Chase Log: April 21st, 2005


Click on any of the SPC products below (Convective Outlooks, Watches, or MCDs) to see the SPC's "Severe Thunderstorm Events" page pertaining to this event.


MAP
(ZOOMED)

Total Distance: 700 miles
Target Area: Tulsa to Bartlesville, OK
Chase Area: Columbus to Cherokee, KS, to Jasper to Mount Vernon, MO
Maximum SPC Risk category: Moderate
Watches: Tornado Watches 175, 178, and 181, Severe Watches 177, 179, 182, and 184
Mesoscale Discussions (MCDs): 624, 627, 629, 630, 632, 633, 634, 636, 637, 638, 639, 643, and 644

Finally, it appeared that there would actually be some substantial low-level moisture in place across the TX/OK/KS region as characterized by mid-upper 60s dewpoints. However, opposite of the previous chases this year, mid-upper level flow was progged to be relatively weak across the area with best instability. Nonetheless, 2000-3500 j/kg sbCAPE and 30-40kt 0-6km deep-layer shear looked to be sufficient for a nice supercell threat across eastern OK and KS.

I headed out with Gabe Garfield around 12:30 after finally deciding on ne OK over area near I40 and southward. Optimistic about the SSE sfc winds in far ne OK and se KS. TCU struggled with the cap / weak convergence for a while, with lots of turkey towers. Had one storm that look nice north of Miama, and headed towards there. That storm fell apart rapidly, so we continued north into se KS. Talked to Phil back in OUN, notifying us of tornado warnings for storms to our west and north. The "storm" to our immediate west near Chetopah looked like trash, and we heard of a large tornado on the ground northeast of Parsons. Busted northward to catch up, and, over the next few hours, saw MANY wall-clouds, RFD occlusions, and the like. For the most part, the storm appeared to be HP, with wrapping rain curtains and plenty of precip in the RFD region, as well as in the inflow region. It seemed as though we had experienced three RFD punches while near Cherokee -- the first one wet and cold, the second one warm and dry, and the last one wet and cool. At any rate, we followed the storm from northeastern Labette co, into far southern Crawford co, then east-southeastward across northern Jasper. I heard of several tornado reports on ham, though I seriously doubt many of them. We were lookin at the action area for the vast majority of the time (when not fighting trees), and I never saw any tornado, despite the numerous reports. There was a time when I think someone reported a tornado that was actually smoke/vapor from a smoke-stack...

Since it was pretty much dark by the time we reached just south of Jasper, we were going to call it a day. To our south, however, we noticed a very blocky wall-cloud. We figured we could stick with this storm for a bit longer, so we moved east and south on a semi-zig-zag pattern. SGF kept saying this thing was moving east, but I think it had an ESE motion. A few very large wall-clouds from southeast of Jasper to north of Avilla. We were going to let the storm pass us in Avilla, but when strong winds and falling leaves, branches, etc, hit us, we hauled east towards Miller... Now wanting to get out of harm's way, we tried jogging south on 97 towards I44. We stopped 5-6 miles north of Stotts City to watch the action, as it appeared that an RFD punch was occurring to our immediate north. At this time, we saw one VERY low wall-cloud feature to our north, though there seemed to be rising scud and rotation everywhere from out north to our west. The RFD hit us quickly (well, I think it was the RFD, haven't checked out radar yet), again with VERY strong winds and falling leaves, branches, etc. We were actually ALMOST stopped by a train north of Stotts City, though I was just about on the tracks when the red lights started blinking. At any rate, we hauled south towardsI44, then west to call it a day. On the way towards Sarcoxie, we experience rainfall like I have never experience so far. To say that it was raining in sheets is a huge understatement. Whatever the case, with SGF continuing to say that a tornado appeared very likely given radar images, we were glad to be out of a situation in which we always felt like the storm was chasing us.

The lightning activity with this storm was the most intense I have ever witnessed! CC and CG lightning seemed nearly continuous for most of the time southeast of Jasper... It was absolutely incredible. I have never, never seen a storm with as much lightning as this one had.

All in all, a little disappointing that we missed the big tornado from this storm by about 15-20 minutes, and also disappointing that this thing didn't seem to produce after that one. That said, multiple meso occlusions and many wall-clouds made the trip worth it.

04-21-2005 Chase Pictures

Click on any photo to see a larger version

One of several TCU clusters that bubbled up and down through mid afternoon as we sat in extreme northeastern Oklahoma. After watching TCUs struggle, it was a very relieving site to see this Cb rapidly develop to our northeast (in northwestern Craig County I'd imagine). We tried to catch up to it, but by the time we made it to Vinita, it had fallen apart. We then heard of the tornado-warned cells in southeastern Kansas, so we busted north into southeastern KS. One of numerous wall-clouds as the supercell moved across southern Crawford county west-southwest of Pittsburg, KS. There were a couple of very evident RFD surges, after which time wall-clouds would become better established. Another wall-cloud attempt as the RFD surged around the southeast side of the mesocyclone. Interesting enough, it felt like there were two RFD surges. The first surge felt quite cold and contained some light rain/drizzle, and the second surge was quite warm.