056 FXUS61 KGYX 310150 AFDGYX Area Forecast Discussion National Weather Service Gray ME 950 PM EDT Fri May 30 2025 .SYNOPSIS... Showers will gradually diminish tonight with the loss of daytime heating. However fog and low clouds will begin moving in from the Gulf of Maine overnight ahead of a strong late spring storm. A widespread, soaking rainfall will move through the region during the first half of Saturday. Rain could be heavy at times, but overall it looks like a steady light to moderate rainfall. The storm will wind down to showers Saturday night and showers may linger into Monday before beginning to clear out. Temperatures will also be much cooler Sunday into Monday. After that we become warmer and drier as high pressure builds across the Northeast for much of next week. && .NEAR TERM /THROUGH SATURDAY/... 930 PM UPDATE...Forecast remains on track. Low stratus is starting to advect onshore, with recent observations at KRKD and Vinalhaven now showing cloud decks of only ~500ft. Low stratus is still expected to continue creeping onshore, with areas of fog arriving across the coastal plain shortly after. 6 PM UPDATE...Forecast remains on track. A few edits were made to cloud cover and temperatures to reflect most recent observations. Previously... Diurnal showers have popped up mainly across two parts of the forecast area. One in the mtns...where elevated heat source is the primary driver of convection. The second is over southeastern NH where a little convergence band has developed and is forcing showers northeast along it. Not seeing much evidence of ice in the cloud tops just yet...but I would not rule out a rumble of thunder from any of these. Otherwise most of tonight should be dry and mild for this time of year. There is a fog bank lurking off the tip of Cape Cod...and hi- res guidance brings it onshore around or just after midnight. This seems reasonable to me...so I have used the HRRR for timing of fog and low clouds in the forecast. && .SHORT TERM /SATURDAY NIGHT/... Most of the precip will arrive after sunrise Sat...so I will include that in this portion of the discussion. A well defined S/WV trof crossing the Appalachians today will lead to cyclogenesis early Sat along the Mid Atlantic coast and crossing southern New England. Model guidance is converging on a track that cuts across ME...so it looks increasingly like we will experience the WAA precip but largely miss out on the deformation banding. With the dry slot moving over much of the southeastern part of the forecast area I suspect that model QPF may be slightly high once WAA precip shuts down. So I lowered QPF after 18z Sat for those areas...and storm total precip is now just below 1 inch. In the mtns where southeast upsloping and more of the wrap around precip occurs totals remain 1 to 1.5 inches. Still do not anticipate any flood threat out of this event...but the risk if there was any is shifting west. Sat night will remain unsettled and showery. The focus will primarily be in the higher terrain...where northwesterly upslope helps to drive the lift. With clouds and showers around the temps should remain mild. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Overview... The upper level low associated with the Saturday system slowly exits through New England on Sunday. High pressure begins to build in on Monday. The high continues to build on Tuesday, along with a moderating trend. The highs moves offshore by Wednesday, with a building warm airmass and moisture for Wednesday and Thursday. A cold front then approaches late in the week from the west. Details... Sunday sees relatively drier conditions as the upper level low moves through New England. More breaks of sun allow temps to warm into the mid 60s south of the mountains, with 50s across the higher terrain. With the cold air aloft, pop up clouds and showers likely develop by the early afternoon after some morning sun and heating, especially across the higher terrain. These dissipate late in the day, with a drying trend Sunday night. High pressure builds in from the south on Monday, marking the start of a multi day warming trend for next week. With WSW flow, warmer temperatures likely reach the coast on Monday, before a shift to a sea breeze late in the day. Highs are generally expected to reach the 70s downwind of the mountains, with 60s across the higher terrain. Some clouds are possible through the first half of the day as the last of the trough exits, with more sun by late in the day. The warming trend continues through the week as the high builds, and then shifts offshore Wednesday, setting up a more synoptic southwesterly flow. Widespread 70s look likely for Tuesday, and widespread 80s for Wednesday and Thursday. With the high offshore, a stronger sea breeze would be expected along the coast each day after a quick morning warm up. Humidity also begins to increase by Thursday, with dew points in the 60s looking increasing likely. By late in the week, a cold front likely approaches from the west. The progression of this front is still quite uncertain, and still a week away. A strong ridge builds across the Northeast by late in the week, and is unlikely to break down too quickly with the approaching front. This leads to some spread amongst the models on just how quickly it will move, or if it even ends up arriving at all. Regardless of whether it arrives or not, chances for showers and storms increase late in the week in the moistening airmass, and warmer conditions are likely to continue until the front passes. The one other feature to watch by the end of the week and into the weekend would be high pressure building from the north with the potential for a back door cold front in the late week to weekend time frame. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Short Term...VFR conditions this evening will give way to an expanding marine stratus layer around midnight. Areas of IFR or lower are expected from PSM to all western ME terminals. Near the coast fog may become dense at times. Rain will move in near daybreak and may act to mix out the fog a bit. Low CIGs will remain until winds shift to a west of north direction. Despite that there may be lingering MVFR CIGs into Sat night. Long Term...Some MVFR conditions with showers are possible on Sunday, especially at HIE. Mainly VFR prevails early next week, but nighttime valley fog will be more likely mid to late in the week. Some marine fog will also be possible at RKD by Thursday. && .MARINE... Short Term...South winds will continue to turn onshore thru overnight. Areas of fog are expected to develop across all waters and fog may be dense at times. With low track now forecast more inland that will to a longer and stronger duration of onshore winds before shifting to southwest. I increased wind speeds Sat slightly to go along with building seas...so a period of SCA conditions is looking more likely Sat. Long Term...Marginal SCA conditions linger into Sunday with southwesterly flow behind the departing low, and lingering seas. High pressure then slowly builds across the waters early next week, and shifts offshore by midweek. SCA conditions will be possible in increasing southwesterly flow from Wednesday through the end of the week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM UPDATES...Palmer NEAR/SHORT TERM...Legro LONG TERM...Clair AVIATION/MARINE...Clair/Legro