


Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
295 FXUS61 KGYX 220622 AFDGYX Area Forecast Discussion National Weather Service Gray ME 222 AM EDT Fri Aug 22 2025 .SYNOPSIS... High pressure will maintain fair weather over the region into the weekend. Long period swell from distant Hurricane Erin will continue to build into the weekend and will be slow to subside early next week. A slow moving cold front will bring increasing chances for showers late Sunday into Monday. Troughing will linger over the Northeast through the middle of next week. && .NEAR TERM /THROUGH TODAY/... Key Messages: * Swell has arrived from Hurricane Erin. Combined with increasing wave heights, this will create high surf and dangerous rip currents along the coast today through Saturday. Dry weather continues with sunny skies today. Some cirrus from Hurricane Erin in the open Atlantic may be observed early this morning, but this should pull offshore as the day progresses. Between incoming high pressure ridging and Erin, pressure gradient overhead will be enough for a northerly breeze this afternoon. Given daytime heating, this mixing will be enough to bring down some dry air aloft, causing lower RH values. Adjusted dewpoint temps down from NBM by mixing to 800mb. Warmer today with highs into the lower 80s, but still plenty comfortable given the lack of much humidity. Interior temps warming should bring a seabreeze inland through the afternoon. Should background northerly winds remain a factor, how far inland may be limited. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... Key Messages: * High surf and high rip current risk continues Saturday, but a slow decrease in wave heights is forecast. * Wave action, surge, and a high astronomical tide cycle will bring the threat for beach erosion, splash over, and minor coastal flooding during the Friday night high tide. See Tides/Coastal Flooding sections for more information. A few additional clouds tonight and warmer. Still expect low lying spots to radiate pretty well with lows into the upper 40s once again. Otherwise, lows generally fall into the mid to lower 50s. Upper level ridge crests Saturday with the low levels beginning gentle SW flow and moisture advection. Precip will hold off, but an increase in clouds will be noticeable vs. the second half of the week. Temperatures likely peak here for the week with highs pushing into the mid 80s. Winds at the surface will have shifted southerly, becoming breezy in the afternoon. This southerly flow will have a bit more moisture with it, with not as dry RH values vs. Friday. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... ...LT Update... Mid-level s/wv ridging will begin to exit to our east on Saturday night ahead of an area of low pressure that will be crossing over Quebec. Clouds will gradually increase overnight and a few showers are possible across the north and mountains overnight with low temperatures within a few degrees either side of 60. Clouds will continue to increase on Sunday with shower chances gradually sinking south through the day as closed low pressure over Quebec sends a sfc cold front eastward. High temperatures will be into the 70s to lower 80s. A weak secondary area of low pressure is then progged to form along this front Sunday night into Monday, bringing our best potential for more widespread rainfall of the entire forecast period. Rain chances will then diminish Monday night into Tuesday but a few wrap-around showers are possible across the higher terrain and far north. Trofing then looks to persist through much of the remainder of the week with temperatures a little below avg and little in the way of additional rain chances. Previous Discussion... High pressure moves east Sunday as a trough deepens over the Great Lakes. This trough will slowly migrate east through the middle of next week and will send a frontal system across New England late Sunday through Monday. Cyclonic flow aloft will linger through the end of the period that will maintain low chances for showers with a cooling trend into next Wednesday. Sunday looks to remain mostly dry as a frontal system over the Great Lakes will be slow to move east. Southerly winds will become breezy Sunday, especially along the coast towards central Maine where gusts will approach 30 mph. Clouds and rainfall chances will increase west to east late Sunday with showers likely Sunday night through Monday. Ensembles continue to suggest much of the area will see measurable rainfall, while even the high end QPF members suggest this rainfall will do little to reduce the precipitation deficits that have been building over the past two month. Th trough axis will remain west of New England Tuesday with embedded waves bringing continued chances of showers. The trough will move overhead Wednesday for a cooling and drying trend. The latest round of NWP guidance suggest the trough will linger through the end of next week with additional waves rotating through the trough that could bring additional chances for showers. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... Short Term...Mainly VFR through tonight with some valley fog at HIE/LEB and through southern ME. Northerly winds pick up today, but will see a wind shift for coastal terminals where sea breeze comes through this afternoon. Southerly winds for Saturday, with some gusts 15 to 20 kt. Long Term...Mainly VFR into Sunday. A cold front crosses late Sunday and Monday with lowering cigs and showers bringing the potential for at least MVFR conditions. Strong southerly flow ahead of the front will also bring the threat of wind shear Sunday into Monday morning. && .MARINE... Short Term...Large, long-period swells from Hurricane Erin continue to build over the waters and bays. There may also be a period of north to northeast winds gusting to around 25 kt into this morning, mainly over the outer waters. SCA conditions persist through Saturday as wave heights are slow to decrease behind Erin`s departure. Long Term...Long period swell from Erin will be on the downward trend as seas will continue to run above 5 feet into Sunday. Southerly flow ahead of a cold front will ramp up Sunday with wind gusts likely continuing SCA conditions into Sunday night. Winds and seas drop below SCA thresholds Monday. && .TIDES/COASTAL FLOODING... High astronomical tides and up to 2 feet of storm surge may produce minor coastal flooding and splash-over during the late evening high tide tonight, and a Coastal Flood Advisory has been issued. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...High Surf Advisory from 6 AM this morning to 8 PM EDT Saturday for MEZ023>028. Coastal Flood Advisory from 10 PM this evening to 1 AM EDT Saturday for MEZ023>028. NH...High Surf Advisory from 6 AM this morning to 8 PM EDT Saturday for NHZ014. Coastal Flood Advisory from 10 PM this evening to 1 AM EDT Saturday for NHZ014. MARINE...Small Craft Advisory until 8 PM EDT Saturday for ANZ150>152- 154. Small Craft Advisory until 8 PM EDT Saturday for ANZ153. && $$ NEAR TERM...Cornwell SHORT TERM...Cornwell LONG TERM...Schroeter/Tubbs TIDES/COASTAL FLOODING...Combs