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. --714FXUS61 KGYX 282246AFDGYXArea Forecast DiscussionNational Weather Service Gray ME646 PM EDT Tue May 28 2024.SYNOPSIS...A cold front exits to the southeast tonight with a few showerspossible. An upper level disturbance slowly crosses the regionWednesday and Thursday bringing partly sunny skies. Highpressure crosses the region this weekend and builds to the southearly next week. This will provide dry and warmer conditions.&&.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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646 PM...Minor update to reflect observational trends. Troughaxis moving east across Upstate NY will continue the chance forisolated showers across the north, mainly Coos County.Otherwise, drier air moving into the area will lead todiminishing shower chances after sunset.Previously...Surface cold front is currently pushing the CAPE rich airmass toour east with only one area of storms being triggered on thisboundary. This storm will quickly move off to the east intoPenobscot County. Instability showers with an upper level troughare also moving into NH but instability is mostly limited withmuch drier low level air. Expect the upper level shortwave tomove across the area by midnight allowing for the chance forinland showers through most of the night but will be isolated toscattered in coverage. Most areas will experience a pleasantand dry evening though.
-- End Changed Discussion --&&.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...Elongated 500mb trough axis will be over New England tomorrowbringing with it cooler temperatures as a Canadian airmasspushes into the region. This will bring a nice day tomorrow withhighs mostly in the low 70s with a relatively dry airmass inplace. It will be mostly sunny south of the mountains with alight northerly breeze. Clouds will be on the increase acrosssouthern areas late afternoon into the night as a weak vort maxpivots north ward in the mid-level flow across Southern NewEngland. A few showers could be possible by the overnight hoursacross southern areas of the CWA. Overall QPF amounts will belight.&&.LONG TERM /THURSDAY THROUGH TUESDAY/...High wave number pattern continues across the N Hemisphere at500 MB, but flow becomes a little less amplified, and thisshifts the trough and closed lows poleward, and also weaken thema bit. Although we start the period in a trough, this willshift E and weaken allowing for more zonal flow at 500 MB, andpossible 500 MB ridging early next week. To sum up, we arelooking at mainly dry period, with a gradual warming trend.Thu morning will see weak sfc low tracking ENE out of S NewEngland, through the downstream side of 500 MB trough. It lookslike a remnant of convection from the previous day, soconfidence is not high, but chance POPs in srn NH and along theME coast seem reasonable at this time, given that this featurehas been in this vicinity for several models runs. To the N,Thursday looks partly to mostly sunny and seasonable cool withhighs in the mid 60s, while in the S look for highs in the upper60s to low 70s. Thu night will be the last chilly night forawhile, as sfc high slowly builds in. Itll be mainly clear withlows around 40 in the mtns, coolest in the sheltered valleys,to the mid to upper 40s in the S.Friday through Monday look mainly dry, and generally sunny assfc high pressure gradually builds over the CWA, and mid levelflow turns SW allowing warmer air to move in. Highs on Friday ofthe mid 60s to low 70s, will increase some each day reaching tothe mid 70s N to low 80s S by Monday. Overnight lows willmostly be around 50 to start the weekend, but closer to the midto upper 50s by Monday. One possible complication maybe aweakening convective system moving in from the W Sunday morning,but still lots of uncertainty at this point.&&.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...Short Term...Any remaining IFR conditions due to the marinelayer on the mid-coast will push off to the east by the eveningas the surface cold pushes the marine layer out of the area. Afew showers are possible in the mountains and CT River Valleybut most areas will remain dry. The one area of thunderstormsover the Kennebec River valley will depart the area quickly thisafternoon. Expect VFR conditions tonight through tomorrow as fogisn`t expected to develop tonight. Quiet weather except for afew pop-up showers by late afternoon across Southern NH but notexpected to impact aviation operations.Long Term...Mainly VFR expected Thu through Mon. Could see somebrief MVFR in SHRA Thu morning at coastal terminals.&&.MARINE...Short Term...Small craft advisory conditions will end thisafternoon as seas drop below 5 feet. Flow becomes off shoretonight as winds switch to the NW behind the surface cold frontending foggy conditions over the waters. Seas will subsidetomorrow and continue to slowly subside tomorrow into Wednesdaynight.Long Term...High pressure settles over New England from Thunight into early next week, and winds/seas expected to remainbelow SCA levels during that time.&&.GYX WATCHES/WARNINGS/ADVISORIES...
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ME...None.NH...None.MARINE...None.
-- End Changed Discussion --&&$$NEAR TERM...Dumont/SchroeterSHORT TERM...DumontLONG TERM...Cempa