Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 241127 AFDGYX Area Forecast Discussion National Weather Service Gray ME 727 AM EDT Thu May 24 2018 .SYNOPSIS... A warm front will move north across the area later today and tonight. This will lead to very warm conditions on Friday. A cold front pushes in from the northeast late Saturday, providing a chance of showers and making Sunday much cooler. Cool and cloudy conditions linger into Monday, before we start to see it warm up during next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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7am update... Fog and low ceilings have lifted in all but the coast from Portland to Penobscot bay. Have updated the cloud cover and temperatures. Prev disc... Overnight some pockets of fog has formed as the moisture is trapped in the valleys. This will quickly erode as the sun continues to rise. Warm air will move into the region today as high pressure pushes in from the west. Along with the warming temperatures come decreasing dewpoints as the airmass to our west is quite a bit drier. Have dropped dewpoints a bit today as upstream observations and the potential to mix out to around 850mb will result in increased drying. Also a few wind gusts to around 20mph are possible. Along the coast, a robust seabreeze will develop and move inland as far as Sebago Lake and Lewiston by early afternoon. This will keep the high temperatures along the coast in the 60s while inland locations reach the 70s.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Overnight will see mostly clear skies with lows in the upper 40s to low 50s across the region. For Friday the high pressure continues to push in and the resulting west flow will bring downsloping winds. Once again expect good mixing so some wind gusts to around 20mph are possible. With the temperatures aloft climbing to +14C at 850mb and good mixing virtually all of the area will reach the 80s and 90F is possible in the Manchester to Nashua corridor. The front begins to retreat back down from the St. Lawrence on Friday night brining a slight chance for thunderstorms along the Canadian border. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... For the most part cooler air aloft continues to retreat pole ward across NOAM and environs, and ridging noses northward across the central part of the continent toward Hudson Bay by the middle of next week. So, while it looks good for an overall warming trend in the larger scale and the long range, will have to deal with back door front this weekend, which will make things quite cool Sunday into Monday. W-SW flow should persist thru Friday night, so mins will on the milder side, mainly in the upper 50s to mid 60s. Initially the front will be just N of the CWA, which will provide a threat of showers in the north, but these should hold there thru most of the night before a wave passing to the north start pushing that front south. Saturday is a bit tricky, especially for max temps, as the timing of the fropa will ultimately determine how warm it gets. I think most spots should see mid 70s to mid 80s before the front moves in, but the ME mtns and central ME could be limited to to the mid 60s to around 70. Once that front goes thru and winds shift to NE, probably in the afternoon in the ern zones and along the coast east of PWM, temps will drop off quickly and noticeably. For the rest of the CWA, the front will cross during the evening. Should be enough instability ahead of the front across southern zones that a chance of thunder should be in the forecast for Saturday afternoon into evening across srn NH, with a threat of showers continuing across all but the NE zones Sat night. Sunday and Monday look cool and cloudy with a chance of showers, and maybe some DZ at times closer to the coast as onshore flow persists into Monday morning. Highs Sunday will be 60-65 inland areas, and in the mid to upper 50s on the coast with cloudy skies. Sunday will see clouds, spotty DZ and the chc of showers continue with lows mostly in the 40s, except low 50s in srn NH. Monday may see a little improvement away from the coast, as the onshore flow weakens and flow aloft shift more westerly. It still looks mainly cloudy, and there`s a chance of showers, with highs in the 60s, but closer to 70 in inland areas of NH, but closer top 60 on the coast. A decent 500 mb wave approaches Monday night and will cross the region Tuesday, which should bring a front through and shift the flow to NW. This should allow us to mix down the warmer temps aloft /around 10 C at 850 MB/, which will push highs into the 70s, to near 80 in the warmer spots. 500 MB ridging begins to settle in during the middle of the week, with mainly dry and warm conditions Wed-Thu. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term... Generally VFR conditions across the region. A few patches of IFR/LIFR ongoing in the mountains as of 4am will lift after sunrise. For coastal sites, expect a strong seabreeze this afternoon. Friday will again by VFR but with continued west flow keeping the seabreeze at bay. VFR conditions expected tonight through Thursday night. However, there will be some patchy inland valley fog over eastern areas tonight with localized MVFR or IFR conditions along and near the Penobscot River Valley. Long Term... Mainly VFR Friday night into Sat. Expecting IFR cigs to develop Sat night and likely linger thru Sunday into Sunday night. Improvement to MVFR or VFR possible at inland terminals on Monday. && .MARINE... Short Term...Winds will be fairly calm today but we`ll see increasing southerly flow tonight as an east west pressure gradient sets up across the region. This will result in gusts to 25kts on the outer waters with waves building to 5-7ft through the midcoast and a Small Craft Advisory has been issued. Long Term... Lingering SCA conds Fri night should diminish by Saturday morning. May need another SCA in NE flow on Sunday. && .FIRE WEATHER... The next two days will see generally hot and dry conditions. Today Min RH values will fall to 20-25% across the interior. Along the coast a seabreeze will keep moist air in place. While there will be good mixing the fairly weak upper level flow should keep winds in the 15-20mph range- just below Red Flag criteria. Nevertheless with 10-hr and 100-hr fuel moistures less than 15% across portions of the area the dry conditions present an increased risk for any fire activity and an SPS has been issued to highlight this across inland areas. Friday will be similar to today with temperatures climbing even warmer. West flow will dominate keeping a sea breeze at bay and allowing the RH to fall to below 30% across much of the area. This will put southern NH near Red Flag criteria and will need to be watched for possible Fire Wx headlines. && .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...None. NH...None. MARINE...Small Craft Advisory from 11 PM this evening to 8 PM EDT Friday for ANZ150-152-154.
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&& $$ SYNOPSIS... NEAR TERM...Curtis SHORT TERM...Curtis LONG TERM...Cempa AVIATION... MARINE... FIRE WEATHER...

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