469 FXUS61 KBTV 171131 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 631 AM EST Tue Nov 17 2020 .SYNOPSIS... A cold front will cross the area today into this evening along with variable clouds and scattered flurries, mainly across higher terrain. Expect a chilly day on Wednesday behind the front, after which temperatures moderate considerably by Thursday into next weekend as south winds return. The next chance of significant precipitation occurs by Sunday night into Monday. && .NEAR TERM /THROUGH WEDNESDAY/... As of 630 AM EST Tuesday...The forecast remains largely in good shape as of 600 am. I did put in a 1-3 hour window of higher shower chances through late morning across central/northern counties along a pre-frontal convergence line dropping southward this morning, evident as a line of snow showers across northeastern NY into the northern Champlain Valley and portions of nc/ne VT. Within this band, brief visibility restrictions to below 2 miles are likely, though with sfc temperatures aoa freezing little to no impacts are expected. Otherwise, just some minor cloud coverage adjustments were made to line up with current observational trends. Have a great day! Prior discussion... Variable clouds will be the rule over the next 36 hours as a cold front crosses the region. Deeper moisture is lacking with with this feature, so only low to slight chance PoPs (10-30%) will be offered today with any minor accumulations occurring in elevated terrain (< 1 inch). High temperatures to hold steady this morning (30s to around 40), then slowly fall this afternoon as flow veers northwesterly over time behind the boundary. By tonight the front clears well south and east of the area. However, models generally concur that ample moisture in the lower to mid levels will become trapped beneath a building synoptic inversion near 850 hPa. As such, while the broad valleys will likely trend partly cloudy, higher terrain will likely hold on to ample cloud cover with some scattered flurry activity here and there owing to the above reasoning and some lightly forced orographic effects. This appears reasonable given this is a common occurrence during post- frontal northwest flow regimes and current upstream clouds across southern Canada. Given the expected cloud cover I ended up raising minimum temperatures by 1-3 degrees in our colder northern mountain locales. Then variable clouds/mtn flurries thin/end by Wednesday morning, with partly to mostly sunny skies expected by afternoon as high pressure builds eastward. This will be the coldest day of the week with mean 925 hPa temps hovering only around -10C supporting highs only in the 20s to locally around 30. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/... As of 250 AM EST Tuesday...Last chilly night in store for the short/extended period on Wednesday. Temperatures should drop pretty rabidly for the 1st half of the night before clouds and southerly winds increase after 06z. Hollows across the Adirondacks and eastern VT will see the coldest readings in the upper single digits/low teens, with mid teens to around 20 elsewhere. As warm front begins to push northward expect cloudy skies throughout the day Thursday. Temperatures will be near to slightly below normal from west to east, with warmest readings across the St Lawrence Valley (mid/upper 40s) and coolest readings (mid/upper 30s) for far eastern VT/Northeast Kingdom. Despite fairly normal readings, southerly winds will increase during the day Thursday around 10-15 mph (20-25 mph over Lake Champlain) which will make for chillier conditions. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 250 AM EST Tuesday...Overall, relatively quiet period of weather through the weekend. Zonal flow aloft will continue to bring several impulses across the North Country, however expect only an increase in cloudiness as available moisture is lacking. Surface boundary begins to sink south of southern Quebec Saturday. A few sprinkles may be possible with this boundary, but expect largely dry conditions. Near to slightly above seasonable temperatures in the mid 40s/low 50s are expected Friday - Sunday. Our next system begins to approach from the west Sunday, with breezy southerly winds increasing throughout the day. Surface cold front moves through Monday morning/afternoon. P-type is looking like rain at this point outside the highest terrain with a chance for some scattered snow showers late Monday night as surface front pulls away to the east. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Through 12Z Wednesday...Mainly VFR expected over the next 24 hours as cold front crosses the region this afternoon. BKN/OVC cigs generally in the 035-070 AGL range expected through through the period, with some occnl partial breaks at favored terminals of KMSS and KPBG. Scattered flurries likely through much of the forecast period in higher elevations/KSLK with a brief 1-3 hour window of MVFR/brief IFR -shsn possible at KSLK/KPBG/KBTV/KMPV through late morning/early afternoon as front passes. Winds generally west to southwest 5-9 kts through 16Z, trending west to northwesterly 6-12 kts thereafter behind the front. Outlook... Wednesday: VFR. Chance SHSN. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Saturday: Mainly MVFR, with areas VFR possible. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...JMG NEAR TERM...JMG SHORT TERM...LaRocca LONG TERM...LaRocca AVIATION...JMG