Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 190318 AAC AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 1018 PM EST Wed Jan 18 2017 .SYNOPSIS... Low pressure will pass through the region tonight with some additional light snow. High pressure will build in for the remainder of the week, with above normal temperatures expected into Monday. A storm system may affect the region beginning Sunday night and continuing into early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 1015 PM Update... Additional light snow is falling in association with a short wave moving through Quebec and into northern Maine. The atmosphere remains saturated below 700 mb so orographic lift will be squeezing out an additional inch or so overnight. Have removed drizzle from the forecast as profiles are also becoming too cold for it with the approach of the short wave. 630 PM Update... Minor ocean effect snow is still falling from Portland to the New Hampshire seacoast. Additional showers have developed over the foothills ahead of a short wave disturbance. Not expecting anything but minor accumulations so have cancelled the winter weather advisory. Patchy freezing drizzle also a possibility for southern NH and SW Maine and will be issuing a Special Weather Statement to cover this hazard as amounts will be extremely light. Temperatures were adjusted slightly as well as weather grids... overall forecast is on track. Previous discussion... Overall, the coverage and intensity of snowfall has lessened across the forecast area, and has ended in many places. Therefore, a large portion of the winter weather advisory was cancelled. However, we have left the the advisory going for coastal portions of York, Cumberland, and Rockingham Counties as an ocean enhanced band continues to occasionally produce moderate snowfall and some accumulations. Therefore, a slippery afternoon commute is likely, especially on untreated roadways. That advisory will expire at 6 PM unless it is determined it needs to be extended. Patchy light freezing drizzle is possible at times this evening as well, mainly across southern zones that are below freezing. We are not seeing this threat as widespread at this time, and especially since roads have been treated for the earlier snowfall. Therefore, will cover this threat with a special weather statement instead of an additional advisory. Later tonight, another short wave trough will approach from the northwest. The moisture availability and forcing for ascent will be sufficient for a another period of light snow across mainly the northern 2/3rds of the CWA...with an additional 1 to 2 inches possible mainly between midnight and 6 am. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... The short wave trough moves off the the east Thursday morning allowing for a return to fair weather and warmer than normal temperatures. High pressure then builds in Thursday night. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... A ridge will move overhead Friday. A weak shortwave will shear out south of the forecast area Friday night and early Saturday. This will likely result in some clouds especially in the southwest portion of the forecast area but no precipitation is expected as this feature will be weakening. Ridging aloft will move in for Sunday but high pressure will build in from the northeast Monday and this high will set the stage for what may be a messy storm Tuesday into Wednesday. There may be enough cold air in the interior to have precipitation start ans snow and then transition to a mixed bag. The change to rain should be fairly quick along the coast and in southern New Hampshire but interior portions of western Maine and New Hampshire might be a different story. Forecast confidence is low at this time. There could be copious amounts of precipitation with this so precipitation type will be important as we may have to watch for the possibility of some urban type flooding or even the chance of river ice movement. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Short Term...IFR/MVFR cigs/vsbys continue this evening, mainly on the coastal plain. A brief period of improvement is expected before another round of light snow after midnight brings them down again for a few hours before 12z Thursday. VFR conditions return Thursday and Thursday night. Long Term...Expect VFR conditions Friday through early Monday. Conditions begin to deteriorate late Monday to IFR. && .MARINE... Short Term...SCA conditions likely into Thursday morning, with them possibly continuing into Thursday night on the outer waters. Long Term...SCA for seas possible early Friday. then quite on the waters through Sunday. Winds and seas build with an increasing east to southeast flow. Gales might be needed for Tuesday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 4 AM EST Thursday for ANZ153. Small Craft Advisory until 3 PM EST Thursday for ANZ150-152- 154. && $$ NEAR TERM...Hanes SHORT TERM...Ekster LONG TERM...Hawley is the U.S. government's official web portal to all federal, state and local government web resources and services.