Wednesday, April 14, 1999
Tim Vasquez & Shannon Key --
With a cold-core low crossing southern Oklahoma and clear skies and
60-ish dewpoints here in Norman, it looked like we'd get a round of
Cb's springing up in relatively clear skies -- a great photo opportunity!
Shannon Key and myself headed north out of Oklahoma City at 2000Z.
We drove straight north to escape a broad cirrus shield threatening to kill
solar heating, hoping that the area along the fringes, near Stillwater,
would "light up".
As we passed Guthrie around 2030Z, we saw that a N-S line of hard
towers was forming to our west. As we were expecting an E-W
orientation, aligned with the clear slot, this suggested that the cold
front was at the heels of this cumulonimbus line. Near Mulhall, and
with nothing forming in the clear slot (now filling with cumulus), we
decided to head toward the main tower in this line, which was now
darkening the western sky quite ominously.
By 2100Z near OK51/OK74 the storm was in plain view -- the features
were somewhat linear but a rounded updraft base began coming
together to our SW and inflow was quite healthy, with winds out of
100/15 kt. We dropped south to Crescent, and at 2116Z the base
started rotating rapidly. I stopped and got a tripoded shot of this
circulation, about 3 miles to our WSW. Wow!! This lasted only
about one minute, and the cell then gusted out and sent us scrambling
southeastward, closely followed by a rain/hail-filled core. We parked
east of Guthrie, but by this time it was looking very outflowish. We
tailed the linear updraft east to Langston and Perkins, watching it
transition into a messy squall line structure.
The "vaulted" updraft was remarkably detached from the precipitation
area, forming incredible "sideways"-oriented bubbles on the sides of
the vault. I stopped near a house south of Perkins and grabbed my
still-camera bag out of the trunk -- two dogs immediately bounded off
the porch running for me, and I jumped back in the car and had to
blow the horn to get the dogs away from the car. I was able to move
just in time to get some photos of this vault before the weak rain core
caught up. We left the storm there, heading back to Norman under
beautiful, scud-filled skies (with VERY low bases) that alternated
After we got back I looked at some radar archives and saw that the
Crescent cell had an interestingly "kidney-bean" shape at 2130Z. Was
anyone else on this storm? What did you see? Did anyone look at
any velocity products? Given that we were just out for some
photogenic Cb's, this was a *lot* more than we had hoped for!
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Return to 1999 logs
Radar data provided courtesy of Weathertap, Inc.