BuffaloWeather

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... ...CRIPPLING LAKE EFFECT SNOW STORM POSSIBLE THIS PERIOD... A strong ridge of high pressure extending to Alaska and NW Canada leading up to this period`s start will dislodge a plume of arctic air southward, flowing down across the Great Lakes within a deep trough of low pressure over Hudson Bay and to the Great Lakes. Temperatures at 850 hPa will lower to -10/-11C over the warm Great Lakes, with delta T`s between the lake surface and 850 hPa of at least 20C. This will bring plenty of lake instability to help in formation of lake bands of precipitation. This cold airmass will linger over the Lakes through this period, producing not only lake snows, but also much below normal surface temperatures. To start this period a surface low will be near the SOO, with weak surface ridging pulling off to the east. A shortwave will be nearing the east end of Lake Erie, and together these features will back the surface winds. A secondary shortwave crossing southern Lake Michigan early Friday morning will allow for general southwest flow to continue for 24-36 hours, bringing significant lake snow accumulations where bands persist the longest. Off Lake Erie... Backing surface winds will bring the focus of the lake snows northward towards the metro Buffalo area. In doing so there may be a disruption in the lake band briefly in the early evening, but strong surface convergence and upward omega forcing, combined with increased moisture with the passing shortwave should allow a singular band of precipitation to again quickly establish. The cooling aloft will allow for primarily snow, though near lake shore mix remains possible early Thursday evening. Once this band sets up, it will remain fairly stationary late Thursday night and through the day Friday with the synoptic pattern forcing a general southwest flow. The strong convergence leading to impressive omega values, along with deep moisture in the snow DGZ and lake induced equilibrium levels rising to over 20K feet will allow this band of snow oriented along the long axis of the lake to become very strong with snowfall rates up to 3 inches per hour. Seeing how this narrow, intense band of snow will not oscillate much later Thursday night and through Friday and into Friday night snowfall totals will easily reach several feet this period. The highest totals may very well end up across the Buffalo Metro area, including downtown and towards the airport where a 240 wind flow will direct the snowband. Climatologically, the northern flank of this snowband will have a very tight gradient, while the southern flank will have accumulations fan out with lesser gradient. This tight gradient usually occurs when the lake is still warm, with a cold airmass overhead as well as equilibrium levels up towards 500 hpa. This northern flank is also where we expect the stronger inbound winds as well as the highest snowfall rates to occur. Will have confidence to upgrade northern Erie and Genesee Counties to a lake effect snow warning, though there is still some question to whether the band will clip the NW corner of Wyoming. For this reason we will leave Wyoming in a watch...as well as Niagara and Orleans due to the later impacts of the snowbands. The higher lake equilibrium levels as well as well as increased lake instability may bring a few rumbles of thunder within the lake snow band. This may occur later Thursday night and through Friday night...with lightning possible over Lake Erie and to about 20-25 miles inland. Off Lake Ontario... Winds will back about 3 hours later off Lake Ontario such that to start this period lake snows will be oriented over Oswego and southern Lewis. A quick backing of the winds will steer the lake bands northward quickly, towards Watertown just past midnight. Once this lake effect snow band sets up through the overnight, it will remain fairly stationary through the day Friday with the synoptic pattern forcing a general southwest flow. The strong convergence leading to decent omega values, along with deep moisture in the snow DGZ and lake induced equilibrium levels rising to over 20K feet will allow this band of snow to oriented towards Jefferson County with the snowfall rates of 3 inches per hour. The axis of greatest snowfall this period will likely be directed at Watertown and towards Philadelphia. Though the snow band will not be oriented along the long axis of Lake Ontario, an upstream connection to Lake Erie snowband will likely enhance the snows over Jefferson County allowing for similar snowfall rate potential. Here snowfall totals will also be measured in feet, and will upgrade the watch to a Lake Effect snow warning for Jefferson County. The snow band initially clipping southern Lewis will then clip the northern portion of the county through the day Friday and Friday night. While the band of snow will not focus entirely on Lewis, several inches to half a foot of snow each period will allow for a long duration advisory. There will also be the potential for thunder to occur within the more intense portion of the Lake snowband over Lake Ontario and into the western half of Jefferson County. Likewise to Lake Erie, the taller lake equilibrium heights and high delta T`s will create an environment that will allow for charge separation and lightning to occur. Off both Lakes... Winds will begin to increase during the day Friday. Gusts towards 35 mph near the shoreline will create blowing snow...that with the heavy snowfall will lower visibilities at times to just a few hundred feet. Travel late Thursday night and through Friday night will be very difficult. A deeper shortwave trough will bear down upon the eastern Great Lakes late Friday night. This will back the surface winds further such that the bands of snow will lift northward towards Niagara-Orleans as well as the Saint Lawrence Valley. More on this in the long term discussion below. Outside of the lake effect snowbands the weather will be fairly quiet. Skies will begin to clear some during the day Friday, though still cold. The clear skies Friday night outside of the lake plumes will bring a cold night, with overnight lows 10 to 15F across the inland Southern Tier as well as the southern Tug Hill. Apparent temperatures in these regions will drop into the low single digits Friday night. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 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-enforcing 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.

Lake effect snow warnings in place! ...LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 7 PM THURSDAY TO 1 PM EST SUNDAY... * WHAT...Heavy lake effect snow expected. Total snow accumulations of 2 to 3 feet in the most persistent lake snows. The heaviest snow is expected late Thursday night through Friday night when snowfall rates could exceed two inches per hour. Snowfall totals of up to 4 feet will be possible if the main snow band is slower to push north late Friday night. Winds gusting as high as 35 mph. * WHERE...Northern Erie and Genesee counties. * WHEN...From 7 PM Thursday to 1 PM EST Sunday. ...LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 7 PM THIS EVENING TO 1 AM EST SATURDAY... * WHAT...Heavy lake effect snow expected. Total snow accumulations of 1 to 3 feet in the most persistent lake snows. The highest accumulations will be inland from the lake across the higher terrain. Winds gusting as high as 35 mph. * WHERE...Southern Erie county. * WHEN...From 7 PM this evening to 1 AM EST Saturday.

RGEM NAM

Tonights runs drifted a little south with the band and slightly increased QPF. GFS GEM

Elma ny had 98” in November 2014, I had 88” here. Buffalo airport record is dec 2001 event at 82”. 2007 is biggest event on record at tug hill 10 day totals of 140”

If I wasn't excited before I'm officially excited now. Lake effect king called for 40"+ this morning in our discord. What are your thoughts on lightning, band placement/strength, residence time? I might be too far south for this one. Trying to figure out my game plan as my dad lives near the airport and might be better positioned.

Through Friday at 7 am

Looks about the same, slightly south. 4" of QPF in hardest hit area.

There is potential for that. Some are talking about having the game in Detroit as we play Detroit on thanksgiving.

Thats from accuweather which is obviously hyping it up. But the local National weather service is projecting similar totals of multiple feet. All 3 globals show 40-60" of snow with 3-5" of QPF.

The RGEM with an insane run. 5" of QPF over my house. The band will still be going for 48 hours after this run ends.

I got season tickets so I'll be there as well.

18z NAM goes a little south with the band. The band is still going for 2-3 days after the end of this run. Not sure what ratios will be but early season events are usually lower than later season events when the lake and air is colder. Probably looking at 1:13-1:16 ratios.

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.