JD: 00-156 DoW: SAT/SUN UTC Date: 04JUNE2000

SUMMARY: Strange "Elve" Storm in SD; Hailstorm Null Case in NE; GEN III

TLE PREDICTION: 0.42 [0.6 x 0.7] possible MCS in NE after dark

RESULTS: 27 events…virtually all "elves"

LESSONS: Some storms make all "elves"…other make no TLEs at all

PERSONNEL: Lyons, Nelson, Fossum, Nordem, Gerken,

STEPS STATUS: Operations late in day.

YRFS OPERATION LOGS: Few small cells moved off mountains in afternoon but no real convection developed anywhere along Front Range. However, several systems in Midwest allowed for longer range viewing. An MCS in eastern NE and Iowa grew to rather large size towards midnight. Though viewing was near optimal, we never say any TLEs form this system. It did have relatively low flash rates, and it is possible that thin smoke limited viewing at sub 3 degree elevations at these longer ranges (700+ km). The much more intense MCS in SD moved southeast. It began producing elves around 0539 Z. There were about a dozen "elves" in as many minutes. Several were very large, but many were very small, thin disks which tended top form in the same place. They appeared clearly in the ITT GEN III system (first use tonight!), and the red and blue Xybions, as well as the Stanford camera. The TLEs were associated with very sharp, crisp loud VLF bursts. Definitely not sprite-like VLF. Not sure if any sprites were seen from this system, which had relatively modest stratiform region, and many intense convective cores (>65 dBZ). The events lasted for about two hours. Then a new cell formed almost in the field of view at about 400 km range, producing many cloud flashes. This cell had low CG rates, but a high percent of positive. It had multiple cores and reached 71 dBZ, most likely a hailer. Cloud flashes greater than 1 a second, but as storm developed and moved southeast, never saw any evidence of a TLE. Class null case (though this storm may have produced TLEs after shut down). While originally on the northeast fringe of the LMA, the storm was out of LMA range so a decision was made to terminate. Thunderstorm watches issued for SD, ern NE MN and IA storms, but not central NE storms. Mounting ring on GEN III did not fit quite right, causing some blurring of image.

STEPS OPERATIONS: operations late ? (see logs)

KEY RESULTS : (1) Very unusual "outbreak of elves, and maybe halos (?), some in rapid succession from intense MCS. Monitored hail in NE as null case – no events. (3) GEN III system shows potentially superior performance.

Total TLEs from Yucca Ridge This Campaign: 190

FMA

Red Xybion (A)-Patrol: 2 tapes

Sony TRV900 3CCD: 4 tapes (for GEN III), plus late day TL

GEN III unit; worked very well; shot almost 4 Sony Tapes (routed to one S-VHS)

JVC KY-19: shoot daytime TL/STEPS Cam (to ESE);

Pulnix CCD: shoot various TL scenes

Photodiode: lens mated to original unit, waiting to be tested

Winckler PMT: available

GPS: OK

WWV Source: OK

VLF Inspire: OK

ELF N-S: not available

ELF E-W: not available

NLDN Live: OK

NLDN Paper: 12 maps

NLDN Archive: 2 saves

MRC Data Acquisition: new trigger ready

FMA Data Acquisition: not available

Thunder Mic: available

LANL Tracker: OK

Red Xybion (B)-Zoom; 0 tapes

Red Xybion (C)-Tele: 0 tapes

Blue Xybion(D)-zoom: 2 tapes

Mountain Cam: nominal

STEPS Cam: nominal

Shure Mic: OK

NEXRAD Archive: OK

GOES Archive: OK

RUC2 Archive: OK

STANFORD/STAR LAB:

Telescope OK

LLTV OK

ELF/VLF OK

UTAH STATE UNIVERSITY: not present

MIT ELF: problems with vertical antenna?

FUELLEKRUG ELF: operational

ISRAELI ELF: nominal