April 3, 2003 Chase Summary  

The cold, hard numbers behind this chase.

Thursday, April 3, 2003
Length of Chase
5 hours
Distance Covered
131 miles
...for the year
461 miles
Chase Partner(s)
(solo chase)

What in incredible chase! The day began with a line of showers moving east through Oklahoma. By mid-afternoon, the showers pushed into eastern Oklahoma with dramatic clearing in the wake. The low-level moisture had increased, thanks in part to the earlier precipitation and strong moisture advection. The dry-line had also become better defined. Here are some surface maps: Southern Plains (2015Z), Oklahoma Mesonet (2015Z, 2125Z). The SPC's mid-afternoon convective outlook upgraded southwest Oklahoma from a "general thunderstorm" to a "slight" risk for severe weather.

With backing surface winds and a tightening moisture gradient, the low-level convergence was strong enough to overcome the cap. By 2:45 PM CST, towering cumulous, from what was to become the lone storm for the day, could be seen firing-up along the dryline in far southwestern OK. At 3:20 PM, a severe thunderstorm watch was issued until 8 PM.

I looked at data for a while, contemplating the importance of chasing over work responsibilities. By 3:45 PM, the storm looked good enough to get me out the door on a solo chase. I drove to Chickasha, continuing west out of town on HW-9. At that time, the cell was near Hobart, moving ENE...looking more and more impressive as I approached.

I found a great vantage point on the top of a hill, just east of Fort Cobb. I set-up a video camera and shot some spectacular time-lapse footage of the storm, which had become supercellular. Grapefruit sized hail was reported 8 miles southeast of Gotebo but I was lucky enough to miss the hail and only briefly got drizzled on. I watched the isolated, high-based, low-precipitation beauty at the spot for almost an hour before I had to move back east to stay ahead of the circulation. Although, according to the Norman NWS forecast office, the storm showed signatures of a strong mid-level mesocyclone, no significant wall cloud ever formed.

The resultant time-lapse footage (see below) is breathtaking and has been featured in a number of tornado/severe weather documentaries, including Nature Tech: Tornadoes, produced by the History Channel.

At sundown, the storm began to lose some of its furry before pulsing back up an hour later as it approached Amber. I followed it east, ending-up in Blanchard before it completely died, at which time I called it a day. I arrived back in Norman at 8:45 PM.

Chase Route  

Chase Video  

  • Fort Cobb, OK Supercell Time Lapse: April 3, 2003
  • This incredible time lapse footage has been included in a number tornado documentaries.
  • Length: 1 min 42 sec

Chase Photographs  


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