STEPS 2000
JD 00177 25 JUNE 2000FINAL SPRITE LOG
The following is the final listing of the times of sprites imaged at the Yucca Ridge Field Station. These are on visual inspection of the LLTV video monitoring system. All times are UTC. The times refer to the start of the 17 ms field in which the TLE was first visible.
SUMMARY: Halo/sprite over LMA during dying phase of supercell, associated with last positive CG of storm. Full operations. Cells formed in eastern CO (some dry microbursts along Front Range) and moved eastward. Relatively limited upscale evolution was evident around sunset. Had reasonably rapid clearing of debris clouds and fair to good viewing through moonrise at 0730Z (which terminated LLTV operations). One supercell-like storm moved east-southeast from triple point of CO-KS-NE border. Had mostly +CGs, but extremely high IC rates (well over 1/sec for an extended period of time). As cell moved north of GLD it began weakening (after 0430Z). It the then briefly re-intensified around 0500, reaching 61 dBZ and 50 kft. It was rapidly re-weakening with CGs ending when it launched a single halo/sprite. While the radar echo was not that large, the cloud canopy was quiet extensive (though not especially high). This may have been with the last CG of the storm. The stratiform area was up to about 7500 km**2 at the time. Other cells over the next two hours produced spectacular IC flash displays. Could easily see illuminated towers from YRFS. Flash rates often greater than 1 sec (essentially continuous). The associated CG rates were quiet small. Did not focus on MCS in panhandle area because of both clouds and distance form LMA. Have excellent GEN III images of ICs from hot towers. Sampled VLF, PD, and PMT (only got VLF for sprite as tracker was on another cell at the time). No nowcasts issued. VLF signal was out during early part of tapings. Recycled tele LLTV tape.
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(S) = Sprite; (E) = Elve; (B) = Blue Jet; (CF/CG) = Cloud/Ground flash; (M)=Meteor
ON 0300 UTC
OFF 0740 UTC
O529. 05.983 (Halo, Spite)
(Only event this night)