093 FXUS61 KGYX 111247 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 847 AM EDT Thu Oct 11 2018 .SYNOPSIS... Low pressure will approach from the west today as a cold front sags to our south and provides much cooler weather. Locally heavy rainfall will be possible today. Cool weather then continues Friday into the weekend with wet weather possible Saturday. Another cold front looks to arrive early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Update...Minor changes to reflect latest observational trends. Not expecting a huge push with the backdoor cold front N today...where hi-res guidance suggest it remains stuck S of ASH. At this point I expect some thunder possible this afternoon...but mostly elevated. If the warm front can struggle N...a few surface or near-surface based storms are possible. Previous discussion...The main forecast challenge today will be the QPF forecast and any flood potential. A backdoor cold front has made its way southward overnight and is now located across southernmost NH which then snakes nwwd near the CT river. This front has put an end to our bonus summer days and has also allowed for fog and drizzle. Even though the boundary layer will be chilly today for the vast majority of the forecast area, anomalously high PWATS will exist above the cool low levels. This will set the stage for a period or two of heavy rain today as a short wave trough moves in from the west. As far as the QPF goes for today, have taken a blend of several models with most credence given to the 00z deterministic ECMWF which is in good agreement with its latest ensemble QPF output. The HRRR-TLE is in line with the EC as well. This makes sense as the heaviest rainfall should be near the baroclinic zone just above the boundary layer which is a little ways north of the SFC front. There is a possibility that the axis of heaviest rainfall could be further south if the baroclinic zone sags further south than expected. At this time we are looking at 1 to 2 inches of rain (highest amounts the aforementioned zone roughly from Sullivan County and southern Grafton County in NH eastward to the mid coast of ME). Will also have to watch southeasternmost NH as well late this afternoon as heaviest rainfall may working northeastward from MA. This rainfall shouldn't be enough to cause widespread flooding issues. However, will have to watch for minor flooding of roads and low spots, especially where leaves have clogged storm drains. There is an outside chance of isolated flash flooding if more robust elevated convection develops and trains. A rumble of thunder or two will be possible across southern and western zones. As far as temperatures go, kept close to the mesoscale models today as they'll have the best handle of the low level cold air damming. Overall, not a nice day for most. However, There is a shot across southernmost NH near the MA border (as well as CT river) than temps may average in the 70s today if the low level cold surge is too weak to push the SFC front much further south and west. It could also waver around allowing for rather large swings in temperatures at any given hour. Not a whole lot of confidence in high temps today in the MHT-ASH-KLEB corridor and south. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... The short wave trough moves through by early evening ending the threat of heavy rain. However, we will probably hold onto clouds through the night into Friday as the remnants of Michael fly by well to our south. Either way, Friday will be a nicer day than today by far, albeit cool and breezy. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... An overall pattern shift begins at the end of the week with long wave troughing and colder air aloft moving into place across eastern North America. The remains of Hurricane Michael will pass well south of the area on Friday night ushered quickly to the east by the arrival of a cold front moving in from the west. On Saturday morning there may be a few snowflakes in the mountains as we welcome the 540m line at 500mb back into the region for the Fall. With the colder temperatures to the north and the best chances for precipitation in the south along the temperature gradient the chance for snow will be limited to a few flakes at higher elevations. During the day temperatures will climb back up into the upper 40s to 50s. Saturday night temperatures will fall to near freezing all the way to the coast likely ending the growing season for much of the area. High pressure moves into the area providing a bit of moderation as temperatures return to the 60s on Sunday. The next system moves out of the middle of the country early next week. This strong wave looks to bring widespread precipitation to the region on Tuesday. There are two features we need to track for next week. Both a southern stream wave developing along the temperature gradient and moving south of the benchmark and a northern stream short wave diving south through the great lakes from Alberta. A bit of spread amongst the guidance on the timing of these two features which leave the potential for precipitation spread out amongst the middle of next week. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... Short Term /through Friday/...Mainly IFR conditions in low clouds, fog, and rain expected today. Rain will likely be heavy at times with a couple of thunderstorms possible. Winds will generally be light and northeasterly. Some improvement is foreseen later tonight as a low pressure system moves away to the east. Long Term...Generally VFR conditions through out the extended period. An approaching low pressure system near the middle of next week will bring some MVFR in showers. Brief cloudiness and SHSN are possible early Saturday morning for KHIE. && .MARINE... Short Term /through Friday/...Marginal SCA conditions to diminish today. The remnants of Michael will move well to the south of the waters Friday but may cause a period of SCA conditions, especially over southern waters. Long Term... Brief increase in swell on Friday night and Saturday morning as former hurricane passes to the south of the waters. At the same time cold air advection will bring winds to around 25kts and a small craft advisory will likely be needed. Conditions will moderate for the end of the weekend as high pressure builds in. && .TIDES/COASTAL FLOODING... Will go with a coastal flood statement from Portland on south to the Seacoast today as high astronomical tides and a north flow may allow for around half foot tidal departures today. This may result in some splashover around the time of early afternoon high tide. The former hurricane Michael will undergo extra tropical transition well south of out waters and pass east of us on Friday night and Saturday. Will need to keep an eye out for any longer period swell reaching our coast during this time as it may help to increase water levels to near Coastal Flood Advisory stage in combination with higher astronomical tides. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 5 PM EDT this afternoon for ANZ150>152. && $$ NEAR TERM...Legro