Area Forecast Discussion
Issued by NWS Portland, ME

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115 FXUS61 KGYX 251103 AFDGYX Area Forecast Discussion National Weather Service Gray ME 703 AM EDT Fri May 25 2018 .SYNOPSIS... High pressure moves offshore today and increasing SW flow west of this system will produce breezy and very warm conditions today into tonight. A cold front pushes in from the northeast on Saturday, providing a chance of showers or thunderstorms and making Sunday much cooler. Cool and cloudy conditions linger into Monday, before we start to see it warm up during next week. Canadian high pressure to bring dry conditions back to the region Tuesday through Thursday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 7 AM...Other than some cirrus work across the SW zones, forecast looks good. Still in store for a very warm and windy day. Previously...High pressure building to our south and weak low passing to our north will provide a warm westerly flow today , with +15C 850 temps advecting in and mixing down. Sfc winds look generally westerly, which should warm up most places in our CWA into the 80s, with 90 F possible in some of the warmer spots. The west winds will gust to 25-30 mph at times as well, but skies remain mainly sunny with some cirrus moving in late. This will create favorable meteorological conds for fire growth, and this is discussed further in the fire weather section. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... That weak will pass to our N this evening, and good produce a few showers or thunderstorms along the intl border, as cold front approaches from the N. The better ch for showers will come after midnight, as another wave move Se into the St. Lawrence valley and could bring some showers into NH and interior west/central ME. It will be warm and muggy night as dew points rise and persistent west flow keeps temps in the 60s across most of the CWA. On Saturday, that second wave will pass across the nrn part of the CWA and push the cold front SSW across the area. Some showers are possible in the morning in all but the srn part of NH and far SW ME, but the front will not really progress SW until the afternoon. So highs in srn NH will be in the mid to upper 80s, while they will only be 70-75 along the ME coast and the ME coastal plain, and only in the upper the 60s in the ME mtns. Some t-storms will possible in the srn half of NH and parts of wrn ME outside the mtns as the front pushes thru. That front will be quite noticeable as it pushes SW along the coast Saturday after noon, when temps drop from the mid to upper 70s to the low to mid 60s in a short period as the flow quickly shifts onshore, and could become briefly gusty. Srn NH looks like it should hold onto to the warmer thru much of the afternoon, but could see that front push thru late in the day or early evening. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... High pres over the maritimes will continue to push south driving the cold front south of the southern New England coast Sat night. As the large ridge of high pres becomes better established over the maritimes it will allow a deeper moist east flow to develop with the nosing of the high across the region, which is well advertised on the models. This ridge of high pres will remain anchored over the maritimes through the rest of the holiday weekend as a weak wave of low pres moves east along the stalled frontal system located south of New England. This combination will produce a cool, damp, moist east flow with sct light showers at times through Mon. By Sun afternoon areas of fog and patchy drizzle will also develop over southern areas and then move north Sun night and Mon. QPF amounts from this system will be very minimal. An upper short wave will move through the area Mon night with a drier northwest flow at the sfc/aloft to develop in its wake. This will allow clearing later Mon night with a very dry air mass and warmer temps to return midweek. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... Short Term...LLWS should end after sunrise as we start mixing the strong W flow down to the sfc, and W winds gust to around 25 kts today. Mainly VFR at the terminals thru tonight. Will start to see flight restrictions develop in low cigs as a cold fronts moves across the area from NE-SW on Saturday. Long Term...IFR/lifr ceilings in developing stratus/patchy fog Saturday night in southern New Hampshire and southwest Maine. Areas of MVFR/IFR ceilings in southern zones Sunday. Widespread IFR/LIFR ceilings/vsby Sunday night and continuing through Monday, then becoming VFR Monday night. VFR Tuesday. && .MARINE... Short Term...SCAs remain in effect today for all but Casco Bay as west wins gust to 25 kts or so. These will diminish tonight. A cold front cross the waters Sat afternoon from the NE, and could see a brief burst of SCA gusts Saturday afternoon behind the front. Long Term...East winds will remain below SCA conditions but with a long and persistent easterly fetch, the seas are expected to build to 4-7 ft over the outer waters Sun and continue through Mon so an SCA will be likely needed for that time period. && .FIRE WEATHER... A strong westerly gradient will develop today, preventing a sea breeze from forming and allowing the RH to fall to below 30% across portions of the area. Through collaboration on the fuel and green up conditions with Maine and New Hampshire, have opted to issue an SPS for both states for the elevated fire weather conditions. Winds diminish with good recovery tonight. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ150>152-154. && $$ SYNOPSIS... NEAR TERM...Cempa SHORT TERM...Cempa LONG TERM... AVIATION...Marine MARINE... FIRE WEATHER...

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