Area Forecast Discussion
Issued by NWS Portland, ME

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142 FXUS61 KGYX 232009 AFDGYX Area Forecast Discussion National Weather Service Gray ME 309 PM EST Fri Feb 23 2018 .SYNOPSIS... As low pressure moves through Quebec, it will send a warm front through New England tonight. Expect some wintry precipitation as this moves through. A cold front moves through on Saturday but not before temperatures warm up into the 40s and 50s. The next storm system will bring more widespread precipitation on Sunday, with mainly snow or sleet being the dominant precipitation type. There is also a chance for some freezing rain or rain depending on the track. Fair weather returns for the first half of week as a ridge of high pressure slowly builds over the region. Another complex weather system affect the region Thursday and/or Friday. && .NEAR TERM /TONIGHT/... Low pressure tracking through Quebec sends a warm front across our area this evening. Expect warm advection style precipitation along and ahead of this feature with precipitation likely starting as snow or rain depending on low level temperatures. As the evening goes on, temperatures will warm aloft and may change things to freezing rain in areas that get below freezing at ground level. As a result, will keep the Winter Weather Advisory in effect. Do not expect substantial icing amounts, but it could be enough to make things slick. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... Although winds will be westerly behind the front on Saturday morning, the cold advection does not drop in from the north until later in the day. As a result, expect warm temperatures in the morning with good low level mixing. Generally 40s and low 50s. This should change Saturday afternoon and evening as colder air pours in from the north. && .LONG TERM /SUNDAY THROUGH FRIDAY/... The southerly flow ahead of a large area of low pressure moving northeast over the western Great Lakes will spread moisture into the region during the day Sunday. At the same time, high pressure over the Canadian Maritimes will funnel cold air into the region near the the ground. Precipitation will spread northeastward from southwestern New Hampshire, starting about daybreak, reaching all of western Maine by about noon. The forecast challenge continues to be precipitation type. The precipitation is expected to start as snow in all areas. However, as a wedge of slightly warmer air moves over the region at about 7000 feet aloft, the snow may mix with or change to sleet and possibly freezing rain. Below this warm wedge in the atmosphere, initially, there will be sufficient sub-freezing air to refreeze any melted or partially melted precipitation. However with time, the entire column of air will gradually warm to allow for a brief period freezing rain or rain. The other part of the challenge will be surface temperatures. The cold and dry flow from the high pressure center to the northeast will help suppress warming during the day, contributing to the possibility of freezing rain if temperatures aloft warm sufficiently to melt the falling snow or sleet before surface temperatures warm above freezing. At this time, models suggest that most of the precipitation across the region will fall as snow and/or sleet with the GFS leaning more toward snow with the NAM slightly warmer aloft leaning more toward sleet. Across southern sections of the area, the precipitation may briefly change to rain or freezing rain before ending late Sunday afternoon or evening. Farther north, the snow may mix with a brief period of sleet or freezing rain before ending. High temperatures Sunday are likely to be within a few degrees of freezing all areas, warming a few degrees as the precipitation comes to an end. Total snowfall amounts will likely be 1 to 3 inches along the coast, to 3 to 6 inches across the interior and foothills. The northern mountains may see somewhat less snow as overall precipitation amounts are lower. Skies should clear Sunday night with temperatures only cooling to the mid 20s north to near 30 south. A ridge of high pressure build across the area Monday leading to a mostly sunny day with rather mild temperatures mainly in the 40s across the region. The ridge should lead to dry weather for Tuesday and Wednesday, except in the mountains where snow showers are possible. Another weather system may affect the region Thursday or Friday with the possibility of rain and/or snow. Models are not consistent on the track of this storm with the European model keeping this system well out to sea. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... Short Term...Expect MVFR to IFR conditions with light precipitation this afternoon and evening for most areas, with improving conditions by morning. Long Term...IFR to LIFR conditions Sunday in a mix of snow, sleet, rain and possibly freezing rain. VFR conditions expected Monday through Wednesday. && .MARINE... Short Term...Southerly winds today shift to west tonight and the northwest on Saturday. Could see some gusts to 25 KT during this time period so will keep the Small Craft Advisory in place, although will expand it to Penobscot Bay and lengthen its duration over the outer waters. Long Term...SCAs likely Sunday and Monday, then winds and seas expected to be below SCA criteria Tuesday and Wednesday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory until 10 PM EST this evening for MEZ007>009-012>014. NH...Winter Weather Advisory until 10 PM EST this evening for NHZ001>006-009. MARINE...Small Craft Advisory from 6 PM this evening to noon EST Saturday for ANZ150-152-154. Small Craft Advisory from 6 PM this evening to 5 AM EST Saturday for ANZ151. && $$ NEAR TERM...Kimble SHORT TERM...Kimble LONG TERM...Jensenius is the U.S. government's official web portal to all federal, state and local government web resources and services.