Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KGYX 260133 AFDGYX Area Forecast Discussion National Weather Service Gray ME 933 PM EDT Sat Mar 25 2017 .SYNOPSIS... A cold front stalls south of the region this evening. High pressure builds in overnight from the north and will shift east on Sunday. A warm front will approach from the southwest on Sunday before a weak wave of low pressure forms and passes through the Gulf of Maine Monday. This will provide a round of mixed wintry precipitation Sunday night into Monday. Low pressure moves north of the region on Tuesday and drags a cold front through on Wednesday. High pressure will build in from Canada for the end of the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 920 pm Update: Skies have become clear across all forecast areas, even across southern areas of NH/ME. There are a few pockets of fog trying to form over southern/southeast NH where precipitation occurred into the late afternoon. Will mention patchy fog over southern areas. Light ventilation of dry air from the north should help dry out low levels some and prevent fog from becoming widespread the rest of the night. 620 pm update: Skies have cleared across all but southernmost areas of NH which will occur in the next hour or so as rapid clearing continues from the north. Made some adjustments to sky cover for early this evening based on clearing trends. After input of latest mesonet data no other changes were needed at this time. Previous Discussion: Bands of snow, some of them heavy will exit southern New Hampshire over the next one to two hours. Thereafter, Canadian high pressure will build southward, clearing skies across the region. Cooler and drier air will be filtering south and into Maine and New Hampshire. This will allow temperatures to fall into the single numbers in the north with teens and 20s further to the south. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Flow will become easterly on Sunday. This will allow for low level moisture to enter coastal areas and also portions of southern New Hampshire. Clouds will also be advecting into the region from the next system. Cloud cover appearing after a cold, clear night will keep some of the cooler readings in our region for this time of the year with highs mainly in the upper 30s. Sufficient easterly flow will allow for patchy drizzle to enter the region at some point during the day Sunday. By Sunday evening, synoptically driven precipitation will enter the region as low pressure head towards the Great Lakes. Cold air damming will continue however as high pressure remains to our north and east. Expect a coastal front to develop as well. Followed the cooler models for this package. Expect more in the way of snow and sleet over central and northern areas with freezing rain expected over southern and western New Hampshire as well as coastal Maine just inland from the coastal front. Some freezing rain may reach northern areas towards the long range portion of the forecast. Will update ice and snowfall maps to lean towards this cooler solution. Temperatures Sunday night will likely hold fairly steady. QPF looks to be slightly over a half inch for much of our area with several inches of snow over interior regions along with a coating of ice. && .LONG TERM /MONDAY THROUGH SATURDAY/... The models are in decent agreement on the longwave pattern into late next week. We begin the period with a shortwave impulse over the eastern Great Lakes. This impulse will weaken as it rides northeast across New England Monday into Monday night. At the surface...low pressure will ride northeast into Quebec with a warm front moving into southern and western New England. Models strongly hint that the warm front will hang up to our south with light overrunning precipitation for Monday and Monday night. A series of weak impulses will keep things unsettled for Tuesday. By Wednesday...digging shortwave impulse will close off over New England with a continuation of unsettled conditions. This low and associated surface system will exit into the maritimes during Thursday...with lingering clouds and showers confined to higher terrain as well as our eastern Maine zones. Ridging arrives just in time for a quiet end to the work week. Thereafter...considerable uncertainty exists in sensible weather details as medium range models show considerable spread in solutions. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... Short Term...VFR tonight. Conditions lowering to IFR and localized LIFR by Sunday night. There could be some LLWS developing Sunday night if the winds above the surface increase enough. Long Term... Mon...IFR with lcl IFR in rain with areas of sleet and freezing rain psb Mon at non-coastal taf sites. Tue...MVFR with areas of IFR in ceilings, -shra and fog. Wed - Thu...Areas of MVFR in -shra/-shsn. NW sfc wind gusting to 25 kt. && .MARINE... Short flags. Long Term... Mon...Small Craft conditions are likely. Wed - Thu...Small Craft conditions are likely. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... is the U.S. government's official web portal to all federal, state and local government web resources and services.