BuffaloWeather

Nov 14 redux on hrrr

Latest HRRR goes a little nuts across metro-southtowns by friday afternoon 3.6" of QPF

HRRR

HRDPS has a dual band, this is only through friday morning

WPC: ...Great Lakes... Days 1-3... ***Major lake effect snow event likely to begin tonight and last through the upcoming weekend*** A long duration and heavy lake effect snow event is likely to begin late Wednesday and then ramp up impressively through Friday as a large scale trough envelops the eastern 2/3 of the CONUS and mean layer flow becomes northwesterly across the Upper Great Lakes and west-southwesterly over the Lower Great Lakes. Embedded within this trough, spokes of shortwave energy will rotate cyclonically from NW to SE, producing rounds of enhanced ascent and re-energizing the subsequent CAA. Lake water temperatures according to GLERL range from as warm as +6C in Lake Superior to as high as +14C in Lake Erie and Lake Ontario. Pronounced CAA through the period will drop 850mb temps from -6C to -10C Wednesday, to as low as -10C to -15C Friday, creating intense lake-induced instability reaching potentially 2000 J/kg as inversion heights climb towards 10,000 ft. While wind trajectories will vary at times with the passage of each shortwave, shear should become ideal at times for single intense bands of LES, especially downwind of Lake Erie and Ontario, with some additional moisture /effective fetch/ off Lake Huron aiding. Additionally, this intense instability and lake wind convergence could result in meso-lows over Lake Superior to additionally enhance LES at times. For D1, the most intense LES is forecast south of Lake Michigan and eventually to the east-southeast of Lake Erie and the Chautauqua Ridge into D2 due to multi-bands developing across Erie. A few snow squalls may also extend eastward across parts of northern PA on Thursday away from Lake Erie underneath a cutting shortwave and within steep low-level lapse rates. WPC probabilities are above 90% for 4 inches on D1 downwind of southern Lake Michigan and east of Lake Erie, with locally 12 inches possible as convective snowfall rates eclipsing 2"/hr become likely. Additional moderate-to-heavy LES is likely D2 and D3 in the western U.P., as well as L.P., of MI. The most significant LES during this forecast period appears to occur Friday as shear becomes westerly over Lake Michigan and Superior, becoming W/SW over Lake Erie and Ontario. This occurs in conjunction with additional tumbling of 850mb temps to enhance instability, and convective snow rates moving onshore of many of the typical lake effect belts are progged for Friday. Heavy snowfall from the Bayfields Peninsula through the Keweenaw is expected, along with multiple bands shifting onshore from near Grand Rapids to Traverse City, MI. In these areas, WPC probabilities for more than 6 inches are higher than 80%, with locally much higher totals likely. Downstream of Lake Erie and Ontario, potent, convective, single bands are becoming more likely Friday as fetch becomes ideal and aimed right at the Buffalo metro area. Extreme snowfall rates of 3"/hr into parts of Upstate NY are possible. WPC probabilities are high for 12 inches of snow within 24 hours ending 00z 11/19, with locally much higher totals measured in multiple feet possible near Buffalo, NY over the course of the entire forecast period. This lake effect event will continue through the upcoming weekend with additional significant accumulations likely. The medium range discussion from WPC outlines some of this additional threat. Key Messages for Lake Effect Snow in the Great Lakes: --Confidence is increasing that several days of heavy lake effect snow will occur east of the Great Lakes through the upcoming weekend. --Lake effect snow is expected to begin late Wednesday, with periods of heavier snow continuing through Sunday. The most intense snowfall will occur Thursday into Friday. --Snowfall will at times likely be accompanied by lightning, thunder, and rates exceeding 2�/hr. This will produce near zero visibility and snow covered roadways making travel hazardous to nearly impossible.

70% props of 12+

Some of the high res getting within range

https://www.thruway.ny.gov/travelers/map/text/twytextcameras.cgi?region=BUI90B This link will cover the entire band of snow.

As the lake effect expert on this board what are your thoughts on this event further north near Buffalo? Trying to find the best location to ride this out in. Was thinking 2-3 miles south of the airport? Any chance at thundersnow?

Any chances at thundersnow? Where would you target for hardest hit areas? I was thinking just south of the airport in the Cheektowaga area.

I will be! I live for these events! Quite a few chasers on this one. I think we have all of Erie county covered. This one looks to hit slightly north of Nov 2014 right across heart of the Metro Buffalo area. Trying to figure out my chase plan if I'm too far south. A lot of times with these events they have driving bans and tough to get anywhere.

The NAM having lower QPF gives me some pause on the higher numbers. Would still be a big storm but it paints less then half of the QPF that the RGEM is showing.

So whose coming to chase?

Accuweather going big

Just a longer fetch with the wind direction. Accuweather going big

Only through 9 am Saturday

Kbuf official map through 7 am Saturday

Don't think I remember ever seeing KBUF forecast 3-4' of snow before the band starts going off the lake.

Tonight A chance of snow showers between 8pm and midnight, then snow likely after midnight. Mostly cloudy, with a low around 31. West wind 5 to 10 mph. Chance of precipitation is 70%. New snow accumulation of around an inch possible. Thursday A chance of snow showers before 1pm, then a slight chance of snow showers after 2pm. Mostly cloudy, with a high near 38. West wind 11 to 16 mph, with gusts as high as 28 mph. Chance of precipitation is 40%. New snow accumulation of less than a half inch possible. Thursday Night A slight chance of snow showers before 8pm, then snow, mainly after 8pm. The snow could be heavy at times. Some thunder is also possible. Low around 27. Southwest wind 6 to 15 mph. Chance of precipitation is 100%. New snow accumulation of 10 to 16 inches possible. Friday Snow. The snow could be heavy at times. Some thunder is also possible. Areas of blowing snow after noon. High near 35. Southwest wind 11 to 15 mph, with gusts as high as 26 mph. Chance of precipitation is 100%. Friday Night Snow, mainly before 1am. The snow could be heavy at times. Some thunder is also possible. Areas of blowing snow before 9pm. Low around 20. Chance of precipitation is 100%. Saturday Snow before 1pm, then snow showers likely after 1pm. The snow could be heavy at times. High near 30. Chance of precipitation is 100%. Saturday Night A chance of snow showers. Mostly cloudy, with a low around 21. Chance of precipitation is 50%. Sunday Snow showers. High near 31. Chance of precipitation is 80%.

.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.