Area Forecast Discussion
Issued by NWS Portland, ME

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193 FXUS61 KGYX 171405 AFDGYX Area Forecast Discussion National Weather Service Gray ME 905 AM EST Sat Feb 17 2018 .SYNOPSIS... High pressure over the region will result in a pleasant winter day. Quick moving low pressure will move south and east of New England Tonight and early Sunday, bringing the potential for snow...particularly over southern New Hampshire and the coast of Maine. As we move into next week...a warming trend is expected with temperatures moving well above normal...especially Tuesday and Wednesday. Expect some rain late Monday into Tuesday and again Wednesday Afternoon. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 900 AM...At 14z a 1031 millibar high was centered over northern New England...with GOES imagery showing clear skies across the region. For this ESTF update...I ingested the mesonet into near term grids. Prev Disc... Update...Quick update to tweak temperatures. No other changes. Previous Discussion...A nice day on tap today with sunshine and temperatures a bit below normal for the time of year. Clouds will be increasing later this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Models are in fairly good agreement on taking a surface low rapidly northeast tonight from off the mid atlantic coast to south of Nova Scotia Canada by 18Z Sunday. Snow will quickly overspread the region from southwest to northeast this evening. Snow will breakout first in southern New Hampshire just after 00Z and will be into Portland by 03Z-04Z. A quick 6 to 8 hour snowfall. Plenty cold enough to keep precipitation all snow. Have issued winter weather advisories for southern New Hampshire and southwest Maine. We were initially going to leave out Strafford county and interior York county but the southern portions of those zones may approach 4 inches so we decided to include them. It is possible that mid coast Maine could reach advisory criteria of 4 inches but for now have not issued winter weather advisories there. Snow will move out quickly Sunday morning with sunny skies and temperatures rising into the lower 40s. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Global models are in good agreement that a significant warm up will occur during much of the extended forecast period as a large upper level ridge develops along the east coast. In the dailies, high pressure over the Northeast will move offshore Sunday night. On the backside of this high a significant southerly flow will develop. A vigorous warm front moving north in this flow will result in a period of rain late Monday into Tuesday. Over Mountain areas temperatures will initially be cold enough for mixed precipitation. With the warm front north of most of the area Tuesday Afternoon and Wednesday much above normal temperatures are expected. Tuesday`s record highs will be tough to reach...however we have a chance of reaching near record to record high temperatures on Wednesday. ***Records for PWM & CON*** TUE WED PWM 61/1994 59/1953 CON 66/1930 64/1872 A cold front will approach the region late Wednesday and cross the area Wednesday Evening. This will bring with it a chance of showers. Cooler high pressure will nose in from the Great Lakes region on Thursday into Friday. A warm front will approach late Friday as the high moves offshore. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... Short Term... Long Term...VFR to MVFR conditions Sunday Night into Monday. Areas of IFR/LIFR possible Monday Night into Tuesday as a warm front approaches and crosses the region resulting in a period of rain and fog. && .MARINE... Short Term...Winds are dropping quickly on the waters as high pressure builds in today. Winds will increase tonight from the south as will seas. A small craft advisory may be needed tonight. Long Term...Increasing southerly winds will result in wind and waves approaching SCA levels late Monday and Monday Night. While winds will go blo SCA levels...seas will remain above SCA levels Tue and Wed. && .HYDROLOGY... We will have to watch the rivers closely next week as the warm weather and some rain may lead to enough runoff to cause ice jam flooding. There are several locations with ice jams in Maine and New Hampshire. Looks like a 72 hour period or longer with temperatures remaining above freezing. It is possible that the warmer weather will weaken the ice so that any rise in river levels will just move the ice harmlessly downriver. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory from 7 PM this evening to 7 AM EST Sunday for MEZ018-023. NH...Winter Weather Advisory from 7 PM this evening to 7 AM EST Sunday for NHZ010>015. MARINE...None. && $$ ES is the U.S. government's official web portal to all federal, state and local government web resources and services.