536 FXUS61 KBUF 061441 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 941 AM EST Sun Dec 6 2020 .SYNOPSIS... Light snow showers and patchy freezing drizzle southeast of the lakes today will taper off late this afternoon. Below normal temperatures will continue into the new work week, with a warming trend starting mid week. Above normal temperatures through weeks end is expected. Quiet weather for most of the new week, with just a chance for some precip on Wednesday and the weekend. && .NEAR TERM /THROUGH TONIGHT/... Regional radar shows very light returns across the region this morning. Northwest flow and low level moisture has resulted in very light snow showers or flurries for a majority of the area however freezing drizzle has been observed just south of Oswego and northern Cayuga counties this morning. With light returns being picked up across Oswego county patchy freezing drizzle is possible southeast of Lake Ontario. This morning, the shortwave trough will round the base of a larger scale trough over the region. With 850H temps of around -10C, combined with the forcing from the passing shortwave trough, a weak lake response is expected to develop. The shortwave trough will track over the area through early this morning. After this trough passage, the response off the Lakes will weaken through the day. The limiting factor with the lake response will be the lack of synoptic moisture. Moisture will be limited to the lowest few thousand feet with the contribution from the Lakes. Most of the snow showers and flurries that do develop should be south of Lake Ontario with the northwest flow over the lakes. Snowfall today of around a half inch will be possible for the Northern Finger Lakes area, with lesser amounts west and east. Areas outside of the snow showers but still downwind of the Lakes can expect mostly cloudy skies today with a continued weak lake response. Some areas of the North Country will see some decreasing clouds later in the afternoon. Temperatures today will be in the upper 20s to low 30s for areas south of Lake Ontario, and for areas east of Lake Ontario, in the low 20s over the Tug Hill to low 30s for the lower terrain. Today's highs will be the coldest temperatures that some areas have experienced since last winter. Tonight, any snow showers or flurries that linger into the evening should continue to dissipate through the night. Snow showers that do continue through the evening may produce a coating of snow for areas southeast of Lake Ontario. Clouds will continue through the night, especially south of Lake Ontario. Temperatures tonight will be in the mid teens to low 20s east of Lake Ontario, and in the upper teens to mid 20s south of Lake Ontario. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... On Monday, upper low with sub 990mb sfc low will be over the Gulf of St. Lawrence while high pressure ridge builds from Ontario to the western Great Lakes. Weak slightly cyclonic and marginally cool west- northwest flow between these two features will result in good deal of cloud cover across region, but not much in way of snow showers. Moisture only extends to -10c per soundings, but it is also pretty dry below cloud base. A few flurries or isolated snow showers probably covers this scenario. Possible that this activity flares up Monday afternoon as weak shortwave/deeper moisture drop across especially southeast Lake Ontario region to the North Country. In any case, little if any snow accumulation is expected. For sure a chilly day with highs near 30 into lower 30s even for the lake plains. High pressure building in and modifying temps aloft leads to dry weather rest of the period into Tuesday night. Will still be on the cool side of normal with readings in the lower to middle 30s most areas on Tuesday. Nighttime lows will be in the teens and 20s both Monday night and Tuesday night. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Shortwave sliding through on Wednesday ahead of stronger warm air advection late this week will bring rain and snow to region. Temps over higher terrain of eastern Lake Ontario region including Tug Hill and western Dacks should stay cold enough for lake enhanced snow. Some accumulation could occur Wednesday into Wednesday night. ECMWF quite bullish with qpf/snow and seems on higher end of guidance for both. H85 temps of -4c to -6c marginal for all snow and suggest we'll be looking at situation that is highly dependent on elevation. Will keep this out of HWO for now given most guidance is not as bullish with qpf/snow as ECMWF and since ECMWF showed sharp increase over its previous runs. Beyond this into late this week, upper ridging and warming will provide a warm up with temps rising well above normal Thu into Sat. Deepening long wave trough over central CONUS will then result in cyclogenesis by next weekend with deepening low potentially less than 990mb lifting across the western Great Lakes. At least at this point, primary models are in good agreement with the idea, though NBM temp output shows decent spread Friday and Saturday. Seems we'll be on the warm side of the system Friday/Saturday (highs potentially as warm as the 50s one or both of these days) with rain first part of the weekend and possibly some gusty winds and increasing lake effect snow chances arriving by late next weekend as colder air arrives from the west. Plenty of time to dive into those details as we work through the upcoming week. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... Upslope flow keeping cigs in the IFR or MVFR range at all TAF sites through the morning. There will be gradual improvement, but most cigs should stay MVFR in persistent lake effect stratus with scattered snow showers. The greatest snow shower coverage will be south of Lake Ontario toward the Finger Lakes. Local IFR vsby possible in scattered snow showers southeast of the lakes. Periods of VFR expected for KART this afternoon. Outlook... Monday and Tuesday...VFR. Wednesday and Thursday....Mainly VFR. A chance of rain or snow showers. && .MARINE... Winds will weaken some through the morning as the pressure gradient over the region weakens. Northwest winds will result in choppy conditions on both lakes today. Winds on the lakes should maintain a gentle to moderate breeze through most of Tuesday. Winds will maintain a north to northwesterly direction, shifting to the west through the day Tuesday. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...SW NEAR TERM...HSK/SW SHORT TERM...JLA LONG TERM...JLA AVIATION...SW/TMA MARINE...SW