Superstorm93 Posted April 26, 2014 Share Posted April 26, 2014 Just curious, something I might want to post on FB, is there a website for 4 km NAM forecast skew-Ts? Not that I know of...would be very helpful http://weather.cod.edu/forecast/ Their label for the '4km NAM' is actually the SPC-WRF --------- 15z SREF now has two areas of extreme tornado potential tomorrow evening: Link to comment Share on other sites More sharing options...
andyhb Posted April 26, 2014 Author Share Posted April 26, 2014 Is that a spot of a level above 75 on that in AR? Link to comment Share on other sites More sharing options...
Disc Posted April 26, 2014 Share Posted April 26, 2014 ------ 15z SREF now has two areas of extreme tornado potential tomorrow evening: SREF_prob_combined_sigtor__f033.gif Although this product has been redone and while its easier to get the higher numbers I think this is the most bullish I've seen this product since its upgrade. Very impressive. Link to comment Share on other sites More sharing options...
Hoosier Posted April 26, 2014 Share Posted April 26, 2014 That almost looks like a tiny 90% contour trying to show up on that SREF image above. Don't recall seeing that before. Link to comment Share on other sites More sharing options...
nwburbschaser Posted April 26, 2014 Share Posted April 26, 2014 Is that a spot of a level above 75 on that in AR? It definitely looks that way to me. Link to comment Share on other sites More sharing options...
Ed Lizard Posted April 26, 2014 Share Posted April 26, 2014 http://weather.cod.edu/forecast/ I don't see how to generate a skew-T off that. But I have bookmarked the site. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 26, 2014 Share Posted April 26, 2014 That almost looks like a tiny 90% contour trying to show up on that SREF image above. Don't recall seeing that before. Not all that surprising given that instability, shear, helicity, LCL heights, and convective precip should all line up there. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 26, 2014 Share Posted April 26, 2014 Is that a spot of a level above 75 on that in AR? Wow...looks like it. EDIT: Ed, I think this is what you may be looking for http://www.wxcaster.com/wrf_skewt_looper.htm If we can have a secondary develop over AR...forget about it Link to comment Share on other sites More sharing options...
Jim Marusak Posted April 26, 2014 Share Posted April 26, 2014 as well, time to watch that curly-q disturbance at 500 as it moves in from Arizona, as that is the key to this whole mess getting started tonight and tomorrow. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 26, 2014 Share Posted April 26, 2014 You got down there kind of early. You wanting to get in on some hailers tonight?Yea we did...several hours early.At this point I'm leaning against anything decent this evening. Link to comment Share on other sites More sharing options...
tornadotony Posted April 26, 2014 Share Posted April 26, 2014 Wow...looks like it. EDIT: Ed, I think this is what you may be looking for http://www.wxcaster.com/wrf_skewt_looper.htm If we can have a secondary develop over AR...forget about it SREF_prob_combined_sigtor__f057.gif Ugh. Link to comment Share on other sites More sharing options...
tornadotony Posted April 26, 2014 Share Posted April 26, 2014 The environment on the 18z NAM over MS and spreading into AL at 15z on Monday is insane. Just insane. With convection already ongoing, I would imagine we'd be off and running. It's conceivable that strong-violent tornadoes may be ongoing from 21z tomorrow afternoon all the way until predawn Tuesday morning. And after that, we have to tackle Tuesday. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 26, 2014 Share Posted April 26, 2014 The environment on the 18z NAM over MS and spreading into AL at 15z on Monday is insane. Just insane. With convection already ongoing, I would imagine we'd be off and running. It's conceivable that strong-violent tornadoes may be ongoing from 21z tomorrow afternoon all the way until predawn Tuesday morning. And after that, we have to tackle Tuesday. A lot of the forecast soundings try and stabilize the boundary layer tomorrow night, but not so much so that a well rooted supercell couldn't remain surface based. Link to comment Share on other sites More sharing options...
PSUBlizzicane2007 Posted April 26, 2014 Share Posted April 26, 2014 Wow...looks like it. EDIT: Ed, I think this is what you may be looking for http://www.wxcaster.com/wrf_skewt_looper.htm If we can have a secondary develop over AR...forget about it SREF_prob_combined_sigtor__f057.gif Looking at the forecasted Skew-Ts for KSRC is horrifying Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 26, 2014 Share Posted April 26, 2014 Whatever convection fires off tomorrow could actually lift north of the risk area for Monday... Link to comment Share on other sites More sharing options...
Disc Posted April 26, 2014 Share Posted April 26, 2014 FWIW almost all the severe parameters are maxed out or close to it on the 18z 4km NAM.. Fixed-layer STP is pushing 10 at points 0-3KM EHI is completely maxed out for several frames Supercell composite is also maxed out in several frames ..and the list goes on. Link to comment Share on other sites More sharing options...
BuffaloWeather Posted April 26, 2014 Share Posted April 26, 2014 FWIW almost all the severe parameters are maxed out or close to it on the 18z 4km NAM.. Fixed-layer STP is pushing 10 at points 0-3KM EHI is completely maxed out for several frames Supercell composite is also maxed out in several frames ..and the list goes on. Do you expect a high risk to come from the SPC for both Sunday and Monday? Link to comment Share on other sites More sharing options...
Torchageddon Posted April 26, 2014 Share Posted April 26, 2014 The 00z UKMET incidentally also shows the same vorticity lobe swinging around the base of the trough during the day Monday, resulting in the strengthening of the low-level jet. The GFS has slowly trended towards showing this subtle vorticity lobe, but still hasn't caught up with the ECMWF/UKMET camp. I suspect it will as we get closer to the event. Taking Sunday and Monday together, I think that this is the most substantial large-scale tornado outbreak threat that we have seen since 2011. This is definitely not a garden variety spring tornado setup we're dealing with here... I heard similar several days ago from Reed. So more widespread and numerous in terms of tornadoes than March 2, 2012 and April 14, 2012? If all these days together is what is being pointed at, then that makes sense. The environment on the 18z NAM over MS and spreading into AL at 15z on Monday is insane. Just insane. With convection already ongoing, I would imagine we'd be off and running. It's conceivable that strong-violent tornadoes may be ongoing from 21z tomorrow afternoon all the way until predawn Tuesday morning. And after that, we have to tackle Tuesday. The only nocturnal tornado outbreak that stands out to me is the Leap Day one just before March 2, 2012. However rare those are, what is unheard of is a tornado outbreak being continuous from one day into the other, at least not from the 2 worst outbreaks in history which I think had some minor incidents IIRC joining days. It would truly be insane if that did occur. About tomorrow, what is the earliest possible time for storms to initiate without previous convection that might turn up overnight? We haven't see a before noon initiation for a while. Link to comment Share on other sites More sharing options...
MCS_hunter Posted April 26, 2014 Share Posted April 26, 2014 About tomorrow, what is the earliest possible time for storms to initiate without previous convection that might turn up overnight? We haven't see a before noon initiation for a while. It hasn't been that long. On November 17, 2013, storms were going by about 10 am. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted April 26, 2014 Share Posted April 26, 2014 It hasn't been that long. On November 17, 2013, storms were going by about 10 am. Yep, Washington, Il tornado was rolling through around 11am Link to comment Share on other sites More sharing options...
OceanStWx Posted April 26, 2014 Share Posted April 26, 2014 About tomorrow, what is the earliest possible time for storms to initiate without previous convection that might turn up overnight? We haven't see a before noon initiation for a while. It's not that overnight convection could prevent initiation, it's that overnight convection will stabilize the atmosphere and narrow the threat area for tomorrow late afternoon/evening severe convection. Link to comment Share on other sites More sharing options...
Indystorm Posted April 26, 2014 Share Posted April 26, 2014 Do you expect a high risk to come from the SPC for both Sunday and Monday? I would not be at all surprised to see this be issued at some point for both days given the intensity of this system with parameters nearly off the charts. Link to comment Share on other sites More sharing options...
OUGrad05 Posted April 26, 2014 Share Posted April 26, 2014 It's not that overnight convection could prevent initiation, it's that overnight convection will stabilize the atmosphere and narrow the threat area for tomorrow late afternoon/evening severe convection. Yeah a whole lot depends on overnight convection. If no convection overnight we could see early initiation on the dryline which would push the moderate risk back to the west but doesn't do anything to minimize the issues Arkansas is going to face tomorrow. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 26, 2014 Share Posted April 26, 2014 I would not be at all surprised to see this be issued at some point for both days given the intensity of this system with parameters nearly off the charts. I agree, but you won't see a day 2 high risk because of the question regarding overnight evolution of convection. Link to comment Share on other sites More sharing options...
Indystorm Posted April 26, 2014 Share Posted April 26, 2014 I agree, but you won't see a day 2 high risk because of the question regarding overnight evolution of convection. Agree on this issue, but three moderates in a row is really something as well considering Tues. potential. Link to comment Share on other sites More sharing options...
Indystorm Posted April 26, 2014 Share Posted April 26, 2014 SLP down to 988 mb in se CO at present with mid 60 dews already up to the Red River per SPC meso page. Link to comment Share on other sites More sharing options...
CUmet Posted April 26, 2014 Share Posted April 26, 2014 I heard similar several days ago from Reed. So more widespread and numerous in terms of tornadoes than March 2, 2012 and April 14, 2012? If all these days together is what is being pointed at, then that makes sense. Actually Sunday and Monday as individual days may exceed the magnitude of the events you mentioned, both in numbers of significant/violent tornadoes and in terms of human impact given the higher population density of the areas affected. I don't think any of the upcoming individual days look quite as impressive as 4/27/11, but on the other hand we have several days to get through. Comparisons aside, it's a very dangerous setup over a lot of real estate. Link to comment Share on other sites More sharing options...
Jim Marusak Posted April 26, 2014 Share Posted April 26, 2014 one thing I am noticing on the 18Z NAM bufkit profiles, and yes I know it's the 18Z NAM to take it as a grain of salt. but if you look monday morning for areas like BNA, LIT, STL, MEM, etc; there's a ton of elevated cape (1500-2500 J/kg) that can spark off at a fairly reachable height between 800 and 900hpa. that's not exactly good comfort if you have all types of convection coming from the west, as gust fronts and other meso-boundaries can get to that height rather easily. Link to comment Share on other sites More sharing options...
Hoosier Posted April 26, 2014 Share Posted April 26, 2014 For reference...in relation to what was posted above... March 2, 2012 April 14, 2012 Link to comment Share on other sites More sharing options...
tornadotony Posted April 26, 2014 Share Posted April 26, 2014 one thing I am noticing on the 18Z NAM bufkit profiles, and yes I know it's the 18Z NAM to take it as a grain of salt. but if you look monday morning for areas like BNA, LIT, STL, MEM, etc; there's a ton of elevated cape (1500-2500 J/kg) that can spark off at a fairly reachable height between 800 and 900hpa. that's not exactly good comfort if you have all types of convection coming from the west, as gust fronts and other meso-boundaries can get to that height rather easily. The 0-1km SRH should allow for dynamic enhancement of updrafts through any shallow, weak stable layer and allow storms to become sfc-based. Link to comment Share on other sites More sharing options...
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