Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
350 FXUS61 KGYX 291900 AFDGYX Area Forecast Discussion National Weather Service Gray ME 300 PM EDT Fri Aug 29 2025 .SYNOPSIS... A slow moving front will continue to slide across New England this evening, with showers and thunderstorms gradually pushing east out over the Gulf of Maine. It will take a few days for the upper level system to cross the Northeast, so afternoon clouds and scattered showers are forecast over the mountains and foothills. Most locations will stay dry after today and dry weather continues through much of next week. Temperatures will mostly be seasonable with the potential for a few cooler than normal days sprinkled in. && .NEAR TERM /THROUGH TONIGHT/... Scattered showers and thunderstorms continue this afternoon along a cold front. Availability and amount of CAPE has been a limiting factor with most convection today. Entrainment has likely taken a toll on updrafts as storms cycle. Have noted a few gusts of 25 to 30 kt surrounding some storms, with one or two pea size hail reports from late morning convection. Rounds of showers and storms likely last into early evening, but will see a drying trend for western NH first. Main focal point of precip into the evening will be across southern ME, tapering off around midnight. Skies thin over SW NH overnight, and with slackening winds, valley locations may cool readily into the pre-dawn morning hours. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... Upper low to the west will present a cold pool aloft, splaying clouds across much of the forecast area Saturday. The immediate coast may be spared from overcast skies, but any further west and clouds should thicken through the day. Will also see some isolated to scattered showers develop, primarily over the mountains and foothills. Moisture layer is thin and not supported past 800mb, so expect showers that do develop to be light and widely scattered. The cool air will make itself known on the higher summits as wind chills fall below freezing Saturday and Saturday night. Actual temperature remains in the mid 30s to around 40 here, with the wind and damp conditions combining to quicken hypothermia onset if not prepared. Daytime showers end in the evening with skies clearing for locations south and east of the mountains. Expect a cooler night overall as the surface decouples and radiates well. Lows in the 40s can be expected as a result. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Key Message: Near to below normal temps continue thru the extended. Very little in the way of addition precip after today...so continued drying anticipated. Impacts: No significant weather impacts anticipated beyond maintaining/deepening drought conditions. A well timed high pressure could also bring the potential for frost in some northern valleys...but confidence in timing is low on that. Forecast Details: Lingering effects of the upper low continue to drive local weather Sun into Mon. Lower heights/colder temps aloft will promote diurnal cumulus development and scattered showers. This will be most likely over the mtns and higher terrain areas...but coverage remains a little uncertain. I could see terrain driving much of the forcing...but also a more robust cold pool allowing for wider spread shower activity. While the core of the cold anomalies is forecast to pass southwest of the forecast area...it will be seasonably cool. This will especially be true overnight...where surface high pressure and dry conditions will be favorable for radiational cooling. The timing of the surface high axis will dictate which nights are the coldest...but some northern valleys may potentially be frosty. In addition the White Mtns will see gusty winds and chilly temps. Hikers will see afternoon wind chills down into at least the 30s if not colder at times. The main story continues to be that beyond the weekend there is not much rain in the forecast again. Drought conditions may continue to expand. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Short Term...SHRA and TS continue for southern ME and eastern NH into early evening. Some of these may contain gusty winds. MVFR and IFR ceilings quickly build later this afternoon across the foothills and down to the Midcoast. These continue overnight, but slowly erode west to east as cold front swings through. Terminals N and W of the Whites likely remain locked in IFR stratus with incoming NW flow through Saturday. Long Term... Generally VFR conditions thru the extended. Some local MVFR is possible in showers in the mtns...but at this time HIE may be the only TAF site with a chance at rain Sun or Mon. Otherwise local IFR or lower in valley locations where fog is expected. Given the dry weather this may stay limited to HIE and LEB. && .MARINE... Short Term...Cold front clears the coastal waters by Saturday morning with showers and thunderstorms this afternoon. Upper low will continue WNW winds over the waters Saturday and Saturday night. Long Term...Ridging and surface high pressure will build in and dominate weather thru next week. As a result winds and seas are expected to remain below SCA thresholds. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Cornwell SHORT TERM...Cornwell LONG TERM...Legro AVIATION...Cornwell/Legro MARINE...Cornwell/Legro