Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 181852 AFDGYX Area Forecast Discussion National Weather Service Gray ME 252 PM EDT Tue Jul 18 2017 .SYNOPSIS...
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Weak high pressure will build over the region tonight. A cold front will approach from the northwest on Wednesday and will drop south through the region Wednesday night. A shallow ridge of high pressure will build over the area on Thursday. Another weak cold front will drop south through the region on Friday followed by a secondary cold front Friday night. High pressure will build in from the northwest on Saturday and will crest over the region Saturday night.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Isolated showers and a few thunderstorms will gradually fade away through the remainder of the afternoon as drier air pushes in from the west. Expect inland areas to see just partly cloudy skies this evening before extensive valley fog develops in the usual locations. Moist onshore flow will continue and looking for ocean stratus to develop this evening in coastal and southern interior sections at some point during the evening... mainly from Portland eastward. Lows will range from the mid 50s to lower 60s north and mid to upper 60s south.
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&& .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
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Shallow ridge of high pressure will build over the region on Wednesday. Westerly flow will send temperatures soaring under mostly sunny skies. Morning fog will quickly burn off but ocean stratus may take much of the morning to clear especially in midcoast Maine. Highs will generally range through the 80s with lower to mid 90s in southern New Hampshire and extreme southwest Maine. Weak cold front will drop south through the region Wednesday night will little fanfare other than a few passing clouds. Lows will range from the upper 50s north to the upper 60s south.
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&& .LONG TERM /THURSDAY THROUGH TUESDAY/...
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Extended forecast continues with the general theme of trofiness trying to hang around the Northeast. This will promote a series of fast moving s/wv trofs to move thru the region thru the weekend. Thu looks to be a day in the wake of one wave...and wx should be more or less fair but warm. Again Fri another weak wave looks to pass thru the area...but confidence is low on timing. That will have a large impact on both thunderstorm chances and how hot it gets. With lingering moisture some heat index values in Srn NH may push 95 degrees. More showers/storms are possible Sat afternoon...along with continued heat and humidity for Srn zones. We will have to keep an eye on heat index values once again...to see if heat advisory criteria may be met. The strongest wave looks to be Sun/Mon...with deeper SW flow aloft and stronger forcing along the boundary. I kept likely PoP confined to this time period.
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&& .AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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Short Term...Areas of IFR/LIFR ceilings/vsby developing overnight...especially in valleys and coastal locations. Gradually becoming VFR Wednesday morning. VFR Wednesday night. Long Term...Generally VFR conditions to prevail thru the weekend. Some marine fog/stratus is possible ahead of approaching fronts...but confidence is low in occurrence. There will be a series of frontal boundaries that will cross the area thru Sun...with a threat for TEMPO MVFR conditions in SHRA/TSRA.
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&& .MARINE...
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Short Term...no flags. Long Term...Winds and seas are expected to remain below SCA thresholds.
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&& .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ Sinsabaugh/Legro

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