05/29/06 FCST: MN / IA / NE / KS / OK

Jul 23, 2004
Iowa City, IA
Chase target:
Pratt, KS.

Storm initiation 7 PM CDT.

Storms will fire along a cold front during the early evening hours, and the southern-most storm in the line will be the target. Severe storms, capable of 1" hail and winds to 70mph, will be possible during the early evening.

In short, the best moisture will be located just to the east of the UA support. The right entrance region of a 40kt H5 streak will lift through SWRN KS while a 30kt H7 wave develops in response to the UA divergence. The target location is just to the W of the axis of maximum instability with MLCAPE's of 2500J/kg. Slow cyclogenesis will occur in the OK panhandle along the CF while the front stalls out in SRN KS. After dark, a 30kt LLJ should sustain storms into the late evening.

- bill
As of right now, I think the setup today in Kansas will be pretty marginal. Directional shear is so so but the speed shear is terrible. I think the only thing going for the setup today is descent Td and high temps which will lead to extreme CAPE in the 3-4000 range. The result will be multicell storms producing very large hail (up to baseball size) and gusty downburst winds.



HIGH WIND THREAT: medium to high

I like the target being talked about currently [since MN is far away, I'm ignoring it :)]. I think tomorrow is very similar to the set up that was present east of GLD on Friday. If a good mesoscale accident occurs, might see another impressive supercell/cluster like on Friday. If things go as they usually do, probably won't see anything :) Keeping with my parallel to Friday, if I go out, I'll stick close to any surface boundaries that are out there, especially if any intersect (if there are any). Considering we don't have convection leaving behind boundaries nor a good synoptic low/frontal set up, I have my doubts about initiation.

Should storms fire AND there is good turning below cloud level should see some good updraft rotation, probably hail near golfball size and very windy storms. Storms should be slow to move at first until it precips enough to get the cold pool into action.

Should storms fire AND there is not turning below cloud base/crap shear, wouldn't be surprised to see only one or two cells and that's the end of the show. The reason I believe in the quick show is I think that the BL will be too deep and HOT for the cold pool to be good enough to initiate new cells. Still the storms would be capable of 1" hail and high winds.

If storms don't fire, enjoy the holiday! ENJOY!
I am thinking about heading to southern MN today for my first chase of the year, as there will certainly be plenty of instability, but shear certainly concerns me. Temperatures are extremely warm up here, with 90s probably common today and Tds well into the 60s. My preliminary target is going to be near Mankato, but I am going to re-evaluate everything later this morning. Maybe there will be a pooling of Tds somewhere in the area. Everything will probably merge together into a big messy MCS, but maybe there will be some good storms initially. Probably no tornadoes today, but still a chase opportunity.

Good luck to anyone that goes out today.

-Andy Hamm
Yesterday's problem was that we had the right ingredients but a mega cap. Today's problem is that the ingredients are screwed up and we have very little cap. High instabilities ahead of the CF with little in the way of shear looks like a big hail fest today. 0-3 km SRH ahead of the cold front is scrawny everywhere except northern MN (where it STRUGGLES to reach 250 m2/s2 ... there's also >200 0-3 km SRH in eastern Nebraska, I see, but this also looks to be behind the boundary ... 0-1 km SRH is even worse - I'd recommend not even bothering to pull it up). It's non-existent over Kansas from what I can tell at this point, except for behind the boundary where there's just all kinds of helicity. Too bad the instability/moisture isn't over Goodland today. Heading back to KC here ... may try to get some lightning shots. Hopefully we'll at least see rain.
As many of you have mentioned the threat doesn't look that great, but of course I'll be heading out anyway. Probably more of a local chase for me as I'll stay around northwest Iowa/southwest Minnesota for the most part. Instability is going to be very good in the area, I think what we'll need is for something to develop right on the cold front and try to get somewhat of an act together. I don't see that happening to well anyway, so probably just some monster towers to go with the large hail threat. Either way ya never know what could happen, so might as well take the chance and enjoy what show we can get.
Today is a very marginal day for tornadic storms. The 500 mb level winds are too low across eastern Kansas. Iowa and especially MN show better flow. The cap is high but should improve as 700 mb temps decrease. The cold front is along the SD/MN border and extends southwesterly through eastern NE and central KS. I do like the mid 60’s to low 70’s dewpoints streaming into MN with south-southeasterly winds in southcentral MN. Unfortunately, the 12Z NAM shows these winds all turning to the southwest as the front progresses except for SE KS and MO. I am currently in Mitchell, SD. I am checking more data but am considering blowing off this extremely marginal day. Tomorrow and Wednesday are looking better southwest Kansas and the Texas/Oklahoma panhandles. I’d hate be chasing junk in southern MN, then have to get down to SW Kansas

Bill Hark
Well, as today is our last chase day before we head back to the UK tomorrow, anything thundery will do us!! We're more than likely going to target Medicine Lodge - I like the backed flow on several of the models in that area, including the 40km ECMWF. This model also induces a small dryline punch to the south of the area late in the afternoon/early evening. Shear is not very good, but beggars can't be choosers!
I'll be heading out in about half an hour to get in position for the first two hours of intiation. After that, storm coverage/shear vector/weakening mid-level winds should promote a linear line. Current thinking is between 18z-20z, intially 0-6km shear vector isn't parallel and the mid-level flow is a bit stronger (though both are even mariginal to begin with.) Some localized areas of weak convergence might yield some intiation that can remain isolated at least for an hour or two and would be in a strongly unstable airmass. LCL's aren't terribly bad intially (1200m) but get upwards of 1400-1500m towards peak heating and probably higher due to mixing. The steep low level lapse rates & low level cape may enhance stretching potiental for a brief tornado but the overall tornadic threat is mitigated by many factors.

Leaving for: -Lewisville, MN-
Good luck to all who are out today!
Scott O.
Looks like the 4.5km WRF doesn't even form storms until dusk or later. This does seem odd, as there is virtually no cap on forecast profiles in the center of the risk area.

I must say the flow is ok in the direction area but non-existant in the speed shear area. I'm almost thinking more of multi-cell clusters that are more pulse severe in nature. Not very much of a tornado risk at all.... but mother nature has surprised us in the past....

I'll just sit tight here and watch for some hailers nearby to take pictures of from my front porch.
Agree with the general consensus of not much tornado potential today...but it is late May and is just enough of a glimmer to chase something to rotate initially across WC Iowa. Rich and Ryan Thies and I will be heading east on I-80 from Omaha here in about an hour, and holding in the area near Carroll IA. The 12z RUC does pop something of interest near Carroll IA by late afternoon/early evening in that vicinity. The RUC was also showing some good signals of enhanced 700 vv in this area and 0-3km ML CAPE near 100 j/kg. Not exactly an off the chart late May severe wx event, but decent enough to chase for the moment.
Nothing really looks good today, in terms for supercells at least. Deep-layer shear weakens rapidly ahead of the frontal boundary, with 0-6km shear generally 20-25kts across western IA and MN (in the warm sector). Nonetheless, the continuous insolation and strong diabatic surface heating will result in boundary layer thermals free to convect once the CINH layer is breached (through sufficient heating/mixing). In addition, widespread 67-70 tds will also contribute to extreme instability by the afternoon, with the latest RUC mesoanalysis showing widespread >3000j/kg sbCAPE ahead of the front. Given the meager flow at all levels, and unidirectional shear, I could expect some organized multicells and perhaps a few brief bow echo structures across the region through the afternoon (and perhaps an isolated brief supercell structure closer to the front). I'd expect low-level parcels to reach LCL and LFC closer (or perhaps just behind) to the front -- where low-level convergence will remain maxamized. LCLs aren't terrible today -- e.g. 1000-1200m AGL -- but not that it matters given the horrible shear... Maybe I'll get a non-mesocyclone tornado... Or maybe not :lol:

I'm in Sioux Falls, SD and will probably head east on I-90 in the next few towards Worthington, MN.
Headed out now, making the turn at Sioux Falls and heading east till things pop, probably Fairmont as the furthest. Good luck all

Change of plans, headed east on 14...sited a tower shoot up pretty quickly so I'd rather catch up with the line first.
My pick today would be the Woodward / Buffalo, OK to Greensboro / Meade, KS region.

The UCAR RUC is adverstising backing of the surface and 860mb winds by 0Z as upslope develops into southeastern Colorado in response to an approaching wave (not enough moisture for much in SE CO today however). A narrow band of 20+ kt winds at 700 mb is forecast to be flowing over the Woodward/Meade area, with 25 to 30 kt southwesterly winds at 500 mb, ~40 kt winds at 300 mb and 40 to 50 kts at 250 mb.

I wouldn't be surprised to see a few supercells, and perhaps even an isolated tornado in that area this evening.

Good luck to all who are chasing today.

Upslope tomorrow!
Just stopped for data in Salina - initial pick was Medicine Lodge - will continue down that way for now...I like the forecast of backed winds in that area southwards into NW OK.
I'm parked in Concordia KS attm. Parameters aren't good anywhere, but this seems about the optimal place to me, as it's near some shear, has good moisture and instability, and there is convergence here. I'm thinking of mosying down towards Salina, though, because currently the sfc air is still (i.e. still=no wind) right smack on the boundary here. Think I'll wait a bit, though, as the wf is progged to pass back over me here later on, and it's early.