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 191537 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1137 AM EDT Wed Oct 19 2016 .SYNOPSIS... Expect a warm day today with clearing skies as high pressure builds in from the west. This area of high pressure moves into the maritimes on Thursday as low pressure developing over the Ohio Valley tracks northeast toward northern New England by Friday. This will bring a period of wet weather from late Thursday into Saturday. A cold front pushes through from the west on Saturday bringing colder weather but a return to dry conditions for the latter part of the weekend into early next week. && .NEAR TERM /TODAY/... 1130AM UPDATE... Temperatures have soared this morning as the heating we have had so far has allowed the atmosphere to mix up to the inversion noted in the earlier update. This has also caused wind gusts to be a little higher than expected, as 850MB winds of 30KT should be able to mix partially down to the surface given the good mixing going on today. Highest temperatures in these offshore flow situations tend to be right along the coast, so if you`re looking for an 80 degree temperature today the best chance would be in coastal towns or in southern New Hampshire where the downsloping winds have the greatest effect. 845AM UPDATE... Morning upper air observation shows a steep inversion with a very warm layer just above the surface. This should allow temperatures to pop up quickly this morning, likely hitting the mid 70s fairly quickly before slowing their upward trajectory. Have updated the forecast to show a quick warming and increase high temperatures a few degrees, now showing a few locations hitting 80. Also zeroed out the precipitation chances as no more rain is expected. No other changes were made. 545AM UPDATE... Cold front along with any surface convergence along the boundary was almost offshore around 6 am this morning. QPF amounts have been very light. There is still some light rain mainly over the Augusta/Wiscasset/Rockland environs. Adjusted PoPs based on radar and current timing. Also adjusted temperatures and dew point temperatures based on latest mesoanalysis. ORIGINAL DISCUSSION... A cold front was moving through central New England this morning, albeit slowly. A warm front snaked through portions of Maine and New Hampshire with readings in the 70s noted over northern MA. This warmth will continue to spread this morning and have kept the non-nocturnal curve in place. To the northeast a cooler wedge of air including dense fog and drizzle was eroding from the southwest as mixing increases ahead of the warm front. Underneath the inversion temperatures are in the 50s and 60s and will continue to slowly tick upwards overnight. Rain showers will come to an end this morning as the frontal boundaries are swept offshore. The coastal plain will clear out quickly with sunny skies expected. Over the higher terrain some upslope clouds will linger. Temperatures will vary from the lower 60s north to near 80s near Nashua and Manchester where the downslope component of the winds will be enhanced. && .SHORT TERM /TONIGHT AND THURSDAY/... Despite clear skies tonight we will not fully realize our radiational cooling potential everywhere. Where winds do decrease enough, temperatures will drop into the 30s. The mid to upper 40s will be much more likely across the forecast area however. Cloud cover returns Thursday as another warm front lifts into the northeastern states. This will spread rain cross the region and will likely bring some measurable precipitation to many areas. Highs will be slightly cooler due with readings generally in the upper 50s to lower 60s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A progressive digging upper trough will move across the Ohio Valley and Great Lakes region will allow showers to become widespread Thursday night. The upper trough will continue to develop over the eastern Great Lakes Friday becoming vertically stacked and spawning surface cyclogenesis across the St Lawrence and then a redevelopment along the New England coast late Friday. A broad area of rain is expected for Friday. The upper trough will continue to develop as it becomes negatively tilted and then becomes a closed low by Friday night. As the system develops, models are indicating a strong southeast flow will develop to its east and will likely pick up some tropical moisture from a system off the southeast coast of the U.S. This may bring some soaking rains to the area late Friday into early Saturday. Modes in some disagreement with the EURO being the wettest model. Models indicate the closed upper low is expected to move slowly north and east into the maritimes Saturday and Sunday allowing some lingering showers mainly in the mountains due to the unstable cyclonic flow. In southern areas generally dry conditions expected for the weekend. Much cooler temperatures will arrive behind the system Saturday into early next week. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... Short Term...A mixed bag of VFR to LIFR conditions are prevailing this morning- mainly in ceilings that will last a few more hours until a cold front pushes offshore taking much of the moisture with it. All terminals will see VFR shortly after sunrise today, which will persist through Wed night. Somewhat gusty westerly winds are om tap for this afternoon. Long Term...Conditions become IFR Thursday night as an onshore flow persists in bringing in low level moisture. More substantial rainfall is possible on Friday and Friday night as low pressure moves through the area, likely keeping conditions IFR to lifr. A cold front pushes east through the area Saturday morning, allowing clearing conditions to VFR over southern areas while in the mountains and foothills MVFR conditions in scattered showers will persist through much of the weekend. && .MARINE... Short Term...SCA has been extended through noon for a few gusts to 25 kts as well as seas around 5-6 ft. After daybreak the higher seas will be confined from Cape Elizabeth eastward. We will near SCA conditions again on Thursday. Long Term...East to southeasterly wind flow ahead of low pressure moving through northern New England should stay near or below advisory levels, but the onshore nature of the wind will allow wave heights to build to over 5 FT. A cold front pushes east across the waters Saturday morning, with a west to northwesterly flow behind it which will likely gust above 25 KT at times. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM UPDATE...Kimble SHORT TERM...Hanes LONG TERM...Marine is the U.S. government's official web portal to all federal, state and local government web resources and services.