ayuud11 Posted November 18, 2015 Share Posted November 18, 2015 Polar Vortex at end of GFS run. Latest blog post by Judah Cohen The polar cap geopotential height anomaly plot continues to show a strong polar vortex into the foreseeable future (not shown). However some slight increase in wave activity flux in week two is predicted to perturb the stratospheric polar vortex so that it becomes less circular and more elongated (Figure 7). The counter clockwise flow around the polar vortex would help transport cold air from Siberia and drive it into North America east of the Rockies. This pattern is reminiscent of the dominant winter pattern of the past two winters that resulted in extremely cold winters in the eastern United States. The possibility of transport of cold air from Siberia into the Central and Eastern United States is something to watch as we officially begin winter. However we do not anticipate this to necessarily be the dominant winter pattern as we expect further disturbing of the polar vortex and longer term implications as we discuss in the next section. 30–day As we have shown in our research the favored high latitude atmospheric pattern in November that follows above normal October Eurasian snow cover extent is the expansion of the Siberian high across northwest Asia with low pressure to the east near the Aleutians and a secondary area of low pressure in the northern North Atlantic; a pattern that we refer to as the tripole pattern (Cohen and Jones (2012)). The current atmospheric pattern strongly projects onto this pattern. This same pattern also favors the increase in wave activity flux or the vertical transfer of energy from the troposphere to the stratosphere during the month of December. At AER we have developed a polar vortex model that predicts the strength of the polar vortex one month in advance. It is predicting a major sudden stratospheric warming (SSW) in mid-December. We currently feel that this forecast is unlikely because the model is overly sensitive to SSW and has many false positives and because a major SSW is relatively rare in December. Still given the polar vortex model forecast and strong projection of the current atmospheric pattern onto the tripole pattern, we are more confident in increased wave activity flux in December that will result in weakening of the polar vortex in December and likely continuing into January. Also because the current dominant high latitude circulation is a wave two pattern, this would favor a polar vortex split relative to a polar vortex displacement in the event of a significant weakening of the polar vortex. One inhibiting background factor is the westerly phase of the quasi-biennial oscillation (QBO) that favors a strong vortex over a weak vortex. But if our expectations of a weakened polar vortex verify, this will likely favor an increased likelihood of severe winter weather across the continents of the Northern Hemisphere. Of course all of this is highly speculative but the purpose of this blog is to push the boundaries of what is possible in weather forecasting beyond the skillful range of the weather models. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 18, 2015 Author Share Posted November 18, 2015 Nice video Buf, I gotta say I'm getting more excited for the weekend, 18z goofus looked good so we shall see. I think we can be on first name basis Ayuud, call me Rich. And yes I agree I see a potential for the first Lake effect snow watches coming for areas affected on W/NW flow. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 18, 2015 Author Share Posted November 18, 2015 Latest blog post by Judah Cohen Awesome, thanks for posting! I love reading his posts, winter may have an actual chance this year. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 18, 2015 Author Share Posted November 18, 2015 It gets cold after thanksgiving Link to comment Share on other sites More sharing options...
ayuud11 Posted November 18, 2015 Share Posted November 18, 2015 I think we can be on first name basis Ayuud, call me Rich. And yes I agree I see a potential for the first Lake effect snow watches coming for areas affected on W/NW flow. The GFS has a mainly a WSW-W'ly flow for most of the time Sunday. Link to comment Share on other sites More sharing options...
AppsRunner Posted November 18, 2015 Share Posted November 18, 2015 Nice W/WSW flow off Erie plus a nice W/WnW flow off Ontario on the GFS. Euro looked relatively similar Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 18, 2015 Author Share Posted November 18, 2015 I see a w/nw event where are you seeing sw? Link to comment Share on other sites More sharing options...
scottmartin49 Posted November 18, 2015 Share Posted November 18, 2015 Looks like the JMA is calling winter off for us; http://ds.data.jma.go.jp/tcc/tcc/products/model/map/4mE/map1/pztmap.php From that. the only hope is for a SSW to crack the vortex,but that's a gamble- the cold can drop anywhere! Link to comment Share on other sites More sharing options...
AppsRunner Posted November 18, 2015 Share Posted November 18, 2015 I see a w/nw event where are you seeing sw? Sorry, you're definitely right. I had looked at a couple charts in class when the winds start to back out of the WSW at the end of the event, and just didn't look closer then that. Either way, GFS/ECM have been relatively consistent in their solutions, with the GFS wavering back and forth between pure Westerlies to WNW'erlies. BUF has put 70% pops in for Oswego for Saturday Night-Sunday night! Link to comment Share on other sites More sharing options...
AppsRunner Posted November 18, 2015 Share Posted November 18, 2015 And BUF's AFD for those who haven't seen it. Should be interesting to see if we can actually manage of Huron connection with WNW flow. I truly haven't seen a band stay over Oswego for more than 3-4 hours in my time here, so I'm cautiously optimistic about this! HOWEVER BYSUNDAY MORNING...PRECIPITATION ACROSS THE SOUTHERN TIER SHOULDRAPIDLY CHANGE ENTIRELY OVER TO SNOW AS THE LOW LIFTS ACROSS THEOTTAWA VALLEY AND STRONG WESTERLIES WRAP COLDER AIR AND MOISTUREBACK ACROSS THE AREA...SETTING UP WHAT MAY BE THE FIRST SIGNIFICANTLAKE EFFECT EVENT OF THE SEASON FOR PORTIONS OF THE FORECAST AREA ONSUNDAY. SEE THE LONG-TERM DISCUSSION BELOW FOR MORE DETAILS...&&.LONG TERM /SUNDAY THROUGH WEDNESDAY/...AS SATURDAY`S LOW MOVES OFF INTO QUEBEC SUNDAY...ALL OF THEINGREDIENTS APPEAR TO BE IN PLACE FOR A BRIEF BUT POTENTIALLYSIGNIFICANT LAKE EFFECT EVENT ACROSS THE WESTERN SOUTHERN TIER ANDOFF OF LAKE ONTARIO ACROSS THE TUG HILL PLATEAU. ENSEMBLES ARE INEXCELLENT AGREEMENT ON THE SYNOPTIC SETUP ACROSS THE REGION WITH ASURFACE/MID-LEVEL LOW LIFTING OFF TO THE NORTHEAST ACROSS QUEBEC ANDA SHARP UPPER LEVEL TROUGH UPSTREAM ACROSS THE CENTRAL GREAT LAKES.COLD AIR WRAPPING IN BEHIND THE SURFACE/MID-LEVEL FEATURES WILLADVECT ACROSS THE LAKES ON WESTERLY FLOW AND AS 850MB TEMPS FALL TO -10C...EQUILIBRIUM LEVELS WILL CLIMB ABOVE 15KFT BY DAYBREAKSUNDAY MORNING. WHILE DIURNAL EFFECTS SHOULD HAMPER BANDDEVELOPMENT TO SOME EXTENT DURING THE DAY ON SUNDAY...SYNOPTICLIFT FROM THE UPPER LEVEL TROUGH MAY COMPENSATE FOR THIS AS ITMOVES THROUGH BY SUNDAY EVENING WITH A BRIEF PERIOD OF POTENTIALUPSTREAM CONNECTION OFF OF LAKE HURON AS FLOW VEERS TO THE WNWLATER IN THE DAY AND INTO SUNDAY EVENING. INCREASING SHEAR SUNDAYNIGHT IN THE WAKE OF THE UPPER LEVEL TROUGH PASSAGE SHOULD BRINGAN END TO THE BULK OF THE SNOW BY MONDAY MORNING OFF OF LAKE ERIEAND AROUND MIDDAY OFF LAKE ONTARIO. Link to comment Share on other sites More sharing options...
scottmartin49 Posted November 19, 2015 Share Posted November 19, 2015 Until you've lived through one where they're snowblowing off the porch (and other) roofs for the second time, you haven't seen anything. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 19, 2015 Author Share Posted November 19, 2015 And BUF's AFD for those who haven't seen it. Should be interesting to see if we can actually manage of Huron connection with WNW flow. I truly haven't seen a band stay over Oswego for more than 3-4 hours in my time here, so I'm cautiously optimistic about this! Yeah, you should be in a good spot for this. Maybe just north of your location. Keep us updated! Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 19, 2015 Author Share Posted November 19, 2015 Until you've lived through one where they're snowblowing off the porch (and other) roofs for the second time, you haven't seen anything. They had snowblowers in 77? Link to comment Share on other sites More sharing options...
scottmartin49 Posted November 19, 2015 Share Posted November 19, 2015 They had snowblowers in 77? Yup. Fire, beer, and snowblowers in that order. It's what we call 'civilization'. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 19, 2015 Author Share Posted November 19, 2015 I'm at work but Tom Niziol just posted the RPM on his facebook that shows a really strong band of lake effect snow over Metro Buffalo Sunday Morning. He got me a tad excited. Link to comment Share on other sites More sharing options...
Buffalo Bumble Posted November 19, 2015 Share Posted November 19, 2015 BUF is at +7.4 for the month. I don't see this changing too much with another big time warm-up looking likely around T'giving. I would be interested in what the analogs say for winter temp/snowfall after such a torch November. Link to comment Share on other sites More sharing options...
WNash Posted November 19, 2015 Share Posted November 19, 2015 Niziol on Facebook, from an RPM run this morning, for 6:30 AM on Sunday. Nice intense band into the city, if it were to play out. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 19, 2015 Author Share Posted November 19, 2015 BUF is at +7.4 for the month. I don't see this changing too much with another big time warm-up looking likely around T'giving. I would be interested in what the analogs say for winter temp/snowfall after such a torch November. Strong El Ninos almost always mean a warmer winter, snowfall is unpredictable though, especially because lake effect represents 50-60% of our snowfall. Link to comment Share on other sites More sharing options...
WNash Posted November 19, 2015 Share Posted November 19, 2015 Strong El Ninos almost always mean a warmer winter, snowfall is unpredictable though, especially because lake effect represents 50-60% of our snowfall. Persistent snow cover will probably be tough to have - hope ski country can get through this OK. But an open lake in Feb/Mar might give us plenty of opportunities in what are typically lower snowfall months. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 20, 2015 Author Share Posted November 20, 2015 Cold looks like a good call after thanksgiving. GFS is more progressive but GEM and Euro have some good cold moving in. GEM EURO GFS Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 20, 2015 Author Share Posted November 20, 2015 The lake effect may start out on a SW flow before veering Sunday Afternoon, but there is another shortwave moving in very early Monday morning which may swing the band back north and provide some synoptic lift to the band as temps should still be cold enough until the afternoon where dry air moves in and chokes the band off. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 20, 2015 Author Share Posted November 20, 2015 I think off of Ontario places just north of Oswego and typical Tug will do good with this event. Probably some foot totals up there. Link to comment Share on other sites More sharing options...
AppsRunner Posted November 20, 2015 Share Posted November 20, 2015 LES Watches out for the typical Tug Hill (Lewis, Jefferson, Oswego) and Chautauqua Ridge counties. Up to a foot possible in both locations it appears. 4km NAM briefly drops the band down to Oswego Sunday night with 280 flow. Hopefully we actually see some snow! Link to comment Share on other sites More sharing options...
wolfie09 Posted November 20, 2015 Share Posted November 20, 2015 Would be nice to see some white on the ground Link to comment Share on other sites More sharing options...
scottmartin49 Posted November 20, 2015 Share Posted November 20, 2015 Ever used this one for snowfall prediction/probs? It tends to be a lot more accurate; http://www.wpc.ncep.noaa.gov/pwpf/wwd_accum_probs.php?fpd=24&ptype=snow&amt=1&day=2&ftype=probabilities Link to comment Share on other sites More sharing options...
BuffaloWeather Posted November 21, 2015 Author Share Posted November 21, 2015 Would be nice to see some white on the ground Nice. Weird that the discussion says Ontario will do much better than Erie yet have higher accumulations off Erie... I think we see some 12-18" totals off both lakes by Monday Afternoon. I may have a chance at a few inches as well. Link to comment Share on other sites More sharing options...
WNash Posted November 21, 2015 Share Posted November 21, 2015 Ever used this one for snowfall prediction/probs? It tends to be a lot more accurate; http://www.wpc.ncep.noaa.gov/pwpf/wwd_accum_probs.php?fpd=24&ptype=snow&amt=1&day=2&ftype=probabilities No, I haven't found the WPC 24/48/72 maps produced in Maryland 2x daily to show more predictive accuracy than the maps produced by the Buffalo WFO. It's nice that they harmonize between WFOs - I know that the disjuncts on map edges between offices drive some people bonkers - but professional mets at local forecast offices tend to have a better understanding of local conditions in general, and with the peculiarities of lake weather, that means even more at the Buffalo office. Link to comment Share on other sites More sharing options...
AppsRunner Posted November 21, 2015 Share Posted November 21, 2015 A few models have showed what appears to be an anticyclonic curved band across portions of Oswego and Lewis counties Sunday night. Still plenty of time to go but at least a general 2-4" seem like a decent bet outside the Tug, with more on the Tug itself Link to comment Share on other sites More sharing options...
scottmartin49 Posted November 21, 2015 Share Posted November 21, 2015 No, I haven't found the WPC 24/48/72 maps produced in Maryland 2x daily to show more predictive accuracy than the maps produced by the Buffalo WFO. It's nice that they harmonize between WFOs - I know that the disjuncts on map edges between offices drive some people bonkers - but professional mets at local forecast offices tend to have a better understanding of local conditions in general, and with the peculiarities of lake weather, that means even more at the Buffalo office. Maybe that works if you live at 'ground zero' for a great WFO like Buffalo. For me, right at the far boundary of three different ones (and directly subject to the worst of the three), the WPC maps are always more accurate. Buffalo is a (semi) close second if I punch in the zip code three miles west of me. Link to comment Share on other sites More sharing options...
WNash Posted November 21, 2015 Share Posted November 21, 2015 Maybe that works if you live at 'ground zero' for a great WFO like Buffalo. For me, right at the far boundary of three different ones (and directly subject to the worst of the three), the WPC maps are always more accurate. Buffalo is a (semi) close second if I punch in the zip code three miles west of me. Yeah, you're subject to that special frustration of map edges. And it doesn't surprise me that some WFOs do a poor job outside what they see as the key population or weather origination areas, so it makes sense that the WPC forecasters, just by weighing every area equally, do a better job. That sucks, and if you're getting higher accuracy from less frequent larger scale forecasting, that is a flaw in the system. Link to comment Share on other sites More sharing options...
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