Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 252305 AFDGYX Area Forecast Discussion National Weather Service Gray ME 605 PM EST Sun Feb 25 2018 .SYNOPSIS... Low pressure will track northeast this evening bringing an end to the precipitation across the region. High pressure will build east from the Ohio Valley tonight through Tuesday. A weak cold front will cross the area late Wednesday or Wednesday night. A complex low pressure system will affect the area Thursday night and Friday. && .NEAR TERM /TONIGHT/... 6PM UPDATE... Will update the forecast primarily to drop the Winter Weather Advisory as snow is ending. Will also adjust temperature forecast over the next few hours based on latest observations. ORIGINAL DISCUSSION... Precipitation is starting to come to an end from west to east as low pressure continues to track northeast along the coast. Winter Weather advisories will be cancelled with this update package for New Hampshire and southwestern Maine while the eastern portion remains for a few more hours. Radar cc shows the warm air aloft has shifted back to the south leaving a straight rain/snow scenario for the next few hours. As precipitation ends and skies begin to clear low level moisture will linger allowing fog to form. Expect some patchy dense fog overnight. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... Fog will rapidly lift after sunrise Monday morning as west flow develops behind the departing system. This will lead to a few upslope showers in the mountains. A high froude number for the afternoon means a few of the showers may propagate over the mountains and into the foothills but the overall low coverage of shower activity means no significant accumulation is expected. As high pressure builds in to start the week temperatures will climb into the 40s across the region under light winds. Monday night will be clear and colder as high pressure remains in place. && .LONG TERM /TUESDAY THROUGH SUNDAY/... The ridge of high pressure over the area Tuesday will move offshore Tuesday night. Tuesday`s high temperatures will be mainly in the 40s across the region. As the ridge moves offshore Tuesday night, a cold front will drop slowly southeast from Canada and cross the region late Wednesday and Wednesday night. The frontal passage could be accompanied by a brief sprinkle or flurry in the mountains, otherwise, the front should pass through the remainder areas without any precipitation. Before the front passes, temperatures across northern areas will reach near 40 with southern New Hampshire reaching the low to mid 50s. On Thursday, low pressure moving southeast from the Ohio River Valley will bring the threat of precipitation to New Hampshire and southwestern Maine by late in the day as warmer air streams northward ahead of the system. Models have been flip-flopping on the track of this system. Latest GFS tracks the system much farther south with only limited impacts on just southern New Hampshire and southwestern Maine. In contrast, the latest European model has now shifted the storm farther north with more significant impacts, especially across southern section. In either case, the storm could produce strong northeast winds and building seas on Friday. Given the inconsistencies among models and the inconsistencies between runs of the same model, there is considerable uncertainty in the eventual track of the storm and any impacts. The low is forecast to move well out to sea Saturday. A ridge of high pressure will then build into the area for Sunday and Monday. && .AVIATION /23Z SUNDAY THROUGH FRIDAY/... Short Term...Snow will come to an end from west to east with ceilings returning to VFR in its wake. The increase in clouds will be short lived as many location drop to IFR in fog overnight. Fog will burn off after sunrise as VFR returns to start the week. Long Term...VFR conditions expected Tuesday into Thursday. Depending on storm track, IFR conditions are possible late Thursday through Friday, especially across southern New Hampshire and southwestern Maine. && .MARINE... Short Term...SCA remains in effect through tonight as onshore flow continues to gust around 30kts. Winds and seas will subside later tonight as the low exits the area. Long Term...Winds and seas are expected to be below SCA criteria Tuesday into Thursday. Increasing winds and seas are expected during the day Thursday. An intensifying storm off the mid- Atlantic coast Friday could produce gale force winds across the waters. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 7 AM EST Monday for ANZ150-152-154. && $$ NEAR TERM UPDATE...Kimble SHORT TERM...Curtis LONG TERM...Jensenius

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