Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
644 FXUS61 KGYX 152328 AFDGYX Area Forecast Discussion National Weather Service Gray ME 628 PM EST Mon Dec 15 2025 .SYNOPSIS... High pressure builds in from the southwest tonight and settles south of New England through Wednesday. A cold front will pass north of the area Wednesday afternoon bringing chances for snow showers in the mountains. Temperatures warm well above normal Thursday into Friday ahead of a strong cold front. This front will bring a period of rain Thursday night into Friday along with gusty south winds. Gusty west winds behind the cold front will bring cooler conditions into the weekend. && .NEAR TERM /THROUGH TUESDAY/... 630 PM Update... Minor changes to reflect latest observational trends. Gusty winds will continue to gradually diminish through the remainder of the evening with temperatures cooling into the single digits and teens. Previously... A breezy morning was experienced across northern New England, with gusts up to 20mph in many locations. Winds look to trend calmer this afternoon, as the pressure gradient starts to loosen and and pressure rises gradually. A very weak disturbances moves in from the west, bringing increased cloud cover this evening. Calm winds may trigger some radiational cooling in spots with clearer skies, though partly cloudy skies across the region will make this inefficient and will keep low temperatures in the lower teens tonight. In addition, a stray snow shower can not be ruled out in the mountains with some residual moisture stemming from the aforementioned weak disturbance. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... An H5 ridge quickly moves in Tuesday morning, and should help warm the entire thermal column. This, in addition to clear skies through the day will allow for a sunny, bluebird day on Tuesday, with temperatures markedly warmer than what we have been experiencing recently. Temperatures look to be in the mid-20s across the mountains and even into the mid-30s along the coast. Tuesday night will remain dry as a disturbance passes New England to the north. Lows should be warmer as well, with upper teens and lower 20s expected Tuesday night. && .LONG TERM /THURSDAY THROUGH MONDAY/... Overview: A cold front will scrape northern zones Wednesday bringing chances for snow showers in the mountains. High pressure builds in from the south Wednesday night and shifts southeast Thursday allowing the warming trend to continue. Low pressure tracks ENE across Quebec Thursday night through Friday bringing a period of rain followed by rain changing to snow in the mountains as a strong cold front crosses. High pressure briefly builds in Friday night into Saturday morning before a clipper system brings changes for light snow Saturday night. Key Messages: *Rain on snow is likely Thursday night into Friday. No flood impacts are anticipated due to antecedent low river flows and fast moving nature of the system. Some poor drainage/ponding of water will be possible during the Friday morning commute. *Southerly winds ahead of the cold front could gust up to 45 mph along the coast late Thursday night through Friday morning. Forecast Details: Low pressure passes well to the north Wednesday with deep SW flow leading to temperatures warming above normal. The trailing cold front will sag into northern zones Wednesday afternoon and will provide enough forcing for some snow showers in the mountains. High pressure builds in from the south Thursday with warmer air marching back northward through the day. Highs on Thursday will reach the mid 30s near the Canadian Border and into the mid 40s across the south. The latest available NWP guidance suggests any precipitation associated with the low pressure system approaching from the Great Lakes will hold off until Thursday night. Warm air and moisture advection will ramp up Thursday night as low pressure south of James Bay deepens. A robust SSW low level jet will develop ahead of this system and slide east across the area between midnight and noon Friday with winds at 925 mb approaching 60 kts. BUFKIT profiles suggest the orientation of the LLJ and a shallow inversion will limit the full potential of these winds mixing to the surface with peak gusts forecast up to 45 mph along the coast and 30-40 mph inland. PWATs will climb to over 1 inch, which will be 2-3 STD above normal for this time of year. Temperatures will likely be above freezing across much of the area when rain breaks out Thursday night. The high PWATs will favor bouts of moderate to heavy rain late Thursday night into Friday morning. Fortunately this system will be fast moving with ensemble mean QPF generally around 0.75 inches. This rainfall combined with anticipated snow melt will likely not be high enough to lead to any flooding other than poor drainage issues Friday morning into early afternoon. The attendant cold front will sweep across the area Friday afternoon. Rain will taper to showers south of the mountains where temperatures will still be above freezing into Friday evening. Colder air aloft will work into northern zones allowing rain to change to snow in the mountains with light accumulations possible before precipitation ends Friday evening. There will be a period of gusty west winds Friday night in the wake of the cold front. High pressure builds in Saturday morning allowing winds to subside with mostly fair weather. A clipper system races across SE Canada Saturday evening bringing chances for light snow Saturday night. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Short Term...No restrictions are expected this afternoon through Wednesday morning. Low VFR/high MVFR CIGs can not be ruled out this evening through tomorrow morning in HIE. Long Term...Mainly VFR Wednesday into Thursday. Clouds thicken and lower Thursday night with periods of rain likely bringing restrictions through Friday morning. A SSW LLJ will bring the potential for LLWS Thursday night into Friday morning. Winds shift out of the west Friday afternoon with improving conditions Friday night into Saturday. && .MARINE... Short Term...Small Craft conditions are expected this afternoon, with westerly winds gradually diminishing through the evening. Seas of 4- 7ft are expected, diminishing to 2-4ft by tomorrow morning. Westerly sub-SCA winds continue through the day on Tuesday, and strengthen Tuesday evening. Seas of 2-4ft are expected through the day Tuesday, with strengthening seas expected Tuesday night. By Wednesday morning, gale force northeasterly winds are possible and seas could be as high as 6-10ft. Long Term...SW winds will gust to Gale force Wednesday as low pressure passes north of Maine. Winds and seas drop below SCA thresholds Thursday morning. South winds ramp up late Thursday with Gales likely Thursday night into Friday. Winds shift westerly behind a front that crosses Friday evening with westerly Gales likely into Saturday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 1 AM EST Tuesday for ANZ150>154. && $$ NEAR TERM...Palmer/Tubbs SHORT TERM...Palmer LONG TERM...Schroeter