BuffaloWeather Posted December 22, 2020 Share Posted December 22, 2020 WSW in effect for 1'+ of snow for the area Forecast discussion: .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... ...Heavy Lake Effect Snow Possible Christmas through December 26... The aforementioned system will started to rapidly wrap colder air into the area as the increasingly-curved upper jet structure advances northward through the area on Thursday night. This will rapidly drop 850 hPa temperatures from SW to NE across the area as it does so and change precipitation from rain to snow long before synoptic moisture peels away. This will result in a few inches of snow for almost the entire area before the deeper moisture associated with the system departs. As progressively colder air moves into the region with cyclonic flow entrenched in the area, flow in the 925-850 hPa layer turns southwest on Christmas Day on all guidance, including even the ECMWF at this point (just with a bit of a lag relative to the GFS/Canadian global). Model soundings suggest a deep unstable layer that fully bisects the dendritic growth layer and weak shear within the unstable moist layer. This should allow for good dominant banding to develop first down the length of Lake Erie then a few hours later down Lake Ontario. The persistence of the flow regime on the Canadian is particularly troubling, as the layer averaged flow in the 925-850 hPa layer suggests banding off of Lake Erie right into the Buffalo metro area from Friday right into Saturday for the majority of the time period. While this may be a worst case scenario, it`s also a plausible scenario, as the GFS has been suggesting this for several runs, and the ECMWF layer-averaged flow has taken on a southerly component that makes confidence on lake effect banding making it northward toward the Buffalo metro area very plausible. With the placement of the band in mind, it comes down to snow production efficiency. Bufkit soundings suggest equilibrium levels up toward 10-11 kft by Friday with a lake to 850 hPa delta T of roughly 20C, which combined with cyclonic flow a saturated dendritic layer should result in bands producing 2" per hour snowfall. Depending upon their residency in a particular spot, that could result in a foot or two of snow easily NE of Lake Erie and Lake Ontario, however some shifting of the bands will result in a threat of 9" or more over a broad enough area with confidence commiserate for a winter storm watch for lake effect snow. Watches were thus issued for Thursday night into Saturday in both locations. Lighter lake snows will linger into Sunday and eventually fall apart as warm advection ahead of the next system to affect the area turns flow southerly and warms temperatures into the start of next week. 1 1 Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 GFS with a 3 foot maximum in southtowns Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 Latest GFS might’ve been the best run yet. It is now inside 72 hours before this changeover occurs so in all reality we’re not far off from knowing a more certain outcome Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 All midnight models look good for a near WSW synoptic event, followed by major LES event. 2 Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 Just now, BuffaloWeather said: All midnight models look good for a near WSW synoptic event, followed by major LES event. I don’t think we get WSW criteria from the Synoptic part only. Isn’t it like 7” in 12 hours? Just don’t think this system is going to be around long enough as it’s just a wave developing along the front moving quickly off to the North. Should hopefully be a solid advisory criteria though and be a beautiful sight when we wake up Christmas morning. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 Just now, lakeeffectkid383 said: I don’t think we get WSW criteria from the Synoptic part only. Isn’t it like 7” in 12 hours? Just don’t think this system is going to be around long enough as it’s just a wave developing along the front moving quickly off to the North. Should hopefully be a solid advisory criteria though and be a beautiful sight when we wake up Christmas morning. I can see it, has very strong dynamics. Will have strong snowfall rates. Its not out of realm of possibilities. 3 Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 1 1 Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 5 minutes ago, lakeeffectkid383 said: I like that 21” at KBUF Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 9 minutes ago, BuffaloWeather said: I can see it, has very strong dynamics. Will have strong snowfall rates. Its not out of realm of possibilities. Question is how would they split the 2 up? That would be a lot of public confusion Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 1 minute ago, Thinksnow18 said: Question is how would they split the 2 up? That would be a lot of public confusion they did it in 2010 with winter weather adv and lake snow warning. 1 Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 GEM was weird. Went farther west and still W/NW wind. Tossed Link to comment Share on other sites More sharing options...
wolfie09 Posted December 22, 2020 Share Posted December 22, 2020 Its actually east when it gets north of us . Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 Just now, wolfie09 said: Its actually east when it gets north of us . That track would lead to heavy LES into metro, not NE Ohio, weird placement of max QPF. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted December 22, 2020 Author Share Posted December 22, 2020 BING NWS on LES 345 AM Update... Behind the front, a very cold air mass will descend across the Northeast on Christmas day including snow showers/flurries, with highs in the 20s and lows in the teens and single digits going into the weekend. There will also be a heightened potential for lake effect snow. At this time it appears the flow pattern will be more southwesterly, which will put the area most at risk into western NY and portions of the Finger Lakes from Lake Erie, and from northern Oneida County up to Watertown from Lake Ontario. Conditions look increasingly favorable for a heavy lake effect snow event as very cold temperatures aloft, -13 to -16 deg C, advects across a long fetch of Erie and Ontario. Cleveland NWS .LONG TERM /FRIDAY THROUGH MONDAY/... As previously discussed in the short term forecast, lake effect showers will persist across the snowbelt area for the beginning of the long term forecast. Current models suggest moderate lake induced instability and high equilibrium levels will aid in maintaining organized lake effect snow bands across Lake Erie through Saturday morning. Saturday morning into the early afternoon, a high pressure will build over the area from the south, resulting in winds shifting to southwesterly. This shift in wind should slowly move the greatest chance of lake effect snow out to the northeast and out of our area. This lake effect system is expected to persist for over 24 hours, resulting in a likely significant lake effect snow event. This event will need to continue to be monitored, as any shift in the steering flow would result in possible changes to areas impacted along with snowfall totals. At this point the snowfall totals remain uncertain with the lake effect precipitation. Link to comment Share on other sites More sharing options...
wolfie09 Posted December 22, 2020 Share Posted December 22, 2020 So for the Lake Ontario region the ukmet sends the LP through eastern ny and has a West-WNW flow and crushes Freak lol The European goes through CNY and has more of a West-WSW flow.. We'll have to wait and see what SR guidance shows. 1 Link to comment Share on other sites More sharing options...
ayuud11 Posted December 22, 2020 Share Posted December 22, 2020 6 hours ago, lakeeffectkid383 said: Damm I would take that in a heartbeat but we’ve been screwed so many times with LES events in the metro area it’s ridiculous lol 1 Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 06z GFS and NAM look more of a westerly flow. I wouldn’t be surprised as Wolfie pointed out once the storm gets north of us the storm is further east. Anything is still on the table at this point. In fact 00z GFS run went from 20” at BUF to 8”at 06z. 1 Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 You’re model hugging way too much. Don’t get fooled by the run to run changes. The mean flow will be SW with a shift to WSW for a time and then back to SW. all is good. 1 Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 32 minutes ago, Thinksnow18 said: You’re model hugging way too much. Don’t get fooled by the run to run changes. The mean flow will be SW with a shift to WSW for a time and then back to SW. all is good. We shall see what happens lol. Definitely a possibility that it doesn’t work out for us the way we want to. Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 20 minutes ago, lakeeffectkid383 said: We shall see what happens lol. Definitely a possibility that it doesn’t work out for us the way we want to. Always true with Lake effect!!! It has a mind of its own Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 37 minutes ago, Thinksnow18 said: Always true with Lake effect!!! It has a mind of its own 06z Euro looks like the GFS, not much in the way of synoptic snow anywhere in Upstate. What a turn of events. We still have time for things to change but not the trends we want to see. Maybe no white X mas after all. So 2020 lol. 1 1 Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 4 minutes ago, lakeeffectkid383 said: 06z Euro looks like the GFS, not much in the way of synoptic snow anywhere in Upstate. What a turn of events. We still have time for things to change but not the trends we want to see. Maybe no white X mas after all. So 2020 lol. Are the meso models coming into their timeframe? Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 Through hour 90, smh 2 Link to comment Share on other sites More sharing options...
Geez150 Posted December 22, 2020 Share Posted December 22, 2020 Yup I bet we get a green Christmas and a dusting after that. Link to comment Share on other sites More sharing options...
wolfie09 Posted December 22, 2020 Share Posted December 22, 2020 30 minutes ago, lakeeffectkid383 said: 06z Euro looks like the GFS, not much in the way of synoptic snow anywhere in Upstate. What a turn of events. We still have time for things to change but not the trends we want to see. Maybe no white X mas after all. So 2020 lol. So rough lol How many different ways can we lose out on a snowstorm, starting to lose count..WNY still has a shot at a white Christmas, CNY chances are dwindling.. Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 BUFs first map. Gonna bust big time. Lmao. Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 3 minutes ago, lakeeffectkid383 said: BUFs first map. Gonna bust big time. Lmao. I take...that’s also low end too, right? Don’t they usually have an expected and high end? Wonder what that shows. FWIW they nailed the last map..had KBUF at 2.5 and I believe they ended with 2.6 Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted December 22, 2020 Share Posted December 22, 2020 3 minutes ago, Thinksnow18 said: I take...that’s also low end too, right? Don’t they usually have an expected and high end? Wonder what that shows. FWIW they nailed the last map..had KBUF at 2.5 and I believe they ended with 2.6 That’s expected, low end is 7” at BUF and high end map looks same as expected map with 13” at BUF. Link to comment Share on other sites More sharing options...
vortmax Posted December 22, 2020 Share Posted December 22, 2020 Unfortunately their low-end is 0" for most of us outside LE. Link to comment Share on other sites More sharing options...
Thinksnow18 Posted December 22, 2020 Share Posted December 22, 2020 3 minutes ago, vortmax said: Unfortunately their low-end is 0" for most of us outside LE. They only put in their amounts for their zone...for example they have Geneva )finger lakes) with 3”...that’s not lake effect nor is the 4” for Rochester...still expect 3 to 5 for all areas east of the finger lakes for the synoptic part Link to comment Share on other sites More sharing options...
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