Tuesday, April 28, 2009

Waterloo!!

Oh Sunday. The big High Risk day in the central plains. I screwed up nicely, but not in the same fashion that a lot of the chasers in Oklahoma and Kansas did by missing the Roger Mills tornadoes in NW Oklahoma. No, I chose to sit that event out due to the long distance that would need to be traveled and the iffy storm mode forecasts. It was either going to go big, or be a huge waste of time and being early in the year still I decided to opt for a closer target that still showed some potential. The dreaded state of Iowa.

Heading to bed on Saturday night I did some forecasting online with buddies Jarrod Cook, Scott Kampas and Mark Sefried. I first eyeballed southwest Iowa. Looked like the instability axis would nose up in that location co-located with very strong low level winds ahead of the surface low in eastern Nebraska. Then something else caught my eye. It looked like a shortwave would be located over central Iowa in the earyl afternoon, leading to a very favorable tornado environment around the Waterloo, IA. I went to bed with Waterloo, as my target. It was a short 4 hour drive, and showed decent potential should the WRF verify.

I woke up around 6:30 AM to check things out. I wanted to wake up early enough that should SW Iowa look good with morning data I could still make that area in time. I wasn't pleased with anything that I saw. The entire state of Iowa was covered with low clouds and rain. Looking further west was not any better, as new thunderstorms were already forming in Kansas and Nebraska and moving into the state. I about set my laptop down and went back to bed right then, and probably should have done just that. However, as most know by now, it was the day before my birthday and I really wanted to get out there and see some storms. I decided to wait around for the 12Z RUC models to come in.

Bam! The RUC throws out 3200 j/kg CAPE and 300 m2/s2 low level helicity over SW Iowa. Wow... perhaps Iowa -will- clear out in time? I thought surely the eastern Iowa Waterloo target would not clear out in time, but perhaps SW Iowa would indeed, as I had thought the previous night. I decided I didn't have a ton of time to wait around and see, because if it did clear out but I was still sitting here in Champaign I'd likely be too late. I talked with Jarrod and Mark and came to a general consensus that we'd just drive halfway, check it out, and continue driving if warranted. I hopped on Interstate 74, took that to Highway 34, and kept trucking into southern Iowa. I didn't stop until I hit Ottumwa, IA. It had that "feel". Eastern Iowa just felt like a tornado day there. Any chaser who has been out there for a while knows what that feels like. It was hot and sticky, low level cu were racing from north to south and the southeast surface winds were howling. I should have stopped there! Perhaps eastern Iowa -was- clearing out! No, I continued heading for my other SW Iowa target.

Arriving in my target area, things already looked terrible. I met Mark and Jarrod in Creston, IA where we had a mostly non-severe squall line to our west, and nothing forming out ahead of the line at all. We noticed a few returns in northern Missouri and decided to give those a play, as it was our only hope. It was as we turned around and headed back east that I looked further NE on the radar screen. A lone supercell was tornado warned right next to Waterloo, IA. Bah!

Not only did the Waterloo target verify, it verified with a 21 mile track stovepipe tornado. The tornado rivaled the Roll, OK tornadoes that everyone is mad about missing in Oklahoma. Here's a shot taken by a local: http://media.kcrg.com/images/600*450/Tornado%20001.jpg

That's why the technology age is so "nice". If you blow it and miss something, it's no problem. Twenty people who had no intentions of seeing a tornado that day like you did, will be there out of dumb luck to film it and rub it in your face!

I'm not as upset about this one as I otherwise might have been. Looking back at radar data and such, even if I had gone to Waterloo, I don't know that I would have believed such an event would have happened. A mushy line traveled across eastern Iowa, that apparently hit the warm front and morphed into a tail end charlie supercell. Of course, being in Waterloo I would have given chase and at least been in intercepting distance once things started looking up.

Jarrod, Mark and I spent the drive home discussing over the radio all the reasoning behind our decisions, and what to change next time. We did come away with a wall cloud on one of the cells that originated out of northern Missouri, but it didn't compare with what happened at the target that we picked 24 hours earlier. Ah well, such is chasing. Especially chasing in Iowa. As Jarrod and I said last night after we saw the photos of the tornado, it only makes us want to get out and chase that state even more to show it that we will see a tornado there sometime.

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