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On Friday, VORTEX intercepted a long-lasting supercell in
northwest Kansas. This was an HP supercell complex which at
times featured two or three mesocyclones in a tight cluster of
cells. Despite what is shown in the Local Storm Reports, this
storm produced only one possible identifiable tornado which
persisted for only about 30 seconds. It also produced softball
size hail, which intercepted two of our teams. Overall, this
storm was remarkable in that it had strong mesocyclones but
seemed unable to produce significant tornadoes.
A very rich data set was obtained:
* The NOAA P-3 and NCAR Electra obtained 25 coordinated passes
on a total of over 80 flight legs next to the storm.
* The new X-band scanning pulsed Doppler (a joint NSSL/OU/NSF
venture) obtained numerous volume scans of the supercell
complex. This was its first deployment after construction was
completed the 18 hours previously. Data quality appeared to be
quite high in playback of velocity and power after the event.
Kudos to Josh Wurman (and Ling), Jerry Straka, Allen Zahrai,
Dennis Nealson, Paul Griffin, and Mitch Randall (NCAR) for a job
well done.
* Numerous soundings were obtained in the mesoscale environment,
storm inflow, forward-flank region, and updraft of the storm
(updraft ascent was 38 m/s).
* Two teams were pummeled by hail up to softball size just north
of the low-level mesocyclone. Coordinated surface deployments
were not possible; the "rules of engagement" for fast-moving
storms is that we only deploy when there is a near-certainty of
a tornado passing across the deployment area. This did not
occur on Friday. Based on the two vehicles that were damaged,
it appears that this was a good choice: severe damage to most of
the fleet would have been unjustified given the data set that
would have been obtained.
Finally, thanks to Jason Levit for his support from Norman Ops
Center yesterday.
The Groundhog's Day adventure continues.
Erik Rasmussen
Jerry Straka