approximately 1941z about six miles south-southeast of Seymour Texas, April 13, 2007

Eric Nguyen and I observed a large tornado at 1938z which was on the ground for at least six minutes and probably longer as we lost visual once it wrapped in rain. 

We had targeted an area from Throckmorton to Ranger but elected to go west on I-20 rather than SR 380 because we lacked confidence that significant instability would develop northwest of DFW.  Moisture seemed to be advecting mainly into areas further west and southwest and the early RUC, even as it increased the "wrap around" moisture north of the surface low, generated little CAPE there.  We assumed this was a function of cloud cover and cool air associated with (model-depicted and mostly imagined) WAA storms and earlier convection.  We suspected this could hold the warm front along or just north of the interstate and we wanted to play storms crossing the boundary.

We stopped in Ranger and took lunch at El Rancho Cafe where Tony Laubach, Tom Dulong, and their friend Jenn joined us.  We emerged to a very different situation.  Now our skies were dotted with cu and it was apparent the front had sailed north without us, much like 07 April 2002 when Eric and I both missed the great Throckmorton tornado for the same reason.  This was heavy our minds because, on the way to Ranger, we had replayed the first episode of Gene and RJ's "High Instability" radio program where the hosts and Dr. Doswell discussed that particular event.  Imagine our amazement when we realized this storm to our north was intensifying and probably about to traverse the warm front as it neared...where else?  Throckmorton of course.

We headed north and finally gained a view of the base from about ten miles south of Seymour.  We observed intense rotation west of the road, followed by strong RFD and occasional baseball hail. The tornado crossed 183/283 approximately six miles south of Seymour and we observed a fully condensed wedge tornado from near that location as it moved to our east northeast.  For survey purposes, I would place the tornado at its most violent between 183/283 and SR 114, perhaps between Ogden Road (FM 1286) and CR 226.  The tornado wrapped in rain and continued northeast and almost certainly grazed the C Lazy T Ranch on CR 222.



From there we tried to maintain position relative to the mesocyclone, but it was apparent the storm had crossed the front and suffered from more stable inflow.  We dropped south but observed nothing more interesting than some elevated albeit pronounced rotation in a forward-flank meso in extreme northeast Palo Pinto and northwest Parker counties around 22z, about when Fort Worth warned on the storm.

We meandered back toward the metroplex listening to radio coverage of the storms moving through Tarrant and Dallas Counties, an experience which was, as Eric described, "sobering."  We were both glad to see the damage to life and property is relatively minimal.

We had a great dinner with Tony Laubach, Tom Dulong, and their friend Jenn--all from Colorado, plus: Jeff Snyder, Robin Tanamachi, Dan Dawson, and their friends Mike and Janna. 

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