ZackH Posted April 25, 2014 Share Posted April 25, 2014 Yeah. Certainly a negative trend, and it's inside of 48 hrs now. Really starting to get the feeling that choosing the correct storm in a string of pearls across NE/N KS between 18-22z Sunday will determine whether a chaser has any real success this weekend. At least, that's becoming the most probable scenario. Saturday is likely to be one of those very frustrating exercises in knowing a daytime cap bust is more likely than not, but "having" to go out anyway. lol.... whoops you already posted about it Link to comment Share on other sites More sharing options...
ZackH Posted April 25, 2014 Share Posted April 25, 2014 I think I'm the only one still optimistic about Saturday... the NAM just looks weird for Saturday and I think the GFS gives us a small window for a show. Of course, Brett and I work well together... he's the eternal pessimist and I'm the eternal optimist. I usually only get pessimistic once the chase begins. I just knew we were going to fail on both the Rozel and Wayne days... got frustrated early and then bam. Link to comment Share on other sites More sharing options...
wxtrackercody Posted April 25, 2014 Share Posted April 25, 2014 Gabe Garfield @WxGabe 1hSoundings at CRP & BRO show mean mixing ratios from 14.5 - 15.5 g/kg and ~150 mb deep - substantially higher than forecast. Link to comment Share on other sites More sharing options...
Msalgado Posted April 25, 2014 Share Posted April 25, 2014 I think I'm the only one still optimistic about Saturday... the NAM just looks weird for Saturday and I think the GFS gives us a small window for a show. Of course, Brett and I work well together... he's the eternal pessimist and I'm the eternal optimist. I usually only get pessimistic once the chase begins. I just knew we were going to fail on both the Rozel and Wayne days... got frustrated early and then bam. I'm optimistic but that's probably wishful thinking on my end now that I actually have time to drive out there. That and I don't know this a quarter as well as all of you. Link to comment Share on other sites More sharing options...
rockchalk83 Posted April 25, 2014 Share Posted April 25, 2014 Gabe Garfield @WxGabe 1h Soundings at CRP & BRO show mean mixing ratios from 14.5 - 15.5 g/kg and ~150 mb deep - substantially higher than forecast. So for those who aren't familiar with that...does that indicate a more buoyant atmosphere? Link to comment Share on other sites More sharing options...
wxtrackercody Posted April 25, 2014 Share Posted April 25, 2014 So for those who aren't familiar with that...does that indicate a more buoyant atmosphere? Yes, it indicates that the models are seriously underdoing moisture return for the time being. Link to comment Share on other sites More sharing options...
LocoAko Posted April 25, 2014 Share Posted April 25, 2014 Yes, it indicates that the models are seriously underdoing moisture return for the time being. Hey, combined with what's happened the last few events concerning dewpoints, maybe if that moisture makes it up here we'll actually squeak out the [still meh] modeled dewpoints. Link to comment Share on other sites More sharing options...
OKpowdah Posted April 25, 2014 Share Posted April 25, 2014 Forgetting the chaser perspective for a moment, we probably need to start talking more seriously about the implications of a solid nocturnal outbreak Saturday night over KS and OK Link to comment Share on other sites More sharing options...
AgeeWx Posted April 25, 2014 Share Posted April 25, 2014 Forgetting the chaser perspective for a moment, we probably need to start talking more seriously about the implications of a solid nocturnal outbreak Saturday night over KS and OK Which both the NAM and GFS have been implicating for some time now. IF moisture ends up being more robust than forecast, once the boundary layer decouples and the LLNJ kicks in, watch out. 850s are screaming Sunday morning. Link to comment Share on other sites More sharing options...
AgeeWx Posted April 25, 2014 Share Posted April 25, 2014 The SFC low looks like it occludes (or starts to) sometime between 03Z and 06Z Sunday allowing for a secondary surge of moisture underneath the better jet dynamics and a relatively dry plume of air at 700mb. Link to comment Share on other sites More sharing options...
1900hurricane Posted April 25, 2014 Share Posted April 25, 2014 Can confirm a soupy evening here in the southern half of Texas. The NWS has me in College Station getting down to 62*F tonight, but with us sitting with a dewpoint of 68*F right now, I don't think we'll make it. There's a pretty sharp moisture gradient between here and Waco right now, so it'll be interesting to see how much the moisture advances overnight. Sent from my iPhone Link to comment Share on other sites More sharing options...
Quincy Posted April 25, 2014 Share Posted April 25, 2014 I'm not sure how the RGEM handles convection, but it shows precip popping up by 21z Saturday in Texas ahead of the dryline and northward into Oklahoma by 00z. The kinematic support (all models) really ramps up overnight, but hopefully for the sake of chasers and the public alike we don't see nocturnal tornadic activity. Link to comment Share on other sites More sharing options...
Stebo Posted April 25, 2014 Share Posted April 25, 2014 Forgetting the chaser perspective for a moment, we probably need to start talking more seriously about the implications of a solid nocturnal outbreak Saturday night over KS and OK If there is any delay in decoupling of the atmosphere after sunset, things could be very ugly for OK and KS. I completely agree with your concerns, a system this strong will have the kinematics to overcome nocturnal cooling. Link to comment Share on other sites More sharing options...
brettjrob Posted April 25, 2014 Share Posted April 25, 2014 Plains climatology strongly disfavors nocturnal outbreaks, particularly if you're counting on initiation after sunset (as opposed to pre-existing supercells continuing to fight off CINH through their internal VPPGF). Of course there exceptions, and I agree that Saturday has an elevated risk at being an exception when compared to most dryline days. I'm not sure how the RGEM handles convection, but it shows precip popping up by 21z Saturday in Texas ahead of the dryline and northward into Oklahoma by 00z.The kinematic support (all models) really ramps up overnight, but hopefully for the sake of chasers and the public alike we don't see nocturnal tornadic activity. That is definitely noteworthy and good news. I've watched the RGEM a lot so far this spring, and it's outperformed both NCEP models on CI for at least a couple "events." Link to comment Share on other sites More sharing options...
Stebo Posted April 25, 2014 Share Posted April 25, 2014 Plains climatology strongly disfavors nocturnal outbreaks, particularly if you're counting on initiation after sunset (as opposed to pre-existing supercells continuing to fight off CINH through their internal VPPGF). Of course there exceptions, and I agree that Saturday has an elevated risk at being an exception when compared to most dryline days. That is definitely noteworthy and good news. I've watched the RGEM a lot so far this spring, and it's outperformed both NCEP models on CI for at least a couple "events." The difference this time compared to most other Plains events is we are dealing with an extremely strong system that is expected to be sub 985mb. There aren't many events in the Plains with systems this strong. Link to comment Share on other sites More sharing options...
natecast Posted April 25, 2014 Share Posted April 25, 2014 Plains climatology strongly disfavors nocturnal outbreaks, particularly if you're counting on initiation after sunset (as opposed to pre-existing supercells continuing to fight off CINH through their internal VPPGF). Of course there exceptions, and I agree that Saturday has an elevated risk at being an exception when compared to most dryline days. Beat me to the punch regarding Plains nighttime tornadoes. I was going over a chart earlier showing diurnal distribution of tornadoes in OKC, and there are so few late night tornadoes that have occurred. Only 17 of the 154 Oklahoma City area tornadoes since 1890 have occurred between 11:00PM and 7:00AM. That being said, the strength of the incoming trough and associated low-level response raises eyebrows about the possibility of an event that goes against the grain. Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 Ehh, I'm not sold on an overnight tornado threat Saturday night. Yeah, the low is very strong. But for an overnight threat, you really want as much moisture in the BL as possible to try and keep neutral BL stability. I just don't see that on the GFS or NAM right now. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2014 Share Posted April 25, 2014 Ehh, I'm not sold on an overnight tornado threat Saturday night. Yeah, the low is very strong. But for an overnight threat, you really want as much moisture in the BL as possible to try and keep neutral BL stability. I just don't see that on the GFS or NAM right now. what are your thoughts on sunday currently Tony? Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 what are your thoughts on sunday currently Tony? It depends on trough evolution. I like the NE/KS/MO quasi-cold-core area to start. But if the flow remains zonal enough for the Arklatex, it has enormous potential down there. I think convective feedback is still negatively impacting the GFS. I have no faith in the NAM at this range, but if its trough evolution were to work out, there would likely be a major tornado outbreak down at that end of the system. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2014 Share Posted April 25, 2014 It depends on trough evolution. I like the NE/KS/MO quasi-cold-core area to start. But if the flow remains zonal enough for the Arklatex, it has enormous potential down there. I think convective feedback is still negatively impacting the GFS. I have no faith in the NAM at this range, but if its trough evolution were to work out, there would likely be a major tornado outbreak down at that end of the system. In Southern AR/NE TX/SE OK area? Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 In Southern AR/NE TX/SE OK area? Yes. Ft. Smith/McAlester down to Shreveport/Tyler. Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 It depends on trough evolution. I like the NE/KS/MO quasi-cold-core area to start. But if the flow remains zonal enough for the Arklatex, it has enormous potential down there. I think convective feedback is still negatively impacting the GFS. I have no faith in the NAM at this range, but if its trough evolution were to work out, there would likely be a major tornado outbreak down at that end of the system. Taking a closer look at that cold-core region, I like it less and less. It's veer-back-veer from the start and it only gets worse with time. It's probably Arklatex or bust. Link to comment Share on other sites More sharing options...
natecast Posted April 25, 2014 Share Posted April 25, 2014 I'm skeptical of nighttime tornadoes in OK/KS late Saturday and early Sunday morning like Brett and Tony, but an interesting snippet at the end of the SPC Day 2 just issued: "AS LARGE-SCALE ASCENT STRENGTHENS SUBSTANTIALLY EARLY SUN...ELEVATEDTSTMS WILL INCREASE IN COVERAGE FROM THE MID-MO VALLEY TO THE SUNPLAINS WITH STEEP LAPSE RATES SUPPORTING A LARGE HAIL THREAT. SOMEOF THIS ACTIVITY MAY BECOME SURFACE-BASED ACROSS THE SRNPLAINS...WHERE SURFACE DEW POINTS INCREASE INTO THE MIDDLE60S...SUPPORTING POTENTIAL FOR ALL SEVERE HAZARDS." Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2014 Share Posted April 25, 2014 Not as enthused about the Sunday setup as the past few days, but Nebraska is still looking okay. Never was a fan of the early initiation type setups, but it isn't a deal breaker. Shear is pretty nice over parts of Nebraska by early afternoon on the nose of the better mid-level speed max. Instability is pretty meager for much of the warm sector unfortunately, but I'm hoping a few areas can destabilize better than some of the models have forecast. For Sunday the best play for tors is probably up in NE or far northern KS at this point, unless something changes again. Link to comment Share on other sites More sharing options...
David Reimer Posted April 25, 2014 Share Posted April 25, 2014 I'm skeptical of nighttime tornadoes in OK/KS late Saturday and early Sunday morning like Brett and Tony, but an interesting snippet at the end of the SPC Day 2 just issued: "AS LARGE-SCALE ASCENT STRENGTHENS SUBSTANTIALLY EARLY SUN...ELEVATED TSTMS WILL INCREASE IN COVERAGE FROM THE MID-MO VALLEY TO THE SUN PLAINS WITH STEEP LAPSE RATES SUPPORTING A LARGE HAIL THREAT. SOME OF THIS ACTIVITY MAY BECOME SURFACE-BASED ACROSS THE SRN PLAINS...WHERE SURFACE DEW POINTS INCREASE INTO THE MIDDLE 60S...SUPPORTING POTENTIAL FOR ALL SEVERE HAZARDS." It's something to obviously watch. FWIW the 4-KM NAM does go bonkers with a cell between Lawton and Chickasha between 03Z-06Z Sunday with impressive updraft helicity values. I don't trust the 12KM version even within six hours of an event, but I will pay more attention to the 4-KM version. At this point it's just one of several possible scenarios to watch for and hopefully discount or become more confident on as we continue into Friday. Link to comment Share on other sites More sharing options...
jcwxguy Posted April 25, 2014 Share Posted April 25, 2014 i work 3-11 saturday, but off sunday, so i may be able to chase locally ~50 miles Link to comment Share on other sites More sharing options...
brettjrob Posted April 25, 2014 Share Posted April 25, 2014 Taking a closer look at that cold-core region, I like it less and less. It's veer-back-veer from the start and it only gets worse with time. It's probably Arklatex or bust. If that's the case, I think the whole system's a wrap for chasers, at least those unwiling to bring chainsaws to hack their way out toward your area. I do fear you may be right because of how incredibly backed the upper flow is from I-70 northward, though I'm holding out some hope. There have been meridional, VBV Plains days that I wrote off and then they way overperformed (see: 5/24/10, 6/20/11), but the 500 mb pattern looks even nastier Sunday than those. More importantly, they also had much richer, preexisting moisture and associated high CAPE. Maybe the most realistic analog for optimism in NE/KS is 2006-04-06, which has been brought up in this thread already I believe. Not a great day, but at least one cyclic storm near the ULL in N KS. Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 If that's the case, I think the whole system's a wrap for chasers, at least those unwiling to bring chainsaws to hack their way out toward your area. I do fear you may be right because of how incredibly backed the upper flow is from I-70 northward, though I'm holding out some hope. There have been meridional, VBV Plains days that I wrote off and then they way overperformed (see: 5/24/10, 6/20/11), but the 500 mb pattern looks even nastier Sunday than those. More importantly, they also had much richer, preexisting moisture and associated high CAPE. Maybe the most realistic analog for optimism in NE/KS is 2006-04-06, which has been brought up in this thread already I believe. Not a great day, but at least one cyclic storm near the ULL in N KS. Yeah if I may be rather blunt I think this system is a wrap for the plains chasers tornado wise, and probably not great structure wise either since most storms outside the Ouachitas will be VBV contaminated or nocturnal. Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2014 Share Posted April 25, 2014 Now for Dixie, we've got a whole different story likely developing on the tornado front for those who want to take a walk in the woods. Link to comment Share on other sites More sharing options...
thewxmann Posted April 25, 2014 Share Posted April 25, 2014 Yeah if I may be rather blunt I think this system is a wrap for the plains chasers tornado wise, and probably not great structure wise either since most storms outside the Ouachitas will be VBV contaminated for nocturnal. I agree. Should've never bought those plane tickets to come out to the Plains... no refunds Link to comment Share on other sites More sharing options...
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