Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
210 FXUS61 KGYX 311801 AFDGYX Area Forecast Discussion National Weather Service Gray ME 201 PM EDT Sun Aug 31 2025 .SYNOPSIS... High pressure will bring mostly dry days into the 70s and cool nights. High pressure shifts offshore mid week as a trough swings through the Great Lakes. This trough will send a frontal system towards New England late in the week for the next chance at some wetting rains. && .NEAR TERM /THROUGH TONIGHT/... Fairy weather afternoon continues into this evening. Some congested cumulus are likely over the Moosehead Lake region and parts of the Upper Kennebec Valley and a sprinkle is possible...but showers should remain northeast of the forecast area. Tonight high pressure builds in and good conditions for radiational cooling will be in place. I opted to lower NBM min temp guidance several degrees. Overall lows will look similar to last night...with some upper 30s possible north of the White Mtns. Valley fog is also expected once again...but coverage will be a little less than normal thanks to all the dry weather. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... Not much change to the weather Mon and Mon night. As high pressure drifts east a bit the sea breezes will push farther inland than today. But with temps already cooler and waters as warm as they typically get there will not be much change across the sea breeze front besides a stronger breeze. More radiational cooling and valley fog is expected Mon night. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A weak and broad 500mb trough over the eastern United States will allow for cooler temperatures to remain in the forecast for Tuesday and through second half of this week. Mostly clear and dry weather is expected on Tuesday. Temperatures will generally be in the upper 70s, sometimes approaching 80F across I95 and I93 corridors south of the mountains. An upper-level low to the north, combined with some instability generated from daytime heating may allow for a few diurnally driven convective showers north of the White Mountains on Wednesday. However, these storms should be pretty isolated and most places up there may only see a few hundredths of an inch of rain, if anything. A similar setup is likely for Thursday, though drier air from high pressure will wiggle onshore and allow for dry air to penetrate farther inland. This additional dry air should prevent showers from developing in the mountains on Thursday. By the end of the week, a more robust 500mb trough develops and tries to swing to the south but is likely remain to the west of New England. A cold front and a northward moving shortwave over the Atlantic Ocean may allow for some measurable rainfall during the day on Friday and potentially continuing into Saturday as well. At this time, confidence is highest to see measurable rainfall across western NH and the interior, though the ECMWF 10th percentile QPF shows at least a good quarter of an inch of rain is expected most places Friday and Saturday. Weather over next weekend looks to remain cool and somewhat unsettled. Notable drought relief is not expected despite a potentially wet end of the week. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... Short Term...VFR conditions this evening and Mon. Tonight and Mon night valley fog is expected. I have opted for near persistence for LEB and HIE fog tonight. More fog is expected Mon night as well. I anticipate that the coverage of fog will not be as widespread thanks to the ongoing drought conditions...so I do have restrictions in the TAFs in other valley locations like CON/MHT/AUG. Long Term...Fog Tuesday morning may briefly lower restrictions, otherwise VFR is expected through the rest of the day Tuesday through the end of the day Thursday. Thursday night, showers and storms move in, lowering restrictions through Friday and possibly Saturday as well.&& .MARINE... Short Term...Winds and seas are expected to remain below SCA thresholds. Sea breeze will stick near the coast today but should develop sooner and push farther inland on Mon. Long Term...Light and variable winds are expected over the waters on Tuesday and will continue through Wednesday morning. Winds pick up a bit and shift to southwesterlies at 5-10kts Wednesday morning, gradually increasing to 9-15kts by the end of the day. Southerly/southwesterly winds more or less continue at 8-17kts on Thursday and Friday. Seas of about 2-4ft are expected through the entire period. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Legro SHORT TERM...Legro LONG TERM...Palmer