000 FXUS61 KGYX 161911 AFDGYX Area Forecast Discussion National Weather Service Gray ME 311 PM EDT Sat Oct 16 2021 .SYNOPSIS... A strong cold front will will cross through the area this evening into Sunday morning bringing periods of rain, gusty winds, and a few rumbles of thunder. Cooler conditions will then arrive for the beginning of next week with daytime showers under northwest flow. High pressure and gradually moderating temperatures are then expected for the middle of the week before another disturbance arrives by next weekend. && .NEAR TERM /THROUGH TONIGHT/... At 3pm a cold front is crossing the Champlain valley and will move across New Hampshire and western Maine this evening. Ahead of the front, southerly flow has pushed temperatures into the 70s across the southern portion of the region, with dewpoints into the lower to mid 60s. This summer like airmass extends through much of NH where partial sunshine has broken out. Across Maine the 60s dewpoints push as far north and east as Bangor while the south flow has kept onshore flow and low clouds keeping temperatures in the 60s as well. It will be a race against the setting sun this afternoon to see how far the cold front can advance before it looses the warmth and instability to support surface based convection. For the moment, mesoanalysis would support thunder extending into western New Hampshire in early evening. Morning sounding from KGYX showed relatively steep lapse rates just below the freezing mark so some small hail is possible. Gusty winds remain the largest threat, with forecast soundings showing as much as 40-50 kts of wind just off the surface. The significant shear continues to support the potential for embedded QLCS tornadoes, and will need to be vigilant for any quick spin ups as it crosses the CT river. Expect the marine layer to take hold to the east, with convection becoming elevated later in the night as the front rolls through Maine. Have maintained a mention of thunder through midnight but expect the severe threat to rapidly decrease in the few hours after sunset. With the very humid airmass have also kept patchy fog in the area for most of the night. With the low level flow oriented mostly parallel to the front, there is some chance for training precipitation however the forward progress of the front makes for less of a concern for any flooding. Have used the RFC forecast for QPF, with a generalized widespread 0.5-1", however expect there will be several small areas which may see up to 2-3" if the heaviest cells end up in the same place. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... With the front crossing out the region early Sunday morning, westerly flow will develop. This will bring a steadily drying airmass throughout the day. Clearing skies will allow temperatures to climb into the mid 60s, more seasonable. Overnight the dewpoints in the 40s will keep temperatures from dropping too far and a bit of patchy fog is possible in the river valleys. && .LONG TERM /MONDAY THROUGH SATURDAY/... The inevitable pattern change that we have been awaiting will arrive on Monday with afternoon high temperatures in the mid to upper 50s, except lower 50s in the mountains. These temperatures remain nearly at or slightly above normal temperatures for this time of the year. This slightly cooler temperatures will be generated by an upper level low pressure system over northern New England. A cyclonic flow and cold pool aloft will allow for Cu to build during the day and scattered showers to develop in an area of steep low level lapse rates and upslope west to northwesterly flow across the mountains. Downsloping conditions may prevent any precipitation from reaching the coastline. Monday night will be a night with ample mixing and considerable in the clouds across the northern 2/3 portions of the forecast area. Despite this, expect temperatures to fall into the upper 30s in these areas by Tuesday morning. This upper level low will be slow to move out of the region on Tuesday, bringing a repeat process to the region with plenty of clouds. H8 temperatures around -4C will yield temperatures in the 40s across the northern mountains and 50s in the south. As the mid and upper level low shift to the east and winds align, expect westerly winds to become quite gusty during the afternoon. 12Z operational guidance and ensemble solutions remain in relatively good agreement gradually raising heights across the Northeast on Wednesday. This will allow for drier conditions along with warmer temperatures. This will continue into Thursday as warm air continues to filter into the region and low pressure remains over southern Canada. By Friday and into early next weekend, a strong cold front will cross the region with its associated trough aloft. H8 temperatures will be falling with widespread readings near -8C by Saturday night. However, there are still significant variability amongst the ensemble solutions in terms of daily high and low temperatures. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Short Term... Scattered cumulus across New Hampshire has the entire state holing in VFR for the moment. Meanwhile, in Maine the midcoast can't seem to loose the low clouds and IFR to LIFR is expected to hold through tomorrow morning. A cold front will cross the region this evening. With a very strong low level jet,some LLWS is possible although for the most part those winds are mixing down enough to keep mention of it out of the TAFs. Expect a return to IFR across all of coastal Maine overnight, with some thunder possible as the front moves through. Winds will finally turn west with clearing skies and VFR returning for the day on Sunday. Long Term...A westerly flow will prevail through the beginning of next week and will be gusty at times, especially during the afternoon and early evening hours. VFR conditions will prevail across most terminals but scattered SHRA will result in MVFR/brief IFR conditions at times, especially across northern terminals such as KHIE Monday into Tuesday. && .MARINE... Short Term...Strong southerly flow ahead of a cold front will keep gusts to 30kts in the waters this evening and a SCA remains in effect. Behind the front winds will turn westerly decreasing to below 25kts by morning, and holding light west to northwesterly through Sunday. Long Term...South winds becoming west gusting up to 25 to 30 kts tonight into Monday. West to northwest winds on Monday night through Tuesday night will continue to gust to near 25 kt. Winds and seas will then diminish by Thursday as high pressure gradually builds over the waters. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 8 AM EDT Sunday for ANZ150>154. && NEAR/SHORT TERM...Cannon LONG TERM...Curtis