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 010031 AFDGYX Area Forecast Discussion National Weather Service Gray ME 831 PM EDT WED AUG 31 2016 .SYNOPSIS... A slow moving cold front will continue to sag south through New England tonight and will push offshore on Thursday. High pressure will gradually build in from the west Thursday night through Friday. High pressure will crest over the region early Saturday before shifting offshore. Although confidence is low... sub-tropical low pressure will move north along the east coast Saturday night and Sunday and may affect southern New England Sunday night into Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
830 PM Update...Forecast remains on track. Scattered showers and thunderstorms across Coos County NH will gradually work eastward and likely gradually weaken with the loss of diurnal heating as they move through the western ME mountains. 545 PM Update...Just a few minor adjustments to the forecast for this evening and overnight based on latest trends in radar and mesoscale model data. Showers and thunderstorms across northernmost VT and southern Quebec should move into Coos County NH and the western ME mountains over the next couple of hours. The activity will probably weaken from it/s present state but still expect some heavy downpours and occasional lightning strikes. Otherwise, further south, expect dry weather except for perhaps a spot shower. Previously... Current 500 mb trough approaching from the west showing a little disorganizations with weak waves rotating just south of the closed low over Quebec and anther wave lagging a bit zonally and crossing into PA/NY this afternoon. First wave to the north will pass thru late this afternoon and evening and is currently setting off sct convection in srn Quebec and along the intl border of NY. This will track thru the far nrn zones between 21z and 01z and will see a few sct SHRA and maybe a TSRA. Then later tonight, after mid night will see another threat for showers in the southern zones associated with the wave to the south. These are less likely to have any lightning. OVernight lows will range from the upper 50s in the mountains, where the front should cross before daybreak, and the mid 60s in the south, which will see a surge in low level moisture ahead of the front, producing some fog as well.
-- End Changed Discussion --
&& .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... As upper level wave flattens early Thu, the front will slow to a crawl as it hits srn NH and the coastal plain of ME, this will keep a fair amount of clouds around and linger the threat for SHRA/TSRA in these areas into at least early afternoon on Thu. The front should eventually move offshore with some clearing, from N to S, during the mid to late afternoon. Highs will range from the upper 70s to around 80 in the south to only around 70 in the north behind the front. Will also a reduced rip risk at least for Thursday. Thursday night will see better clearing, but low level moisture will linger closer to the coast. It will be cooler everywhere with lows near 50 in the north to around 60 on the coast. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... High pressure building in from the west on Friday will produce a mix of sun and clouds and seasonable temps across the region. High temps will range from the mid 60s to lower 70s north and in the lower to mid 70s south. High pressure will crest over the region Friday night. Clear skies and light winds will allow for good radiational cooling with lows ranging through the 40s north and lower to mid 50s south. High pressure will slide offshore on Saturday. Expect the majority of the day to feature abundant sunshine with highs generally ranging through the 70s from north to south. Forecast confidence drops off at this point as remains of TD 9 heads up the east coast. Still some differences in timing and track of this system with the new GFS hugging the east coast and weakening as it moves north to the vicinity of Long Island by Monday morning. After another nice day Sunday this would bring some light rain into southern zones late Sunday night into Monday. New ECMWF has been trending toward the GFS solution for the past several days and this trend continues this afternoon... although the ECMWF track remains just offshore over the warmer waters north of Hatteras on its trip northward maintaining a slightly lower central pressure. This solution would also bring clouds and a little light rain into coastal and southern interior zones on Monday. In any case...expect upper level ridging building in from the west on Tuesday to finally push this weakening system eastward. Expect both days to be sunny and warm with highs pushing well into the 80s by Wednesday. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Short Term...A period of IFR or lower is expected during the pre- dawn at KHIE/KLEB/KAUG. Could see MVFR fog at other terminals, but confidence not high enough for TAF inclusion. VFR is expected Thu into Thu night, with the exception of valley fog. Long Term...VFR Friday through Sunday. Some MVFR/IFR ceilings possible in coastal and southern interior zones on Monday. && .MARINE... Short Term...Swell heights are dropping off a bit tonight and Thursday, and winds will remain below SCA levels as well. Long Term...SCA`s may be needed late Sunday into Monday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.