April 5, 2010


Initial Target: Bethany, MO
Departure: Westchester, IL 9:00 am
Arrival: Falls City, NE 10:00 pm
Intercepts: Osceola, IA and Maryville, MO
Tornadoes: 0
Hail: Non-Severe (Pea sized)
Wind: Non-Severe (not measured)
Features: None
Miles: 643


Warm front setup in northern MO. Targeted NW MO where shear was maximized and capping less of a concern. Passed elevated supercell near Osceola, IA and north of warm front en route to target area noting undulated, outflow structure and hail covered road. Cap failed to break in NW MO until after dark. Ran into NE after storms that fired in NE KS, but cells evaporated before intercepting. Camped in the van for the night outside of Falls City, NE.

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.


It had been a long winter and too long since my last chase, which was July of the year before. I was dieing to get back out there, and Monday's setup looked like the first decent opportunity of the year. A warm front was forecast to extend from NE KS across northern MO and into IL. A dryline was also forecast to extend from NE KS into western OK with a large trough over the Rockies. Both targets had excellent shear and instability combinations with CAPE forecasted around 2000 J/Kg, 60 knots of bulk shear, 200+ 1km SRH, and large looping hodographs.

Significant Tornado parameters were forecasted above 7 on both the dryline and the warm front on the NAM model. The capping inversion looked like it was going to be the biggest problem with the setup, with a significant amount of CINH forecast to be in place until just before 7pm, when it was forecasted to weaken. The other big problem with the setup, however, turned out to be the lack of good lift to initiate storms. Convergence on the dryline was weak and the bulk of the upper level energy in the trough was still way out over the western states. I settled on the warm front in NW Missouri as this target looked like it would have the best chances of seeing daytime initiation with a weaker forecasted cap and still had extremely favorable parameters for supercells and tornadoes.

I left at about 9 am after getting the van ready, knowing that it was going to be a late show (if the cap broke). I took 88 to 80 across Illinois and Iowa. North of the warm front I encountered a few showers and weak thunderstorms along the way. Rounding Des Moines and heading south on 35 I approached one particularly strong cell that had been severe warned from quite some time. It had a rather classic supercell type appearance on the radar. Well north of the warm front I knew it was an elevated supercell and did not pose a tornado threat. The storm crossed 35 before I could core punch. There was a lot of undulated, outflow type clouds and pea sized hailed covered the highway where the storm had passed. I briefly considered following it, but after seeing the outflow dominant structure and knowing that it was elevated, I decided to continue on to my target in Missouri.

I drove down to Cameron, MO where I'd have a good road network to work with, and stopped for lunch. It was cloudy along the warm front and into central Missouri, but clearing across KS was nosing into western MO. The sunshine would destabilize the atmosphere providing the needed energy for thunderstorms later. There was also a nice cumulus field moving into NW Missouri with some towers attempting to go up. Things looked really promising. As the clearing moved north, so did the warm front and I was soon too far south. I drove up to Bethany to keep up with the front.

I waited a long time in Bethany, checking data and working on the software controlling the robotic camera dome, which had been acting up terribly. The county emergency management director stopped by after seeing the van and we chatted for awhile about the setup and some previous storms that went through the area. Things weren't looking so good after awhile. The cumulus field started to thin out and there was a lot of high altitude cirrus moving in now that would hurt the instability. It was also early evening now and the sun would be soon be setting, which meant no more heating and no more light to see storms. I still held some hope though as there were some towers on the visible satellite moving from NE KS into NW MO. The EMA director left and I watched the sun starting to set. Finally, we had initiation but it was 134 miles to my west in western Kansas. If I went for these storms I wouldn't intercept until long after dark. I waited around to see if anything else closer would fire. Jeff Duda and his crew pulled up and we chatted for awhile. They were ready to throw in the towel, and hadn't heard about the cells firing in NE KS. I decided that this was probably going to be the only play and I hadn't come all this way for nothing. I said farewell Jeff, who were heading back to Iowa, and made for the river crossing at Rulo for an intercept in Nebraska.

The cells in Kansas quickly gained intensity and went severe warned. The Storm Prediction Center issued a tornado watch. I was hoping the low level jet would aid moisture advection enough to keep the thermodynamics favorable for nocturnal tornadoes. The models had forecasted the low level instability to fall off after dark and the cap to strengthen, however. As I made for the river crossing, a line of storms started to form just a few miles to my south in NW MO. They were not warned and looked quite linear on radar. I decided to let them go and punch through them to get to Rulo. There was a smattering of pea sized hail and some lightning, but I didn't see any notable structure on these storms.

I lost data as I crossed the Missouri river and switched from ATT over to Verizon and was able to regain a connection to see the radar. The storms were starting to become messy yet severe blobs when I last saw them. Now they had been cut down to half their size. It looked indeed like the low level instability was gone and the cap was cutting off these storms. They were evaporating quickly and accelerating as the midlevel winds carried them away. As I came in to Falls City, NE I decided to call the chase off and looked for a place to spend the night. I found a quiet, gravel road just west of town, and pulled off to the side, climbed into the back and spent the night in the van.

The first chase of the year was a complete bust. I saw a couple of storms, an elevated severe warned supercell and a non-severe linear line after dark. The elevated supercell wound up being the storm of the day for me even though I didn't bother to chase it. The day was worth a shot though given the amazing parameters that could have resulted in tornadic supercells had the lift and cap erosion been there. It was also nice meeting Jeff Duda and crew.



Lessons Learned: 

  • Test the software more thoroughly before the first chase.