Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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894 FXUS61 KGYX 210721 AFDGYX Area Forecast Discussion National Weather Service Gray ME 321 AM EDT Sun Jul 21 2024 .SYNOPSIS... A cold front continues to press south through the area today bringing the chance for scattered showers and a stray thunderstorm. The front settles south of the area Monday with high pressure bringing dry conditions. Moisture increases Tuesday with daily chances for showers and afternoon thunderstorms into Friday. Cooler conditions are expected for at least Wednesday and Thursday. High pressure looks to return for next weekend with warming temperatures. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Surface observations suggest a west to east oriented cold front has pushed into the mountains with winds turning northwesterly near the Canadian Border. Latest radar shows little in the way of precipitation with the front over the forecast area with better radar returns over northern VT where rain is reaching the ground. This front will continue southward through today providing a focus for mainly clouds as the 00Z model suite suggest little in the way of shower activity will occur over the area until mid day. The front will be pressing through the lakes region of NH and ME around mid day with CAMs suggesting shower activity will start to blossom near the front early this afternoon. The best chances (20 to 40 percent) for showers will occur along and south of a line from KLEB to KLEW between 1 PM and 4 PM. There will also be a few hundred J/kg SB CAPE present bringing the chance for a stray thunderstorm. Otherwise it will be mostly dry today with a mix of sun and clouds as the front crosses the area. Highs will range from the 70s north to mid 80s across the south. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... The cold front will be pushing offshore this evening with mostly clear skies for tonight. A drier airmass will moved into the area behind the front with dewpoints dropping into the 40s and 50s. Northwest winds behind the front will slacken tonight and with mostly clear skies lows will drop into the 40s north to 50s south. Fair weather looks to be in storm for Monday as the front stalls south of the forecast area with weak high pressure moving in from the west. Highs will range from the 70s north to 80s south, while onshore winds will keep coastal areas cooler than the interior. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Overview... A ridge builds into the Northeast as a near stationary front begins to drift northward through midweek. Increasing moisture from the building ridge brings increasing chances for showers and thunderstorms by Tuesday and Wednesday as the moisture interacts with the front, with shower chances continuing into Thursday and Friday. A stronger cold front pushes through late in the week, with high pressure building into the weekend and bringing drier conditions. Details... By Tuesday, the front begins to drift northward as a warm front, likely extending through the forecast area by the afternoon hours. Scattered showers and storms become more frequent by the afternoon hours near the front, but the exact location of the front at this time remains uncertain. Overall, the progression of the weather features have been trending slower on the ensembles as we get closer in time. This continues a trend we have seen over the last few weeks, and is not uncommon in the summertime as forcing and features are not as well defined compared to the cooler season. So currently central and interior areas look to see the most widespread showers and storms on Tuesday, but this will likely still need to be fine tuned over the next couple of days depending on the progress of the front. Scattered showers and cooler conditions are expected for Wednesday as the front lingers and mostly cloudy skies are expected. By Thursday, a weak wave of low pressure likely moves along the front and helps to enhance the shower and storm activity. This looks like the best chance for the threat of some heavier rainfall, especially in any areas that get worked over in the previous couple of days. Friday is where the slowing of the weather pattern since yesterday shows up most, with chances for showers continuing. Should the speed of the low`s progression be slower, Friday could end up even wetter. With it still being almost a week away, it`s too early to sort out any details with this feature, but the trend for now is that it would be slower to depart. Then by next weekend, high pressure begins to build in from the west behind a more well defined cold front that helps clear out the moisture. Temperatures also begin to rise again by next weekend with this increasing sunshine. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... Short Term...Mainly VFR will prevail today through Monday. A front dropping south through the area will provide a focus for clouds and scattered showers early this afternoon along a line from KLEB to KCON to KPWM so there will be a low chance for brief restrictions if a shower crosses a TAF site. Valley fog may develop tonight impacting KLEB and KHIE for a few hours early Monday morning. Long Term...There will be intermittent chances for restrictions with afternoon showers and storms Tuesday through Friday. Periods of marine fog and IFR conditions are also possible through coastal terminals during this time period. Conditions likely improve next Saturday as high pressure brings more steady VFR conditions. && .MARINE... Short Term...Winds and waves are expected to remain below SCA levels through Sunday night. Long Term...A front stalls across the Gulf of Maine and lingers for much of the week. Pressure patterns remain weak most of the week, keeping conditions below SCA levels. Areas of dense fog are possible at times Tuesday through Friday as the front lingers. High pressure then clears the fog by next weekend. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Schroeter SHORT TERM...Schroeter LONG TERM...Clair