Ian Posted June 20, 2011 Share Posted June 20, 2011 Photo's from todays chase near Woodbine, KS photo's have been sent to nws awesome structure. Link to comment Share on other sites More sharing options...
Amped Posted June 20, 2011 Share Posted June 20, 2011 60 as of year 2000. I bet cows out number people there. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2011 Share Posted June 20, 2011 I wonder if people still think that a few tornadoes in northern OK tomorrow is outrageous... GFS isn't too good with thermo profiles. The NAM shows 90/65 in nrn OK... no tornadoes with those LCLs (unless you mean landspout tornadoes). Besides, the shear isn't really that good... there's an awkward back-veer-back in the mid levels. And if the NAM is right, you'd be lucky to get 30 degrees of turning between sfc and H5. Pretty bad. I'd be very surprised to see a legit tornado tomorrow in OK. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted June 20, 2011 Share Posted June 20, 2011 Today was one of the funnest chase days of my life. Went down to McCook and wasn't disappointed. Pictures coming. Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 Shear more perpendicular to the boundary down that way too. Can't sleep on it. Not really. Across nrn OK there's about 20-30° between the boundary and the shear vectors on the GFS. Link to comment Share on other sites More sharing options...
SluggerWx Posted June 20, 2011 Share Posted June 20, 2011 Sort of funny - at first glance, without knowing anything else other than a glance at radar, you would think "wow look at all those tornado warned cells" But then you see - there are no tornado warnings! Also interesting that said warnings with congo line decreased as congo line INCREASED it's distance from the nearest RADAR. I'd bet these things are still stronger than what we're seeing on RADAR. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2011 Share Posted June 20, 2011 Also interesting that said warnings with congo line decreased as congo line INCREASED it's distance from the nearest RADAR. I'd bet these things are still stronger than what we're seeing on RADAR. Nah, those storms are probably elevated. The boundary layer continues to cool, and the EML is being advected to the north, so if anything these cells will become more elevated with time. Nice hailers though, and interesting to watch on radar. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted June 20, 2011 Author Share Posted June 20, 2011 Also a thing to note about further east too along the warm front...upper level winds are not strong at all so HP structures would be a good bet since venting precip looks like a problem. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted June 20, 2011 Share Posted June 20, 2011 Link to comment Share on other sites More sharing options...
OKpowdah Posted June 20, 2011 Share Posted June 20, 2011 GFS isn't too good with thermo profiles. The NAM shows 90/65 in nrn OK... no tornadoes with those LCLs (unless you mean landspout tornadoes). Besides, the shear isn't really that good... there's an awkward back-veer-back in the mid levels. And if the NAM is right, you'd be lucky to get 30 degrees of turning between sfc and H5. Pretty bad. I'd be very surprised to see a legit tornado tomorrow in OK. near surface dps are probably a little overdone, but LCLs still wouldn't be high enough to categorically rule out tornadoes. Also again, the trend continues to deepen the base of the trough, increasing vorticity advection and decreasing temperatures aloft. The cap on that sounding is definitely manageable. 700mb temps are ~10-12C. FWIW, the NAM has not been good with convection down here for a while. Anyway, still showing helicity of 150-200J/kg, increasing above 300 as the LLJ kicks in after 00z. Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 I wonder if people still think that a few tornadoes in northern OK tomorrow is outrageous... Let's practice some meteorology here. GFS = notoriously runs high on dewpoints. Notoriously. If you can identify where in the Sam Hell you are going to get 75°F+ dewpoints in Oklahoma tomorrow then be my guest. Hint: you won't find anywhere. Even down to Corpus Christi and Brownsville you've got shallow moisture, with truly rich moisture not even reaching 850mb. And if that airmass got advected into Oklahoma tomorrow, the strong boundary layer winds will immediately mix out those mid-70 dewpoints, which, to reiterate, are down on the Gulf Coast right now. Operational meteorology is so much more than seeing a synoptic pattern and then looking for any piece of evidence to support your preconceived notions. Common sense is required. And if you actually look at some current sfc and upper air data, you will not see a tornado threat being all that conceivable in Oklahoma tomorrow. And given that I'm usually the one who plays bullish w/r/t tornado threats, that's saying something. Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2011 Share Posted June 20, 2011 Still an impressive hook on that cell in southern neb. It's been going forever. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted June 20, 2011 Share Posted June 20, 2011 Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 Awesome structure shots! Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2011 Share Posted June 20, 2011 near surface dps are probably a little overdone, but LCLs still wouldn't be high enough to categorically rule out tornadoes. Also again, the trend continues to deepen the base of the trough, increasing vorticity advection and decreasing temperatures aloft. The cap on that sounding is definitely manageable. 700mb temps are ~10-12C. FWIW, the NAM has not been good with convection down here for a while. Anyway, still showing helicity of 150-200J/kg, increasing above 300 as the LLJ kicks in after 00z. Empirically, I've set a threshold of 15F T/Td spread as a boundary where LCLs become unmanageable for tornadoes. You can still get a few weak tornadoes if it's close and other parameters are strong enough (see KS today; Dallas 5/24/11), but otherwise high LCLs trump everything other thing out there. Assume a conservative estimate of a 90F high tomorrow. If Td's are 75F tomorrow, we can talk about a few tornadoes. But really, with a June EML in a year that's already above average in terms of EML's (going back all the way to April)... with the strong June Oklahoma sun ensuring deep mixing... with a drought ongoing just to the south and west... how are you going to get 75F? Anyway, sorry for beating a dead horse. I guess the purpose of this post was mostly to share my 15F empirical rule, haha. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2011 Share Posted June 20, 2011 has there ever been a 0-1 km EHI of 19 before? I can't recall any instance. Link to comment Share on other sites More sharing options...
OKpowdah Posted June 20, 2011 Share Posted June 20, 2011 Let's practice some meteorology here. GFS = notoriously runs high on dewpoints. Notoriously. If you can identify where in the Sam Hell you are going to get 75°F+ dewpoints in Oklahoma tomorrow then be my guest. Hint: you won't find anywhere. Even down to Corpus Christi and Brownsville you've got shallow moisture, with truly rich moisture not even reaching 850mb. And if that airmass got advected into Oklahoma tomorrow, the strong boundary layer winds will immediately mix out those mid-70 dewpoints, which, to reiterate, are down on the Gulf Coast right now. Operational meteorology is so much more than seeing a synoptic pattern and then looking for any piece of evidence to support your preconceived notions. Common sense is required. And if you actually look at some current sfc and upper air data, you will not see a tornado threat being all that conceivable in Oklahoma tomorrow. And given that I'm usually the one who plays bullish w/r/t tornado threats, that's saying something. lol I know the GFS bias, and I already mentioned it. I know you're about 50 times more experienced with severe weather forecasting, but your condescension is getting annoying. I'm saying the threat for one or two tornadoes in northern OK (like N and E of Enid), which is entirely conceivable. Link to comment Share on other sites More sharing options...
OceanStWx Posted June 20, 2011 Share Posted June 20, 2011 Not really. Across nrn OK there's about 20-30° between the boundary and the shear vectors on the GFS. I was just looking at that myself, I expected the shear vectors to be a little more veered with the jet a little more swly aloft but clearly they aren't. While I'm not advocating venturing to nrn Oklahoma tomorrow, I am using it as an example to not get too focus on the "bullseye" up the Missouri Valley. I would not be surprised to see some nice storms around the Manhattan area again. And of course the potential further down the warm front is great, if (stop me if you've heard this before) overnight convection doesn't mess it up. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2011 Share Posted June 20, 2011 has there ever been a 0-1 km EHI of 19 before? I can't recall any instance. Bangladesh? Link to comment Share on other sites More sharing options...
OKpowdah Posted June 20, 2011 Share Posted June 20, 2011 Empirically, I've set a threshold of 15F T/Td spread as a boundary where LCLs become unmanageable for tornadoes. You can still get a few weak tornadoes if it's close and other parameters are strong enough (see KS today; Dallas 5/24/11), but otherwise high LCLs trump everything other thing out there. Assume a conservative estimate of a 90F high tomorrow. If Td's are 75F tomorrow, we can talk about a few tornadoes. But really, with a June EML in a year that's already above average in terms of EML's (going back all the way to April)... with the strong June Oklahoma sun ensuring deep mixing... with a drought ongoing just to the south and west... how are you going to get 75F? Anyway, sorry for beating a dead horse. I guess the purpose of this post was mostly to share my 15F empirical rule, haha. haha thanks, I'll keep that rule in mind. I just know that high based tornadoes aren't unheard of Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2011 Share Posted June 20, 2011 haha thanks, I'll keep that rule in mind. I just know that high based tornadoes aren't unheard of They aren't... the random ND F4 on 7/.../04 (specific date escapes me) was one which violated the empirical rule. So it's not going to work all the time. But more often than not, high-based tornadoes are landspoutish and nonsupercellular in nature, not actually "legit". The High Plains may also tolerate high bases better, but I can only speculate on that. 99 times out of 100 though, cold RFDs in high LCL supercells just do not work out. Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 lol I know the GFS bias, and I already mentioned it. I know you're about 50 times more experienced with severe weather forecasting, but your condescension is getting annoying. I'm saying the threat for one or two tornadoes in northern OK (like N and E of Enid), which is entirely conceivable. I'm sorry if it comes off as condescending, but you've pretty much been the one telling me what convective temperature is, dropping one-liners like "who thinks it can't happen now?", who has told me that an overall 1°C difference in H7 temp from 13-16 to 12-14 made a big difference, who has made up trends in the sfc low development, in moisture advection, etc., etc., etc. Essentially what amounts to, to paraphrase Sarah Palin, "GOTCHA!" meteorological debate. Sorry if I'm a little peeved at this point. I apologize to the other thread participants as I've been trying lately to offer insight without much fuss/fire/attitude. The rest of this part of this conversation can be taken to PM. Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 They aren't... the random ND F4 on 7/.../04 (specific date escapes me) was one which violated the empirical rule. So it's not going to work all the time. But more often than not, high-based tornadoes are landspoutish in nature, not actually "legit". The High Plains may also tolerate high bases better, but I can only speculate on that. 99 times out of 100 though, cold RFDs in high LCL supercells just do not work out. 7/18/04. And fwiw, I typically use about 20°F at the sfc, but the idea is the same. Link to comment Share on other sites More sharing options...
cyclone77 Posted June 20, 2011 Share Posted June 20, 2011 Regarding the warm front tomorrow I think northeast Illinois and points east through northern Indiana into western/northwest Ohio look pretty good. Very nice forecast soundings from the NAM in those areas. Further west in northwest Illinois and eastern Iowa we'll be situated in between the favored areas to the east and the obvious favored area to the west in the Plains. Forecast soundings in this area look pretty lame IMO. Northern Indiana could be very nice if they can destabilize as expected. If I were chasing tomorrow I'd play the percentage game and pick the western target somewhere west of Lincoln Nebraska. Link to comment Share on other sites More sharing options...
natecast Posted June 20, 2011 Share Posted June 20, 2011 Empirically, I've set a threshold of 15F T/Td spread as a boundary where LCLs become unmanageable for tornadoes. You can still get a few weak tornadoes if it's close and other parameters are strong enough (see KS today; Dallas 5/24/11), but otherwise high LCLs trump everything other thing out there. Assume a conservative estimate of a 90F high tomorrow. If Td's are 75F tomorrow, we can talk about a few tornadoes. But really, with a June EML in a year that's already above average in terms of EML's (going back all the way to April)... with the strong June Oklahoma sun ensuring deep mixing... with a drought ongoing just to the south and west... how are you going to get 75F? Anyway, sorry for beating a dead horse. I guess the purpose of this post was mostly to share my 15F empirical rule, haha. This is a topic for another thread, but how do supercells in the high plains of WY/CO seem to produce under very marginal conditions? I know there have been greater T/Td spreads up there than 15F. Sorry to get off topic there. To get back on topic, with the large T/Td spread in OK tomorrow evening, and slightly cooler mid-level temps being forecasted by the newest GFS, I think an MCS with damaging wind seems like a good bet. I will not comment on tornadoes. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted June 20, 2011 Share Posted June 20, 2011 Awesome structure shots! Thanks! It was an incredibly fun chase. Lots of neat storms--that Mccook cell was the gift that kept on giving. Storm motions today were incredibly slow. That LP supercell off in the distance at sunset capped it off. It was tremendous watching the cells along the flanking line just line up. Probably one of the longest I had seen before. A couple more. Saw a few gustnadoes too. All in all more than enough excitement. I don't need to see tornadoes to say a chase was successful. Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 Regarding the warm front tomorrow I think northeast Illinois and points east through northern Indiana into western/northwest Ohio look pretty good. Very nice forecast soundings from the NAM in those areas. Further west in northwest Illinois and eastern Iowa we'll be situated in between the favored areas to the east and the obvious favored area to the west in the Plains. Forecast soundings in this area look pretty lame IMO. Northern Indiana could be very nice if they can destabilize as expected. If I were chasing tomorrow I'd play the percentage game and pick the western target somewhere west of Lincoln Nebraska. Big question will be possible (probable?) morning MCS, subsidence behind it, and destabilization behind it. If we get sufficient destabilization and lift, well that wouldn't be good for Chicago metro... Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2011 Share Posted June 20, 2011 Thanks! It was an incredibly fun chase. Lots of neat storms--that Mccook cell was the gift that kept on giving. Storm motions today were incredibly slow. That LP supercell off in the distance at sunset capped it off. It was tremendous watching the cells along the flanking line just line up. Probably one of the longest I had seen before. A couple more. Saw a few gustnadoes too. All in all more than enough excitement. I don't need to see tornadoes to say a chase was successful. I love that area for chasing, SW NE/NE CO/NW KS. And you and I think the same way. Link to comment Share on other sites More sharing options...
Ed Lizard Posted June 20, 2011 Share Posted June 20, 2011 Thanks! It was an incredibly fun chase. Lots of neat storms--that Mccook cell was the gift that kept on giving. Storm motions today were incredibly slow. That LP supercell off in the distance at sunset capped it off. It was tremendous watching the cells along the flanking line just line up. Probably one of the longest I had seen before. A couple more. Saw a few gustnadoes too. All in all more than enough excitement. I don't need to see tornadoes to say a chase was successful. Nice. Trying to get a lightning shot? I've heard of just leaving the shutter open for a few seconds and hoping to get lucky, to actually snap one would take some luck. Link to comment Share on other sites More sharing options...
Stebo Posted June 20, 2011 Share Posted June 20, 2011 one of the most amazing and beautiful radar images/loops I've ever seen. 5 supercells in a east-west line going up on the LLJ. The three still in NE went up and took hard right turns, just wow. Also three of them are over 60kft tall. This picture is excellent, like someone said it's almost like a time lapse of an evolution of a supercell as it translates ESE. Link to comment Share on other sites More sharing options...
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