 5 feet. SCA is also possible Friday on an increasing northwest wind. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Legro

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