


Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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149 FXUS61 KGYX 070240 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1040 PM EDT Tue May 6 2025 .SYNOPSIS... A cut-off low continues northward this evening, bringing showers and thunderstorms. Fog is likely tomorrow morning, and will stick around through the day tomorrow along the coast. Relatively warmer and drier conditions return, but showers are likely tomorrow and Thursday. Rain and cooler conditions return with the next low pressure system for Friday into Saturday. Warmer and drier conditions return with High pressure for Sunday and early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1040 PM...Minor update to PoPs and temperatures to reflect the latest observed trends. Latest radar shows scattered showers moving south to north across eastern New England with this shower activity expected to diminish over the next few hours. 655 PM Update...Going forecast is in good shape and have mainly refined PoPs based on latest observations. Two areas of showers are moving NNE across the area with one moving over Maine mountains and central Maine and the other moving through southern NH. Recent runs of the HRRR have additional areas of showers blossoming over the area through midnight with PoPs then decreasing through the rest of tonight. Many areas south of the mountains are experiencing fog at this hour and will have to monitor for the development of dense fog later tonight along the coastal plain. Previously... Currently, an occluding surface low is situated over the Great Lakes. As this low nears New England, an attached occluded front will move northward, overtaking a warm front. The front will bring showers and thunderstorms through the remainder of the evening. Guidance has generally continued to trend drier with these showers and storms, with rain totals likely not exceeding an inch of rainfall through tomorrow morning. Southerly flow tonight will allow for the coast and much of central ME to stay in the fog/low-stratus tonight. Lows tonight should be in the lower 50s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Fog will break up across the interior by the late morning hours tomorrow, but light, onshore flow will help keep fog hanging on along the coast. The aforementioned low`s center arrives in New Hampshire tomorrow afternoon. The clearer skies across the interior will help destabilize the atmosphere, potentially allowing for some convective initiation tomorrow afternoon. The environment is not conducive to strong storm development, and forecast soundings suggest these will be ordinary pulse thunderstorms that pose little impact other than perhaps some isolated gusty winds. These storms should be across NH in the afternoon, with storms weakening and moving out of the area tomorrow evening. Fog may back-build right back into central ME tomorrow night as light southerly flow could allow for more marine fog to advect inland. Most fog should mix out by the AM commute on Thursday. && .LONG TERM /THURSDAY THROUGH TUESDAY/... 1040 PM Update...No significant changes noted in the latest NBM. Another widespread soaking rain is likely Friday into Friday night as slow moving low pressure crosses the region. The NBM favors a warming and drying trend over the weekend into early next week. Overview... The slow moving upper level low currently across the Northeast moves into the Canadian Maritimes on Thursday. Another upper level low deepens across the eastern Great Lakes by late Thursday, and slowly moves through the Northeast on Friday and Saturday. High pressure begins to build in on Sunday, and persists into early next week with a warming trend. Details... Thursday features more sunshine south of the mountains with a northwest flow, and more clouds and cooler temperatures through the higher terrain. Highs warm into the 60s downwind of the mountains, with low 70s into southeast New Hampshire. Cooler conditions with some scattered afternoon showers are likely across the north with highs mainly in the 50s. By Friday, the next upper level low approaches from the west, with a surface low likely developing and bringing another batch of showers into the region for Friday. Cool, cloudy, and raw conditions are expected Friday as highs remain in the 50s. Depending on just how organized the surface low can become, there is the potential for some heavier rainfall amounts. Similar to this past system, this would likely be more localized and convective in nature, so we`ll have to wait a little longer to get into the high res model guidance window to try to pin down these areas. Saturday features slowly improving conditions as the low slowly transits through New England. Scattered showers are still likely, but more breaks of sun should allow temperatures to reach into the 60s by Saturday afternoon. Sunday marks the start of a warmer and drier pattern as high pressure builds into the Northeast. Another cut off low likely develops, but this time across the southern US, with ridging building north of the low. This directs a warmer airmass north of the low and into New England on a westerly flow. Temps warm into the 60s to low 70s on Sunday, with more widespread 70s on Monday. At this point, Tuesday looks even warmer as highs warm into the mid to upper 70s across much of the area. However, it`s wise to be suspicious from this far out at this time of year as a back door could easily keep temps cooler as high pressure moves offshore. So we`ll continue to monitor the progression of this warm up over the next few days. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Short Term... Fog, showers and thunderstorms should keep restrictions down through the remainder of the evening. Once the storms move out, fog and low stratus will build in, keeping restrictions down through tomorrow morning. Rain and thunderstorms keep restrictions down tomorrow afternoon. Tomorrow night, southern NH goes to VFR as skies start to clear out. However, fog builds back in everywhere else, keeping restrictions down across coastal and Maine sites. Long Term...Mainly VFR are expected on Thursday, with brief showers and MVFR conditions possible at LEB and HIE. Conditions then lower to MVFR and IFR Thursday night and Friday with periods of a rain and fog. Conditions gradually improve on Saturday, with VFR returning by Sunday and persisting into early next week. && .MARINE... Short Term...Southerly flow at 9-18kts is expected through tomorrow night. Winds shift to southwesterlies by Thursday morning. Seas remain below SCA thresholds and stay steady at 2-4ft through Thursday morning. Long Term...A broad area of low pressure slowly approaches the waters on Thursday and Friday, and moves east of the waters Saturday night and Sunday. Some marginal SCA conditions are possible during the Friday and Saturday timeframe from this system. High pressure builds in for late Sunday and early next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Palmer/Schroeter SHORT TERM...Palmer LONG TERM...Clair/Schroeter