2011-05-21: FCST: TX, OK, KS

[Tim Marshall]

Today is a marginal chase day. I see two targets: Emporia, KS and Paris, TX. The Kansas target has cooler temperatures aloft and upper forcing is better due to its proximity to the upper low. CT at TOP is 82, definitely reachable. However, the RUC wants to veer the surface winds and keep CAPES lower. I also have logistical concerns as it would be a long trek for me to drive up there -then get back down to Red River for Sunday. Down in Texas, I like the higher CAPES, dryline bulge, and strong mid-level winds. RUC wants to back the surface winds ahead of the dryline bulge. However, CT at FWD is 92, which is a bit high for forecast temps today, but RUC wants to break out precip in both areas. So, it looks like I'll monitor from home today until something pops up locally.

 

[Tim Vasquez]

I have not analyzed the area south of Dallas, in any great detail up until now, when I noticed what appears to be a potent setup. Shown here in blue is the Corpus Christi sounding modified for afternoon heating.

Now I do see soundings like this a lot in the late spring, and with a convective temperature of ~102F there is usually not any cause for concern when this kind of SKEW-T appears, but given the presence of a sharp boundary west of Austin and Waco, the fact that 850 and 700 mb temperatures do drop as you go north, the fact that the CAPE is easily 5000+, and with the Cu fields are now organizing around Fredericksburg and Mason, this would almost certainly be a big chase day if I was still living in Austin.

Tim

 

[Brandon Lawson]

The 15z RUC continues to show really impressive surface-based CAPE values (around 5000+ J/Kg) ahead of the dryline this evening, from south central Oklahoma down into Texas, as upper 60's dewpoints advect into southeast Oklahoma. While the upper-level support is not real impressive, forecast soundings around the Red River area from Ardmore to Atoka, Oklahoma show a veering wind profile from the surface, up, with 40 knots of bulk shear, backed 925mb flow of 30 knots, and south-southwest 850mb flow of 35 knots at around 00z. This would result in 0-1km EHI values of 5-7. The infallible HRRR along wth the 12z 4km WRF and RUC show a storm or two firing in SE OK later this afternoon. I don't think I would be able to make it down into Texas, should storms remain further south, but I'm still somewhat interested in anything that might go up in southern Oklahoma.

 

[Michael Riedl]

Storm that just left topeka taking a hard right turn now, very nice hook echo showing up, it is an area of heightened Effective SRH now,. populated area

 

[Michael Riedl]

Storm just blew up and matured extremely fast in Lyon County KS, insanely strong couplet with what appears to be a debris ball.

In an area of 400 ESRH.

 

[Matthew E. Engelbrecht]

Yes, a very deep/strong V couplet passed very near Reading, KS at 0215Z. Very high SW values at the tip/ball of the hook echo may indicate tornado debris, as you mentioned. A new storm about to pass south of Lyndon, KS is showing signs of an organizing mid-level mesocyclone with increasing rotation at low levels. The Reading storm, now north of Ottawa, may pose at least a large hail threat to the southwest Kansas City metro area between 11 pm and midnight (central time) as it persists with a broad mid-level mesocyclone. 70 degree dew points are contributing to SBCAPE of 3500 along I-35 into the Kansas City area. Surface observations indicate winds veering to the SW at KIXD and KOJC, so 0-6 Km helicity may be locally minimized in the area which may cause the storm mode to change. This would be a good thing as these storms move into populated areas...