Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 221325 AFDGYX Area Forecast Discussion National Weather Service Gray ME 925 AM EDT Thu Jun 22 2017 .SYNOPSIS... High pressure will build over the area through today. Tropical moisture from the remnants of Cindy and an approaching frontal system will result in showers and thunderstorms Friday into Friday Night. A series of surface troughs or weak cold fronts will cross the area this weekend into early next week bringing us the chance of showers from time to time. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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925 AM...No significant forecast changes. Some updates to T/Td/Sky based on current obs, and held back cloud cover for a few hours late today early this evening. Overall, should be a nice dry day with highs in the 70s to around 80, plenty of sun, and low RH. 616 AM...Minor ESTF update to ingest the current mesonet into near term grids. Prev disc... At 06z...a weak frontal boundary extended from the Gulf of Maine through southern New England and the mid Atlantic region. a weak 1017 millibar high was centered over Northwest Pennsylvania. For today...a sunny start as the weak surface high slides eastward. We`ll see mid and high clouds begin spreading into the area during the afternoon as the stalled boundary to our south and west begins to return as a warm front. high temperatures today should be in the upper 70s and lower 80s...but a bit cooler across the mountains as well as along the mid coast of Maine.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Tonight clouds will thicken as the warm front advances into the region...with showers and scattered thunderstorms spreading north and east across the area during the predawn hours of Friday. Lows will be in the 50s across the mountains with lower and mid 60s elsewhere. On Friday...steadier shower and thunderstorm activity will taper as the warm front lifts to our north by afternoon as Low pressure tracks eastward to the north of Lake Ontario and into southern Quebec. We`ll see showers and thunderstorms redevelop in the warm sector and with a passing shortwave impulse during the afternoon. There could be some brief torrential downpours as some of the tropical moisture from the remnants of Cindy gets entrained into the storm system. It`ll be a warm and humid day with dewpoints in the 60s and lower 70s...with high temperatures in the lower and mid 80s over the southern half of New Hampshire and adjacent southwest Maine and in the 70s for the remainder. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Large scale troughing across much of the northern two-thirds of the CONUS will continue to impact northern New England through the weekend and the upcoming week. By early next week the trough will have sharpened and pushed the Bermuda high farther south as it carves out a deeper trajectory...dipping into the southeastern states. The trough axis stays to our west through at least Tuesday at which point GEFS and ECMWF ensemble spaghetti plots become a huge jumble indicating disagreement among the various members. Thus there is low confidence in the forecast beyond the beginning of next week. On Friday night showers and thunderstorms will be ongoing with a warm front to our north and a cold front poised to cross the region. The timing of this looks late for much strong convection, but general thunderstorms with heavy rain and nuisance flooding will be possible with plenty of tropical moisture streaming from Cindy to work with. West winds should arrive Saturday morning bringing drier air into the area. However, the remnants of Cindy will be near NJ at this point. This additional moisture and lift will strengthen the baroclinic zone in the vicinity, possibly allowing for additional rainfall. A cold front sags south from Canada Sunday and lingers near the international border, triggering more showers for the mountains and foothills. High pressure will strengthen over the center of the CONUS with lower pressure areas ringing the center. This will keep the Gulf of Maine open for south to southeast winds to pump moisture into New England resulting in more scattered showers and possibly a few rumbles of thunder through midweek. Temperatures will generally be around normal with readings in the upper 60s to lower 80s for highs and overnight lows in the upper 40s and 50s. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... Short Term /through Friday/...VFR. Areas of MVFR developing tonight in shra/-tsra and continuing Friday. Long Term...Low ceilings will persist Saturday morning in showers and fog. Conditions will improve to VFR Saturday outside of the mountains with HIE and LEB possibly seeing some periods of MVFR in lingering showers. On Sunday a cold front will approach from the north bringing more MVFR conditions to HIE, LEB and possibly AUG. On Monday showers will encompass all of the terminals with some heavier showers and thunderstorms bringing visibilities and ceilings down to IFR at times. Conditions improve Monday night. && .MARINE... Short Term /through Friday/...Winds/seas will stay below SCA levels through tonight. On Friday we`ll see strengthening southerly flow ahead of a cold front with seas and wind gusts outside the bays approaching SCAs during the afternoon and evening. Long Term...Waves may remain in the 5-6 ft range for the easternmost outer waters through Saturday. Otherwise conditions are expected to remain below SCA criteria in the long term marine forecast. && .TIDES/COASTAL FLOODING... Hi astronomical high tides are expected Friday night and again Saturday night. Tides may exceed minor flood levels and some inundation is possible. If any surge or waves develop in addition to this then impacts my increase. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Cempa SHORT TERM... LONG TERM... AVIATION... MARINE... TIDES/COASTAL FLOODING... is the U.S. government's official web portal to all federal, state and local government web resources and services.