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 280958 AFDGYX Area Forecast Discussion National Weather Service Gray ME 558 AM EDT THU JUL 28 2016 .SYNOPSIS... A weak frontal boundary will drop south out of Canada and into northern New England Today, bringing a chance for showers and thunderstorms as it does so. The front slowly slips offshore on Friday as low pressure track easts along the front offshore of Cape Cod. This will bring another chance of showers Friday into Friday night. Cooler, more seasonable temperatures return for the weekend with dry conditions Saturday and another chance for showers on Sunday into Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Update... Have updated the grids based on current conditions and mesoscale models. A few light showers north of the border will gradually build south in association with the approaching cold front today. By afternoon, convection will enter the mix as showers and scattered thunderstorms will be ongoing over the northern mountains. A thin band of CAPE values AOA 1000 J/kg will be situated over central areas at this time. This precipitation will then reach portions of southern Maine and New Hampshire by late afternoon where onshore winds along coastal areas may limit the convection. In the meantime, very little changes to the grids with this forecast package update. Prev Disc... A slow moving cold front will cross the forecast area from northwest to southeast during the day today. Scattered showers and possibly a thunderstorm will be ongoing over the northern mountain regions early this morning. Instability will increase as the system settles south this afternoon, triggering more showers and thunderstorms. Dynamics appear to be insufficient for severe weather today across Maine and New Hampshire. It will continue to be hot, especially over southern interior sections which will exceed 90 degrees this afternoon. A few sections over southern interior New Hampshire could hit 95 degrees. This heat has been highlighted in some of our products. Onshore winds will keep conditions cooler along the coastline. However, this onshore component will increase dew point values into the mid 60s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... The cold front will slip off the coastline this evening and with the loss of daytime heating, showers and thunderstorms will gradually end over southern areas. This front will become quasi- stationary once it reaches the southern New England coastline. Patchy fog will once again redevelop over a more widespread region than the last few nights. Models are coming into better consensus as a coastal system moves northeast along the front and across the southern New England coastline Friday. Mesoscale models continue to indicate an area of briefly heavy rainfall will cross southern sections during the day, bringing temporary relief to the drought conditions. Further to the north in northern New Hampshire and Central Maine, the precipitation will be much lighter. The cloud cover and precipitation will keep temperatures confined to the 70s on Friday. However modestly high dew points will make it feel more humid once again. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... The models remain in general agreement on the long wave pattern through early next week. A weak broad trough will offer some relief from the heat early in the period as a slow-moving cold front gradually pushes well south of the area. A weak low will travel northeast along this slow-moving boundary late Friday before the front finally clears the coast early Saturday. High pressure and drier air follows for Saturday into Sunday. By late Sunday the next shortwave and week surface reflection is approaching from the south and west marked by increasing clouds and a chance of showers. This system will linger on Monday with clouds and unsettled weather. By Tuesday...the upper trough retreats offshore with rising heights and a more westerly flow aloft opening the door to building heat and humidity for the remainder of the work week. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... Short Term...VFR conditions are expected early this morning, except for perhaps a few hours of patchy fog. VFR conditions then becoming MVFR in developing scattered showers and thunderstorms this afternoon and evening. After the showers end this evening...fog will form and be more widespread. Long Term... Fri night...sct MVFR IN -shra/-tsra. Sun night - Mon...Areas of MVFR IN shra/tsra. && .MARINE... Short Term...Conditions are expected to remain below small craft thresholds through Friday...however winds may gust to as high as 20 kts today out over the open waters. Long Term... Sat...winds and seas may briefly approach small craft outside the bays. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ JC/ES is the U.S. government's official web portal to all federal, state and local government web resources and services.