BuffaloWeather

Fresh off the press .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... ...CRIPPLING LAKE EFFECT SNOW STORM POSSIBLE THIS PERIOD... Big picture is that the significant, high-end lake effect event off Lake Erie and Lake Ontario remains on track Thursday night through much of the weekend. There are some subtle differences in steering flow that could impact northern extent of band on Friday especially. Deep H5 trough Hudson Bay to the Great Lakes remains in place Fri/Sat before becoming negative tilted as it shifts across New England on Sunday. In low-levels sfc-H85 low remains across northern Ontario toward Hudson Bay Friday into Saturday with H85 temps at or below -9c. Given water temps averaging 10-12c, this will ensure ample over-water instability with inversions increasing to around 10kft and EQLs a bit higher. Deep moisture advects across the lakes Thu night into Fri night in wake of a shortwave working across the lower Great Lakes. This shortwave will also ignite the lake effect off Lake Erie, rather abruptly after the lake effect on Thursday begins to diminish and soon thereafter to the northeast of Lake Ontario. There is increasing consensus this well developed lake band forms early to mid evening off Erie, but probably just after the tail end of the evening commute. Then, as we typically see it will start 6 hr or so later off Lake Ontario. We are still pretty far out in time from the heart of the event, so forecasts will continue to refine placement of where heaviest snow bands develop. But, there is no change to the thinking that KBUF and KART metro areas are favored, especially later Thursday night through Friday night. This event has some historical precedence, with latest CIPS analogs comparing to Nov 20, 2000, when many became stranded in their vehicles or the more recent twin storms that made `Snow-vember` infamous with over five feet of snow. The pattern suggests this type of high-impact event could occur, but at this point it is impossible to suggest the same magnitude for the upcoming event. Local studies from the KBUF office do support a high-end event with stark similarities in the expected synoptic pattern and for those larger events. The largest events have near stationary plumes of snow with a very sharp northern edge to the band between a ton of snow and very little, but it is still too early to get that detailed. A pattern that certainly favors thunder so kept this in off both lakes as well. Looking more into steering flow, there is decent agreement on a 250- 260 flow backing more to 240-250 flow rest of the night Thursday night which points to band off Lake Erie from Southtowns to downtown Buffalo to Cheektowaga and on into Genesee county. Peak snowfall rates of 2-3" per hour set up late Thursday night. Into Friday, flow starts day 240 so again, Buffalo downtown and into the Northtowns and possibly lifting into southern portions of Niagara and Orleans counties. Band of snow will diminish to the south of the Southtowns and likely shut off alltogether across Chautauqua and Cattaraugus counties. So our watch ends there at that time. Later Friday is where things get a bit muddled. Generally the usually preferred Canadian shows a sharper shortwave crossing and veers winds enough to push us back to a 250-260 flow. Other guidance not on board. Trended ever so slightly toward Canadian idea, but mainly kept the band with 2-3" per hour rates downtown Buffalo to airport with several inches on into western Genesee county but it feasibly could slip back toward the Southtowns if the Canadian idea is correct. Friday night, there is potential that winds back enough ahead of stronger wave that arrives later in the weekend to push band more into Niagara and Orleans counties. Thus, have expanded the watch into those counties as a result. These details will continue to be refined as we move into the warning phase of this event. Turning to Lake Ontario, generally the flow Friday/Friday night and even Saturday will be 230-240, so this appears to be a Watertown/Fort Drum and far northern Jefferson county event. Hit this message in our WSW statement. Preliminary looking more at one to two feet for those areas of northern Jefferson compared to the multiple feet possible for the band off Lake Erie. Later Saturday into Saturday night is when the well developed band appears to be most favored to lift into far western Niagara county or even Canada as sharper re-inforcing upper level and sfc trough dig across the western Great Lakes. This shift to the west of the band is brief though as sharp trough crosses on Sunday. Strong nw flow will sweep southward across both lakes, resulting in brief but heavy snow at times as the main band sweeps quickly southward. While the steering flow will likely oscillate somewhat during the late this weekend and into early next week...a cold southwest flow is mainly what is being shown by most of the guidance packages. This would keep lake snows in place to the northeast of both lakes with additional significant accumulations possible at times even beyond when our initial watches end.

maybe the strength of the band can overcome the thermals?

I'm a season ticket holder so you know I'll be there.

Might be snowed in

Maybe this will sway your mind

GEM

4" max QPF in the heart of erie county.

GFS is very consistent

Don't worry you'll be getting yours soon too. I expect the beginning and end of this event when winds are WNW/W you'll have a good chance at some snow.

Its not easy to track exactly where the bands will go but we have a general idea of the most predominant wind direction which will be SW. SW winds affect Metro Buffalo and 5-10 miles north and south.

If there was ever an event to chase it would be this one. Could be the biggest in quite a few years and looks to hit metro buffalo which would be an easy chase.

It snows for another 2-3 days after the end of this run

NAM coming into range.

If anyone wants an invite to the discord, please send me a PM. Trying to keep it strictly upstate/great lakes posters/chasers. We have 48 posters that have joined so far.

This looks to be a 3/4 part event. RGEM showing 20" for the southtowns tomorrow night/thursday

Thursday A chance of rain and snow showers before noon, then a chance of rain showers between noon and 5pm. Thursday Night A chance of rain and snow showers before 7pm, then snow. The snow could be heavy at times. Low around 26. Chance of precipitation is 90%. Friday Snow. The snow could be heavy at times. Some thunder is also possible. High near 34. Chance of precipitation is 90%. Friday Night Snow. The snow could be heavy at times. Some thunder is also possible. Low around 20. Chance of precipitation is 90%. Saturday Snow. The snow could be heavy at times. Some thunder is also possible. High near 30. Chance of precipitation is 90%. Saturday Night Snow. The snow could be heavy at times. Low around 21. Chance of precipitation is 80%. Sunday Snow. The snow could be heavy at times. High near 31. Chance of precipitation is 80%. Sunday Night Snow. The snow could be heavy at times. Low around 20. Chance of precipitation is 80%.

I got a spare bedroom if anyone needs to crash. I believe I will be south of the hardest hit area this time. Might go stay at my dads house near the airport. Winds look primarily out of the SW for majority of this event which would land all of metro buffalo in the crosshairs. The last time I saw crippling from Buf NWS was from Nov 2014 where I got 88" in 3 days.

Lake Erie is at a record high for the date at 54 degrees.

If there are any chasers out there. Buf NWS calling for feet of snow this week. I haven't seen them use crippling in a forecast discussion since Nov 2014. Could be an all timer ...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY EVENING THROUGH SUNDAY EVENING... * WHAT...Heavy lake effect snow possible. Total snow accumulations in this long duration event of MULTIPLE feet will be possible in the most persistent lake snows. LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ...CRIPPLING LAKE EFFECT SNOW STORM POSSIBLE THIS PERIOD...

If there are any chasers out there. Buf NWS calling for feet of snow this week. I haven't seen them use crippling in a forecast discussion since Nov 2014. Could be an all timer ...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY EVENING THROUGH SUNDAY EVENING... * WHAT...Heavy lake effect snow possible. Total snow accumulations in this long duration event of MULTIPLE feet will be possible in the most persistent lake snows. LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ...CRIPPLING LAKE EFFECT SNOW STORM POSSIBLE THIS PERIOD...

This mornings runs GFS RGEM

First part of the event forecast totals

Also calls the event crippling! .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ...CRIPPLING LAKE EFFECT SNOW STORM POSSIBLE THIS PERIOD... No change in available model output and overall H85 and H5 pattern for late this week into the weekend. There remains high confidence that a prolonged southwest flow lake effect event will take place during this period. A deep longwave trough...featuring a vertically stacked low in the vicinity of Hudson Bay...will keep a flow of seasonably cold air in place over the Lower Great Lakes through the weekend to GUARANTEE a lake response. The `formula` for significant lake snow will then come down to whether there is ample synoptic moisture to work with...and of course the direction of the H85 steering flow. Consensus of both ensemble and deterministic guidance packages are in fairly strong agreement of a southwest flow...but placement of accumulating snow bands will have to be further defined as the event nears. Continues to look like KBUF and KART metro areas and their northern suburbs (at least for a time) are favored. This event has some historical precedence, with CIPS analogs comparing to Nov 20, 2000, when many became stranded in their vehicles...or the twin storms that made `Snow-vember` infamous with over five feet of snow? While at this point it is impossible to suggest the same for the upcoming event...it is something to keep in mind. Speaking of correlations...local studies from the KBUF office does show some stark similarities in the synoptic pattern for these larger events. The largest events have near stationary plumes of snow...but it is still way too early to get that detailed. In the wake of a passing shortwave ridge on Thursday...subtle troughing embedded within in the larger scale longwave pattern will produce a deep southwest flow of cold air across Lakes Erie and Ontario. There is a suggestion that the flow will generally be 250- 260 Thursday evening...but with the lakes still relatively warm (nr of abv 10c)...that flow could back some 10 deg over Lake Erie. During the course of Thursday night and Friday...the flow is forecast to back a bit...and this will send well organized lake snow plumes across the Buffalo and Watertown metro areas and potentially into the northern suburbs. Again, placement of these bands will depend on the exact H85 flow...but a southwest (240-250) flow is being favored by guidance at this time. Given the expected presence of moisture up to arnd H7...snowfall rates of 1-2"/hr is becoming more plausible. Details still have to be refined, but there was enough signal and consistency in model guidance to issue winter storm watches Thursday evening through Sunday evening for a potential high impact, long duration lake snow event. If winds back further for longer period of time, then Niagara and Orleans counties would need to be put in a watch as well. Those details can be sorted out next couple days though. While the steering flow will likely oscillate somewhat during the course of the weekend and into early next week...a cold southwest flow is mainly what is being shown by most of the guidance packages. This would keep lake snows in place to the northeast of both lakes with additional significant accumulations possible at times even beyond when initial watch ends.