The cold, hard numbers behind
April 3, 2003
|Length of Chase
|...for the year
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,
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
along the dryline in far southwestern OK. At 3:20 PM, a
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.