2019-05-27 EVENT: CO/NE/WY/IA/IL/IN/MI/OH

Jesse Risley

Staff member
Apr 12, 2006
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Macomb, IL
www.tornadoguys.com
Two plays today within the broader southwest flow aloft, as the main upper low works into the lower Great Basin region, and this is progged to push into the four corners region by late today. Further west, it looks like a potent H5 perturbation will begin to overspread the Rockies and eastern Piedmont regions by late afternoon. Looking at a current morning surface map, moisture is pooling into the upslope regions, longitudinally, across the Colorado Piedmont and Sand Hills region. The usual zone of vorticity and convergence should initiate storms across NE CO and SE WY by mid to late afternoon. It should be noted that some models have been depicting moisture mixing out at the lower levels. Nevertheless, ample shear and moisture should exist to support some robust updrafts as storms work ENE into W NE. Progged soundings do show favorable LCLs, MLCAPE profiles and marginal streamwise vorticity to facilitate a few supercells with a tornado or two not out of the question; storms in the southern portion of the area of greatest risk, namely NE CO and far SW NE, will have the more favorable proximity to the better mid-level flow. In addition, favorable looking CAPE values within the -10 to -30° C layer and formidable 700-500 mb lapse rates would suggest there will be some higher end severe hail reports too.

Of greater concern is the low pressure system in eastern IA and warm front progged to extent ESE into NC IL and IN. Ongoing convection will likely have an impact on the eventual placement of the warm front, and residual OFBs will be exist across the region as well. The atmosphere is forecast to destabilize by late afternoon, as storms should initial in the warm sector across MO and E IA and propagate eastward in N IL. Discrete supercells appear to initially be the dominant storm mode, and all modes of SVR weather are possible, including a heightened risk of tornadoes where storms are able to interact with the surface warm front or residual boundaries, given very magnanimous 0-1 km SRH profiles around 200-300 m2/s2 and amble instability parameters. PW values are quite large, which lead to some concerns with the evolution of HP supercells, given SR anvil level winds, and visibility issues. With time, convection looks to morph into more of a QLCS mode as storms gyrate eastward towards SW MI, N IN and eventually NW OH, where wind damage and embedded mesovortices become the dominant threats. I would expect a few strong tornado reports are likely today with initial discrete convection, assuming storms are able to interact and maintain themselves commensurate with residual boundaries and/or the surface warm front, and also assuming that adequate destablization materializes in the wake of earlier convective activity approaching from the WSW.
 
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Jun 16, 2015
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Oklahoma City, OK
quincyvagell.com
A conditional, yet potentially high-reward target is along the dryline from Kansas to the eastern panhandle vicinity. While most models don’t show convective initiation, the HRRR shows temperatures within 2-3F of convective temperature breach around 00z. The background environment is very favorable with strong/extreme instability (3000-5000 J/kg SBCAPE), 40-50 knots of deep layer shear oriented close to perpendicular to the dryline and large scale forcing just glancing the region by early evening.

There are some similarities to 5/17/19, including with model convective signals. A few NCAR/HREF/HopWRF ensemble members do hint at convection, but none of them show any sustained, robust updrafts.

It’s one of those setups where you just give it a shot, especially if you can’t make it to the other two more obvious targets.

Given rich low-level moisture and am extremely favorable CAPE/shear environment early this evening, if there is a storm, it would not be surprising if it produced a significant tornado.
 
Jul 5, 2009
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Newtown, Pennsylvania
Tough call today. Agree with Quincy, a SW KS play is interesting. 15Z RAP for OOZ hints at a dryline bulge just south of there. Same model run produces a TOR sounding in northeast CO near the WY/CO/NEB border region but 61 over 57?!? I know crazy stuff happens in CO and that results in some nice LCLs but man those are some cool temps for a chase target... Crazy stuff happens in SW KS too, I can just picture some line supercell cruising along down there later... But starting in GLD today, hard to justify the long drive south for a conditional play, if I was already there I might feel differently... Still undecided at the moment.

EDIT: Going with CO, probably starting around Fort Morgan. Dryline play in KS seems too uncertain for my liking. Dryline relatively diffuse there. Position very different on RAP vs NAM/NAM 3k. Surface obs would corroborate the NAM and SPC 16:30 outlook seems to buy that more eastward position as well. SPC also added 5% TOR to TX PH but I am not focusing any analysis time on that area, just too out of range relative to the CO target and don’t like the road network in parts of that region either.
 
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Mar 3, 2012
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Hillsdale, MI
I almost decided to leave from the Michigan/Ohio/Indiana border to get in on the Illinois play. I ended up not going and decided to let things come to me. Ironically, I am at my grandfather's house that took a direct hit to the two '65 Palm Sunday tornadoes that followed the same path the two lead supercells in Indiana are taking. He has told me the story many times, running to check on his neighbors and hearing the second one coming and having to run back home just in time. It doesn't look like we'll get anything like that, but I have been contemplating moving west towards those storms for the last hour or so.

What is frustrating is that I told a friend in Indiana that I wanted to target Warsaw after I decided Indiana was going to be better than i initially expected and stayed home. I knew I could get there in about 2 hours. Of course I didn't go and now there is a PDS Warning just south of Warsaw, with a 2 mile wide debris ball on radar.

I have seen zero tornadoes in my lifetime, only dreamt about that event happening hundreds of times. This is the third time that me erring on the side of caution and bailing or not going to my target has cost me a shot at it. A chaser I talked to today told me that I won't see one sitting on my comfy couch. I should have listened lol.
 
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