864 FXUS61 KBTV 061116 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 716 AM EDT Wed Oct 6 2021 .SYNOPSIS... Clouds and areas of fog this morning will slowly dissipate this morning with mostly sunny skies developing this afternoon. Temperatures will continue to be above normal with highs in the mid 60s to lower 70s. A prolonged period of mainly dry conditions with above normal temperatures will prevail through the week and into the upcoming weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 700 AM EDT Wednesday...Several minor updates needed this morning, which included lowering temps acrs the SLV into the lower 40s based on sfc obs from MSS to OGS to PTD, while fine tuning the clouds/areas of patchy dense fog. Fog/br should lift btwn 14-15z this morning, as Whiteface summit cam is showing mostly clear skies with an undercast in the valleys. In addition, the Lidar plot from the NY State Mesonet at Tupper Lake indicates nicely how shallow our llvl moisture is this morning, mainly below 2000 ft. As sfc high pres builds directly overhead, clearing will occur btwn 14-16z today, with mostly sunny skies expected by this aftn. Rest of fcst remains unchanged. Previous Discussion Below: When will the low clouds and patchy fog dissipate continues to be the fcst challenge today. Nighttime microphysics imagery shows some clearing slowly developing near the International Border, while most of our fa remains socked in with low clouds and patchy fog. Utilizing the 1000 to 850mb ML RH>70% off the RAP, which is handling the crnt clouds the best, would suggest clearing skies develop btwn 15z-18z today, with the dacks and parts of central/southern VT the last areas to clear. In addition, NAM 3km and RAP sounding data, suggests moisture trapped below 2kft should mix out at BTV btwn 16z-17z today, so have utilized these tools to keep clouds in the grids this morning, but clearing by this aftn. Temps are starting off very warm today with values mainly in the upper 40s to mid/upper 50s, but clouds wl limit heating during the morning hours, however we should make up for lost time this aftn with sunshine and temps warming mid 60s to lower 70s under light winds. Tonight, 1027mb high pres directly overhead wl result in clear skies and light winds. Upstream satl imagery shows areas of fog has developed directly under this high pres system acrs southern Canada, so expect widespread fog/br on Thurs morning acrs our fa. Expect a large diurnal drop in temps, given the drier air/less clouds with values lowering 3 to 5 degrees below cross over values. Thurs with feature plenty of sunshine once the fog/low clouds burn off by mid-morning. Progged 925mb temps btwn 13-14c support highs upper 60s to lower/mid 70s most locations. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... As of 340 AM EDT Wednesday...On Thursday night, we will temporarily redevelop the nocturnal mid- level stratus clouds with some patchy fog where any breaks develop. Overnight lows will range from the mid 40s to lower 50s. The atmosphere will remain quite dry on Friday. 925 hPa temperatures of about 15 C suggest highs in the low to mid 70s will be likely. PoPs nil. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 340 AM EDT Wednesday...Friday night, a pronounced backdoor cold front will shift across the region with north winds becoming easterly. A narrow tongue of moisture ahead of the backdoor front and terrain induced convergence along the Greens could produce patchy drizzle in eastern Vermont into early Saturday. It seems the backdoor front will make it as far as the Adirondacks before the flow will shift south to southwesterly again as the upper ridge will give way to a weakening shortwave trough. Strong 1031 mb surface high will become established near Maine with tightening pressure gradients producing breezy 20 to 30 mph gusts in the afternoon, especially across channeled valleys. Light rain will develop across northern New York Saturday afternoon, and then how far this activity will progress east will depend somewhat on the strength of an offshore low along the Carolina Coastline. The farther north and the stronger it is, the more dry air will be advected into the North Country, but if it's farther south and weaker, then we will see some precipitation translate into Vermont. Either way, the amounts will be unsubstantial. We will briefly cool over the weekend, but remain above normal. The first half of the next week continues to look mostly dry. A pair of disjointed shortwaves will traverse near or just north of the North Country, and better synoptic scale forcing appears most likely to remain over the Great Lakes region and in Canada at this time with ridging continuing to dominate. This corresponds well with the relative minimum in total precipitation amongst ensemble members across New England. Temperatures will likely warm back to near 70. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... Through 12Z Thursday...VLIFR at MPV/SLK/MSS in dense fog with IFR at RUT/EFK, while MVFR CIGS prevail at BTV/PBG. Expecting VLIFR/IFR conditions to improve to MVFR by 14z and all sites should experience VFR conditions by 15z today. Winds will remain light from the north/northwest under 5 knts. Surface high pres directly overhead tonight will result in widespread fog/br again tonight, which should develop btwn 03-05z, with VLIFR conditions likely at MPV/SLK again and IFR at MSS/EFK/BTV/PBG and RUT. Outlook... Thursday: VFR. NO SIG WX. Thursday Night: VFR. Patchy BR. Friday: VFR. Patchy BR. Friday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Saturday: Mainly VFR, with local MVFR possible. Chance SHRA. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Slight chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Taber NEAR TERM...Taber SHORT TERM...Haynes LONG TERM...Haynes AVIATION...Taber