National Weather Service (2024)

Area Forecast Discussion
Issued by NWS Portland, ME

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-- Discussion containing changed information from previous version are highlighted. --780FXUS61 KGYX 281306AFDGYXArea Forecast DiscussionNational Weather Service Gray ME906 AM EDT Tue May 28 2024.SYNOPSIS...A cold front will pass overhead today, crossing the coastalwaters tonight. An upper level trough slowly crosses the regionWednesday through Friday with more scattered showers and nearseasonable temperatures. High pressure passes south of the areathis weekend.&&.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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9OOam Update...Quick update this morning to handle a few showersacross the northern mountains as a pre-frontal line ofinstability moves through the region. Besides that fog willslowly burn off this morning, with it holding on the longestacross the Kennebec River Valley and Mid-coast. Only a few areasare remaining around 1/4 mile visibility, so decided to let thedense fog advisory expire. Showers and isolated thunderstorm arestill expected this afternoon, especially across the mountains.620am Update...Cloud heights dipped lower over the course of theearly morning hours, resulting in dense fog. This is mostprevalent along the ME coast and NH seacoast at this hour.Issued a Dense Fog Adv through 9am as these likely will lingerthrough morning rush hour after the holiday weekend. HREFprobabilities keep low vis over the coastal waters through muchof the mid and late morning hours. Thus while fog should liftreadily this morning across the interior, areas along theimmediate coast may still deal with patchy fog through midafternoon.Previous Discussion...Warmer today as low pressure passing north of the St. LawrenceRiver pulls a cold front through the region today. It`s alongthis that the chance for reinvigorated showers and perhaps athunderstorm develop late this morning and afternoon. Lots ofdry air will have moved into the mid and upper levels, sodevelopment of these showers will really depend on the liftingfunction of the front.Instability will need to build on the heels of receding cloudsthis morning, and hires guidance does depict and axis of CAPEtracking through the mountains and most of interior westernMaine. HREF soundings have an appreciable amount of DCAPE, andshowers or storms with higher echo tops should prove to havesome gusty winds with them. However, lack of coverage andmoisture downplays confidence in mentioning this as asignificant hazard.
-- End Changed Discussion --&&.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...Center of the trough will move overhead this evening andovernight, resulting in showers approaching from the west. Lowconfidence in these making an impact overnight. Another mildnight will be on tap for coastal and interior locations.Wednesday will bring the chance of additional shower developmentand perhaps a rumble of thunder as upper trough slowlyapproaches the area, with broad low pressure centered near JamesBay. Temperatures run a few degrees cooler than Tuesday as lowlevels finally switch NW with cooler conditions.&&.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...Overview: A mid-level trough and cutoff low pressure systemwill remain near Northern New England through Friday, which willresult in continued chances for scattered showers at timesalong with near average temperatures. Drier conditions are thenlikely by next weekend.Impacts: Little to no major weather related impacts are expected.Forecast Details: Scattered showers will remain possiblethrough Wednesday night with cool overnight temperatures intothe lower to middle 40s. The cold front will move over the Gulfof Maine on Thursday but a weak sfc low may develop along it.This will result in scattered showers through much of the day,especially south of the mountains. High temperatures will remaincool with lower 60s across the north and upper 60s to near 70degrees south.Showers will likely become more isolated in nature by Thursday nightas the front and weak wave of low pressure slides north and east ofthe area. Low temperatures will be mostly into the 40s. Highpressure will build to our west on Friday but latest guidanceindicates an inverted trough may develop, which would result in cooland showery conditions once again. This portion of the forecast isof lower confidence though as heights will be rising through theday. Therefore, capped PoPs to slight chance at this time. Hightemperatures will be into the 60s to lower 70s. Drier andslightly warmer conditions are then likely next weekend as an h5ridge axis moves overhead and sfc high pressure slideseastward.&&.AVIATION /13Z TUESDAY THROUGH SATURDAY/...Short Term...IFR/LIFR conditions early this morning willimprove to MVFR/VFR towards the afternoon. There still may be abank of low stratus or fog that sits just off the ME coastthrough the evening, but otherwise restrictions improve duringthe day. SHRA develop this afternoon across the interior, butshould be isolated. TS will be most likely north or around AUGfor a short window this afternoon. MVFR ceilings return tonorthwestern NH this evening. SHRA possible Wednesday, withmostly VFR ceilings.Long Term...Mainly VFR conditions are expected outside of anyscattered -SHRA and potential nighttime FG. Winds will beprimarily out of the west at or below 20 kts.&&.MARINE...Short Term...The waters transition from a wind/wave SCAconditions to just waves after mid morning. Waves up to 5ft willcontinue to be possible this afternoon. A cold front overheadwill slowly begin to push east tonight with broad low pressureremaining to the NW through midweek.Long Term...Seas up to around 5 ft are possible across the outerwaters Wednesday night through part of Thursday but otherwisewesterly winds and seas will likely remain below thresholdshazardous to small crafts.&&.GYX WATCHES/WARNINGS/ADVISORIES...
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ME...None.NH...None.MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ150>152-154.
-- End Changed Discussion --&&$$SYNOPSIS...NEAR TERM...DumontSHORT TERM...CornwellLONG TERM...TubbsAVIATION...MARINE...