260 FXUS61 KBUF 070835 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 335 AM EST Tue Dec 7 2021 .SYNOPSIS... Colder air pouring into the region will prompt accumulating lake snows east of both lakes through today while winds will remain at elevated levels. Weak low pressure will encourage some nuisance snow showers throughout the region for Wednesday. Warmer weather will arrive Friday into Saturday. && .NEAR TERM /THROUGH TONIGHT/... Model soundings suggesting a fairly well aligned 280-290 flow today will continue to focus lake effect snows at the Southern Tier off Lake Erie and from northern portions of Wayne/Cayuga counties into Oswego county/Srn Tug off Lake Ontario. Several more inches of snow will fall for the Lake Ontario counties with perhaps another two inches across the Southern Tier. Otherwise, it will be a chilly and brisk day today. Temperatures holding in the upper 20s to lower 30s. West winds gusting to 25-30 mph will keep wind chill values in the teens. The lake snows will persists tonight, while taking a gradual northward shift as winds back more southwesterly. A lack of moisture in the dendritic growth zone should limit snowfall amounts to the 1-3 inch range. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Upper level trough axis will pivot across the central and lower Great Lakes Wednesday and Wednesday night, supporting a weak surface wave of low pressure. This will produce some light scattered snow showers across western and northcentral New York. In the wake of the system Wednesday night, cold northerly flow will set up across the region. This may produce some lake effect snow showers south of Lake Ontario producing up to a half inch at best. That being said, a drier air mass will be entering the region late Wednesday night which could limit the lake effect potential. Despite this, cloudy skies will prevail across the regions south of Lake Ontario. Thursday, upper level ridge axis and corresponding surface high pressure will slide east across the area. Initially, this will result in the last of the lake effect showers south of Lake Ontario to peter out by mid morning. Then, the remainder of the day will become rather quiet. Along with the ridging, southerly winds will promote a warmer air mass to begin to advect into the region, marking the start of period of warming. Meanwhile Thursday, far to the west of New York State, the next upper level low over the Saskatchewan province will extend its trough across the Central Plains and allow a shortwave trough to round its base. This shortwave will support a warm front and cross the region from southwest to northeast Thursday night. At first, temperatures will be at its minimums for the night in the early evening, then as the front passes a gradual warming trend will set up overnight. Additionally, this will support all snow showers early in the night, before switching to a rain/snow mix across the lower terrain. && .LONG TERM /FRIDAY THROUGH MONDAY/... Friday still appears as though it should be a mainly dry day as a warm front moves northeast of the area, while another warm front moves into the Ohio Valley stemming from a developing storm over the central Plains. Our attention will then turn to the next system to impact our area. Models in rather good agreement 4 to 5 days out on a Colorado Low deepening and taking a climatologically favored track to the northeast, cutting somewhere through the western Great Lakes Friday night into Saturday. This will allow a deep southwesterly flow (out of the GOMEX) to develop later Friday into the first part of the weekend. Deep moisture and strong forcing out ahead of the aforementioned warm front extending east from the system will spread rain showers across the lower Great Lakes region Friday night into Saturday. This will also lead to a non-diurnal trend with warming temperatures Friday night, peaking with a very warm day on Saturday as highs top out in the 50s across the majority of the area. As the system rapidly pulls northeast into west-central Quebec Saturday night, its' associated cold front will plow across the lower Great Lakes with rain changing over to snow before the moisture is stripped away in the wake of the mid level trough passage on Sunday. Expect just some leftover scattered rain and snow showers for the second half of the weekend. The other aspect of this system will be the wind potential, as this is also a climatologically favored scenario for strong winds across our forecast area with a strong deepening low moving to the northwest of western and northcentral NY. At the least, a strong pressure gradient will develop between the deepening low to the northwest and strong high pressure over the western Atlantic all but guaranteeing at least breezy to gusty conditions during this timeframe. The big question will be if strong to damaging winds will be realized. One area there is currently some discrepancy in the models is the position and strength of the strong low level jet just off the deck. Winds aloft have a difficult time mixing down on the warm advection side of a system (exception being localized downslope winds), so if the strong winds just off the deck move out before cold air advection commences (i.e. cold FROPA), the opportunity for strong to damaging winds will not be reached. One other note; any changes in the forecast strength of the low and/or deviation in the track will also have impacts on wind potential as well. This system will need to be watched, stay tuned. Models continue in fairly good agreement that high pressure then builds in toward the tail end of the period, with dry conditions to start the new work week. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... Mainly VFR conditions expected today. Localized MVFR/IFR in lake effect clouds/snow showers will continue E and ESE (including KJHW) of both Lakes. Winds gusts should peak no higher than 25 knots across the area through the day, then diminish late this afternoon. Tonight, VFR conditions will continue. Local MVFR/IFR in lake clouds and lake snows east of the lakes, possibly reaching KBUF and KART after 03z. Outlook... Wednesday...MVFR in light snow showers. Thursday and Friday...VFR. Friday night and Saturday...MVFR in rain. Chance for strong winds. && .MARINE... Fresh to strong westerlies will continue through the day today maintaining small craft advisory conditions. Winds and waves will then subside below advisory conditions tonight and Wednesday as a weak surface pressure gradient will be found over the region. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Lakeshore Flood Warning until 4 AM EST early this morning for NYZ006-007. Winter Weather Advisory until 4 PM EST this afternoon for NYZ004>008. Winter Weather Advisory until 6 AM EST early this morning for NYZ019-020. MARINE...Small Craft Advisory until 4 AM EST early this morning for LEZ020. Small Craft Advisory until 7 PM EST this evening for LEZ040-041. Small Craft Advisory until 4 AM EST early this morning for LOZ030. Gale Warning until 4 AM EST early this morning for LOZ043>045-063>065. Small Craft Advisory until 5 PM EST this afternoon for LOZ042. Small Craft Advisory until 4 AM EST early this morning for SLZ022-024. && $$ SYNOPSIS...Hitchcock/RSH/TMA NEAR TERM...Hitchcock/RSH/TMA SHORT TERM...EAJ LONG TERM...JM AVIATION...Hitchcock/JM/RSH/TMA MARINE...RSH/TMA