April 29, 2010

Statistics:

Initial Target: Osceola, IA
Departure: Westchester, IL
Arrival: Nebraska City, NE
Intercepts: Beatrice, NE Lewiston, NE
Tornadoes: 0
Hail: None
Wind: Non-Severe (not measured)
Features: Wall Cloud, Rain Free Base
Miles: 679

Summary:

Dryline/Coldfront play in southeast Nebraska/southwest Iowa. Targeted Osceola, IA ahead of eastern surge of cold front. Storms failed to organize and raced west into Nebraska after tornado warned supercells. Intercepted first supercell west of Tecumseh noting wall cloud but storm quickly fell apart. Continued west to next tornado warned supercell noting wall cloud, massive HP structure, and continuous thunder. Followed storm after night observing lightning illuminated structure before letting the storm go. Spent the night in van near Nebraska City close to reported tornado.

Crew and Equipment:

Solo chase.  Equipment:  Kenwood TH-F6A Tribander, Dell Inspiron Laptop.  Kyocera data card and router, Holux 236 GPS, Robotic camera dome with Sony XR-520V.

 

Video:

 

Details:

This was the first day in what I had hoped was a two day chase trip. I targeted southwest Iowa near Osceola where a cold front was forecasted to surge east ahead of the dryline draped over central KS.

I stopped for gas, food, and data in Osceola at the spot where there was a large chaser convergence on 4/6. I was the only one there this time though. I saw a line of cumulus starting to build on the visible satellite in north central Kansas but decided it was too far and that I would wait for my target area to light up. Storms went up in north central Kansas and southeast Nebraska. I made my way down into northwest Missouri catching some of them as they moved east and hoping that they would organize. They did not. Meanwhile the storms in north central Kansas were starting to go tornado warned. I knew I would probably miss the show, but I decided to blast west after them as they crossed into Nebraska.

A pair of supercells crossed into southern Nebraska, the western one producing a brief dust whirl tornado under a rotating wall cloud that was caught by other chasers. After getting stopped for speeding south of Tecumseh, and let go without a ticket, I got a view on the eastern supercell. I approached from the east on highway 4 as a large mesocyclone (top) and rain free base with wall cloud (bottom) came into view.
As I approached and highway 4 turned to the north, I could see there was some interesting activity going on under the wall cloud.
Scud fingers under the wall cloud:
I stopped a couple miles short of the wall cloud where highway 4 turned west again. A couple of other chasers pulled in behind me and we talked about the storm. The wall cloud was not rotating and was starting to fall apart as it looked like the storm was gusting out.

With the storm quickly falling apart, I decided to let it go and catch the next tornado warned supercell further down the road to the west, which had a beastly high precipitation appearance on radar.

Looking straight up at some mammatus:

I intercepted the storm several miles east of Beatrice right at dusk. A huge, ground dragging rear flanking gust front came into a view with a nasty looking core behind it.
The lightning on this storm was just incredible. It was the best I had seen all year. The thunder was equally amazing. It was a continuous rolling thunder with no breaks. The last time I had heard continuous thunder was on March 28, 2007.
The northern end of the gust front looked like it had a better organized wall cloud with the rest of the structure being more like a shelf cloud. As it moved over Beatrice the city lights illuminated the bottom of it in a dull orangey color. Thankfully it didn't drop any tornadoes then. The other two chasers whom I met up with earlier were parked next to me with their tripods setup and video rolling. The gust front started to move overhead and probably with just seconds to spare before the core hit, I said goodbye, and blasted back east out ahead of the storm. I hope they got their cameras back in their car in time.
Now a full fledged night chase, I had plenty of lightning illumination to work with. The after dark structure was incredible.
The high precipitation supercell had a huge bowing lowering that looked like a vertical wall moving along the country side where it met the elevated base at a right angle. It was the best structure I had seen yet this year.
Scud fingers reaching out like a creepy hand:
The storm lost its tornado warning but I continued to follow it towards Nebraska City.
I stopped for the night just west of Nebraska City on a gravel road, after almost getting stuck in thick mud trying to stay out of the way by parking on a less traveled side road. Lots of storms had gone up all around me and one of them went tornado warned with a tornado reported just a few miles from my location. It made me feel foolish for not being out there spotting it, but who knows if the report was legitimate, or if I could have caught it with so many storms going up around me even if it was.
Conclusion:

Between the wall clouds, amazing nocturnal structure, and lightning this was a fun chase and a success. I didn't feel too bad about missing the tornado in north central Kansas as it was just a brief dust whirl. The storms themselves were more impressive.

 

 

Lessons Learned: 

  • Make sure the roads are at least gravel when stopping for the night.