000 FXUS61 KBTV 050513 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 1213 AM EST Sun Feb 5 2023 .SYNOPSIS... Bitterly cold conditions this afternoon and evening will give way to a warming trend on Sunday as surface high pressure shifts east of New England. The next chance of precipitation, which should fall mainly as snow, arrives Sunday night with a weak cold frontal passage. More precipitation, this time mainly rain, is expected by mid week. && .NEAR TERM /THROUGH MONDAY/... As of 1212 AM EST Sunday...Temperatures continue to rise slowly but surely tonight with warm air advection riding winds from the south and southwest. Blended in some HRRR to both hourly temperatures and dew points, as our forecast was trending a bit too high on dews for observations, and the HRRR seemed to have the best idea on T and Td for the next several hours. Lowered some of the winds ever so slightly, as conditions are a bit calmer than expected under the ridge. Skies are now overcast for most locations across the forecast area, but this could fluctuate as lapse rates steepen throughout the day tomorrow and mixing occurs. Some light snow showers or flurries are possible across northern New York and potentially into Vermont tonight with the passage of a warm front, included slight PoPs for that in this update. Previous discussion below: Previous discussion...Southwest flow will increase this evening on the backside of the ridge and ahead of weak low pressure lifting up west of the St Lawrence Valley. This will allow a weak warm front to cross our area overnight, so the gradual warming trend will continue tonight right into Sunday. Areas east of the Greens will likely cool down a few degrees after sunset since they're the furthest removed from the warm front, but even those areas should see climbing temperatures after midnight. Therefore, lows will mainly occur early in the overnight period, ranging from 5 to 10 below in the Northeast Kingdom to around 10 above in the southern St Lawrence Valley. A few light snow showers can't be ruled out as the warm front lifts through, but the vast majority of the region will remain dry through Sunday morning. South winds increase through the morning as well, especially in the Champlain Valley owing to channeling, and temperatures will warm into the lower to mid 30s areawide in response. The weak parent low will slowly move by to our north late Sunday into Sunday night, and precipitation chances will increase as its associated cold front approaches from the west. The precipitation should start as rain as it moves into the St Lawrence Valley late in the afternoon, but the loss of daytime heating along with evaporational cooling should allow the bulk of the precipitation to fall as snow as the front gradually shifts east overnight. The snow will focus along the western slopes of the Adirondacks and the northern Greens, with an inch or two of accumulation expected. Elsewhere, snowfall will be less than an inch, with much of the Champlain Valley and central and southern VT to remain dry. Overnight lows will be in the mid 20s to around 30. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... As of 315 PM EST Saturday...Snow showers linger Monday morning across the Adirondacks and northeast Vermont associated with the aforementioned upper trough passage, but will quickly end by midday as high pressure builds eastward from the Great Lakes over the Northeast. Northerly winds on the front-side of the high will provide a non-diurnal temp trend with morning temperatures in the mid 20s west to mid 30s east gradually falling through the afternoon to the teens and 20s by the evening. Under the center of the surface and upper level ridge axis, lows Monday night will tail off into the single digits and teens above zero under partly cloudy skies. After a brief break of high pressure Monday night into Tuesday morning, active weather returns again heading into Tuesday afternoon/night as another lows looks to pass north/northwest of the region. Boundary layers temps ahead of the system will be warmer than the previous one with widespread mid/upper 30s and some 40s Tuesday afternoon, offering a valley rain and mountain snow mix Tuesday evening/night with the best chances for accumulating snow being across eastern Vermont where light accumulations are possible. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 315 PM EST Saturday...An impactful period of weather remains ahead for the middle to end of the work week and into the weekend with a very convoluted upper level pattern evolving. Driest period will be Wednesday and Wednesday night with high pressure briefly building back into the region, but by Thursday morning the first in a series of potent shortwaves embedded in a broad longwave trough digging into the central US will advance through the Great Lakes and northwest of the forecast area Thursday afternoon. Strong warm advection associated with a southwesterly 50-60kt 850mb jet will support temperatures once again rising above freezing with rain as the dominate ptype through Thursday night outside of the highest elevations where snow is likely. There also are indications of a brief period of a wintry mix of sleet or freezing rain as well at the onset, but given the poor resolution of guidance out this far have kept the ptype rain/snow for now. As this system exits the region Friday, attention will turn to the next 2 shortwaves over the Great Lakes and southern states and if/when they phase moving into the Friday night Saturday period. Too early to tell what will evolve, but there is some agreement among deterministic and ensemble guidance that the North Country will be impacted somehow. Whether it's more rain, mixed precipitation, or perhaps a significant snow storm remains to be seen, but it's something to watch closely heading into midweek. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Through 06Z Sunday...Main threat to aviators will be LLWS with a low level jet moving over the region. The shear layer should be around 2000ft out of the southwest around 40kts. SFC winds will be light and south for most terminals except MSS which is keeping a NE wind due to channeled flow down the St Lawrence Valley. South winds increase after 14Z with gusts to 20kts; this may limit LLWS somewhat as speeds begin to phase, but expect some turbulence to remain. Otherwise, conditions will remain VFR through 20Z with CIGs lowering west to east 20-06Z as a cold front moves into the North County. Outlook... Monday: Mainly VFR, with local IFR possible. Slight chance SHSN. Monday Night: VFR. NO SIG WX. Tuesday: VFR. Windy with gusts to 30 kt. Likely SHRA, Slight chance SHSN. Tuesday Night: Mainly MVFR, with local IFR possible. Likely SHRA, Slight chance SHSN. Wednesday: Mainly VFR, with areas MVFR possible. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: Mainly VFR, with local MVFR possible. Chance SHRA, Chance SHSN. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Hastings NEAR TERM...Hastings/Neiles SHORT TERM...Lahiff/Storm LONG TERM...Lahiff AVIATION...Neiles