Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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329 FXUS61 KGYX 181350 AFDGYX Area Forecast Discussion National Weather Service Gray ME 950 AM EDT Thu Jul 18 2024 .SYNOPSIS... A cold front will be moving off the coast this morning, bringing drier and not as hot conditions for the end of the week into the weekend. High pressure builds in from the west with mostly dry conditions forecast through the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 945 AM Update...It remains pretty muggy closer to the coast at this hour with dewpoints still hovering right around 70. However, the drier air is getting closer with dewpoints in the low/mid 60s in northern NH along with skies clear. Looking a bit farther upstream, dewpoints are in the mid 50s across northern VT. Little in the way of updates needed to the forecast, but I did keep a slight chance of showers in the forecast closer to the coast through this morning where the better moisture holds on longer, which is supported by the last couple runs of the HRRR. 640am Update...Refined PoPs to match current radar. Front is taking its time sliding east, but conditions will be improving through the day. A couple showers have strengthened towards the Midcoast, and could see a rumble of thunder out of them before they move northeast. Otherwise, still feels muggy this morning until NW breeze picks up this afternoon as the front is still analyzed back across VT/NH border. Previous Discussion... Showers wrap up along the coast early this morning as a cold front pushes off into the Atlantic. Overcast skies should trend mostly sunny through the day, with a breeze kicking in late morning and early afternoon. This will help reduce humidity today and through the weekend, with dewpoints returning to a more comfortable 50 to 60 range. Temperatures remain warm, with daytime highs along the coast and interior pushing into the mid to upper 80s. The only mention of rain chances comes towards central/western ME where a rogue shower may develop during peak heating. There will be plenty of dry air entering the mid levels, and think these would only produce a short sprinkle vs some recent downpours. These chances fall off in the evening. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Compared to recent warm, humid nights, tonight may almost feel like a different season. The combination of lower dew points advecting into the region plus temp values falling into the upper 50s and lower 60s will be welcome relief. Friday is set to be almost full sun as high pressure moves south of the region. Being in the NE quad will prove continued advection of drier continental airmass into northern New England. Temps will be similar to Thursday, mid 80s coast/interior, mid 70s to the north, perhaps a few degrees lower due to the aforementioned advection. Will likely see some introduction of a sea breeze in the afternoon along the coast, which brings a wind shift. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A weak cold front will bring a low chance of showers to portions of the region Saturday night into Sunday, but otherwise it looks pretty quiet for Friday night into the weekend. The highlight will be drier air in place, making it less humid out, and daytime temperatures won`t be as hot. Highs will be generally in the 80s south of the mountains, although a few southern areas could still reach 90 degrees on Saturday and Sunday. Nighttime will also offer relief with lows primarily in the 50s to lower 60s, and northern valleys may be even be able to dip into the upper 40s on a couple of nights if the skies remain clear and winds stay light. Valley fog will also be possible at night. Going into next week, there may be enough of an increase in moisture for a few showers to develop on Monday, but precip chances increase moreso toward Tuesday and Wednesday of next week as low pressure and a warm front lift toward New England. This is supported by the vast majority of ensemble members from the ECMWF and GFS, but due to this being toward the end of the forecast period and the inherit uncertainty, will not go as high as the NBM on PoPs yet. Temperatures look to remain near or slightly above normal from early to midweek. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term...A few terminals seeing IFR/MVFR early this morning in low ceilings, but a quick trend to VFR is expected today. Winds pick up late morning/early afternoon behind passing cold front, some gusts to 20 kt are possible this afternoon. VFR continues tonight and into Friday, with possible valley fog overnight. Long Term...High pressure and drier air will bring mostly VFR from Friday night through Monday, but there may be some valley fog during the night and early morning hours. A weak frontal boundary may bring a few showers late Saturday night into Sunday, but overall chances for these look low. Enough moisture may be sufficient enough for additional showers Monday afternoon. && .MARINE... Short Term...A cold front passes over the waters this morning, bringing a wind shift and perhaps some increases sustained winds through the afternoon. Waves remain generally 2 to 4 ft as high pressure begins to slide east towards the Mid Atlantic through the first half of the weekend. Long Term...SCA conditions are currently not expected from Friday night through the middle of next week. N/NW winds will be in place across the waters early Friday but will become more S/SW by the afternoon as the seabreeze develops and as high pressure becomes centered SE of the waters. Another weak frontal boundary could cross the waters late Saturday and into Sunday, resulting in another brief wind shift. High pressure looks to maintain control over the waters early next week before a low pressure potentially approaches toward the middle of next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Combs/Cornwell SHORT TERM...Cornwell LONG TERM...Combs