Area Forecast Discussion
Issued by NWS Portland, ME

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
465 FXUS61 KGYX 291031 AFDGYX Area Forecast Discussion National Weather Service Gray ME 631 AM EDT Sun Jun 29 2025 .SYNOPSIS... A cold front crosses through northern New England this morning. High pressure builds through Monday, bringing mostly dry conditions and a warming trend. Low pressure tracking through Quebec will drag a cold front across the area Tuesday bringing chances for thunderstorms, a few of which may be on the stronger side. Outside of some mountain showers, the middle to second half of next week looks mostly dry and seasonably warm. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
6:30am Update... A cold front moves through over the next few hours, with clearing underway from west to east. The fog and low clouds is taking a little longer to clear out, so temps will be a little slower to respond this morning, but will quickly rise once the sun breaks through. Overall no major changes to the forecast at this time. Previous... One last batch of heavy showers and thunderstorms moves through the Lakes Region of Maine before sunrise this morning. A cold front associated with low pressure passing north of New England moves through during the morning hours today, bringing drier and warmer conditions. Fog and low clouds clear from west to east during the early to mid morning with the passage of the front. Temperatures quickly rise with sunshine and a west wind. Some upslope clouds and isolated showers linger in the higher terrain today, with more sunshine downwind of the mountains for the afternoon. Highs top out in the upper 60s to low 70s across the higher terrain, while 80s are expected downwind of the mountains. After an initial warm up to around 80 degrees along the coast, a sea breeze likely moves in by the mid afternoon as broad high pressure expands across the Gulf of Maine, dropping temps back into the 70s.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Broad high pressure continues to build across New England tonight, bringing mainly clear skies through the overnight. Dew points remain in the mid 50s to low 60s across the region overnight, so radiational cooling will be limited as lows are held in check by the dew points. This set up does favor areas valley fog, especially across the interior. Temperatures continue to warm tomorrow as ridging builds across the Northeast, and high pressure moves off the East Coast. Upper 80s to low 90s are expected across much of the interior, with low to mid 80s across the north. A seabreeze develops again tomorrow, likely starting by late morning, and keeps highs capped in the 70s to low 80s along the coast. Everyone enjoys mainly sunny skies, with only fair weather cumulus clouds expected across the higher terrain. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Pattern Overview: Our weather pattern looks to remain on the unsettled side as we end up in broad troughing for much of next week at the 500 mb level with a series of surface fronts as well. Global models are hinting at a sharper trough toward the July 4th holiday, but also a bit of a drier airmass that could limit shower activity. Impacts and Key Messages: * Tuesday is a day to watch as warm moist conditions ahead of a cold frontal passage may lead to the development of some stronger thunderstorms and heavy rain. Tuesday and Wednesday: As the ridge shifts off to the east, flow becomes southwesterly which looks to drive dewpoints up in to the upper 60s to near 70. This would have some locations feeling sticky with actual temperatures in the mid to upper 80s south of the mountains, feeling more like low to mid 90s. Southeastern New Hampshire may even approach Heat Advisory criteria if trends hold. Other than a little bit more of an uncomfortable day, this heat and humidity may provide forcing for some stronger thunderstorms later on Tuesday as a cold front approaches the area. The latest Long Range Ensemble Forecast has stayed pretty consistent with 1500-2000 J/kg of MUCAPE and 30-35 kts of deep layer shear, suggesting some organized convection as forcing for ascent increases ahead of the front. Current PWATs are modeled to be around 2", so these storms may contain heavy rain at the very least. Any finer details will have to be resolved by CAM guidance later down the road, but this certainly remains a period to watch. Skies clear behind the front, but 850 mb temperatures remain warm so Tuesday night looks like another night in the 60s for low temperatures. Wednesday looks like a drier day for the majority of the area with a more westerly flow maybe supporting showers in the mountains, similarly another front looks to approach in the afternoon bringing about a chance for a rumble of thunder as well. Thursday-Saturday: Models are in surprisingly good agreement that a sharper trough looks to approach the region late week. Where they differ is time of departure, with the GFS being the quickest and the Euro and Canadian keeping in under the influence of the trough through Saturday. Another thing of note is that the airmass around this time looks fairly dry so don`t assume your holiday weekend is going to be a wash. There is still a lot of time for things to change, but my forecast remains on the optimistic side (and close to NBM consensus) with just isolated to scattered showers at this time. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... Short Term...LIFR to IFR conditions quickly return to VFR this morning with the passage of a cold front, with VFR then prevailing through the remainder of the day. Valley fog likely develops tonight at LEB, HIE, and CON, but is possible at all terminals. Any fog clears tomorrow morning, with VFR prevailing through the daytime. Long Term...VFR prevails most days through Thursday, with the exception being on Tuesday when a cold front brings with it a chance for thunderstorms and heavy rain, and therefore brief restrictions. Some fog development is possible Monday night as moisture increases, and again Tuesday night at terminals that see rain. && .MARINE... Short Term...Conditions remain below SCA levels as a cold front crosses the waters this morning. High pressure then builds across the waters through tomorrow. Long Term... A cold front looks to cross the waters Tuesday night, which may bring about brief SCA conditions and chance for thunderstorms in the afternoon and evening. Sub SCA criteria then returns through Thursday. Flow will remain generally southwesterly. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Clair SHORT TERM...Clair LONG TERM...Baron