JD: 00-175 DoW: TH/FRI UTC Date: 23JUNE2000

SUMMARY: Many Sprites In or Near LMA

TLE PREDICTION: 0.63 [0.9 x 0.70]

RESULTS: Classic MCS regime with sprites

LESSONS: Best Case So Far; Check sprite/bright band relationships

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

STEPS STATUS: STEPS operates. Works until 0300Z.

YRFS OPERATION LOGS: Full operations. Classic development of MCS off Denver cyclone convergence line. Smaller cells, several severe, gradually merged into larger MCS that moves basically eastward, though intense cores had clear right-moving tendencies. Numerous meso and hail reports from NEXRAD. Tops to 550-600 with 66 dBZ reported. System nearly achieved MCC status (must check). Had very high percent positive until well after dark. Local debris clouds between YRFS and LMA made viewing difficult at times. Saw many sprites through holes in the clouds. After 0630Z, moon became a problem and could not cover all of the southern portion of the system. Sampled VLF, PD and Winckler PMT. Had some very good hits, but trigger device was sticky and missed some samples. Some telescope views. GEN III again appeared to provide better detection efficiency. Heard many more VLF sprites that actually saw on LLTV due to persisting clouds. Sprites gradually waned after 0700Z as storm weakened. Some spotty cloud tops to –75C just after dark. Mark Stanley could not use interferometer but did record field changes. Three tapes with red patrol, red zoom and red tele. Also 3 S-VHS copies with GPS of GEN III system (with 5 DVD tapes). Some VLF interference until source found around 0600Z. Visibility fairly good, but some haze remains.

STEPS OPERATIONS: STEPS goes for early ops. Sampled strong cell on southern end of line.

Mark filled Interferometer up with 13 GB of data during afternoon, had no storage for nighttime. Operations on Thursday concentrated on a severe cell centered in the western Doppler lobe as of 5:00 MDT that was at the southern end of a well organized MCS and which was exhibiting a predominance of positive CGs. The original target cell collided with another severe cell that moved northward from the Burlington area between 6:00 and 6:30 PM, With the resulting storm complex then propagating towards the east-northeast over the S-Pol radar site. Up to 1 in hail was reported with these cells along with surface winds up to 30 ms-1 and a brief, weak tornado 4 miles west of Idalia about 6:00 PM. The T28 was called out at 5:00 PM along with the storm intercept and the mobile ballooning units, who were vectored to near Idalia for soundings and ground verification. The T28 did transects of the storm system between 5:50 and 6:50 PM, experiencing significant turbulence, icing, hail, and frequent lightning. An initial tandem electric balloon was launched into the updraft, but failed as the instrumentation separated from the balloon shortly after launch. Two successful balloon launches were obtained on the western side of the storm system. The lightning mapping network depicted a large positive charge layer within the storm between 6 and 9 km.

Radars continued coordinated scans of the system through about 9:00 PM, as it moved northeast of the Goodland area, within the eastern dual Doppler lobe.

KEY RESULTS : Best night so far. Many sprites observed in or near the LMA coverage area in a well defined trailing stratiform region. Strong apparent association with the secondary reflectivity maximum/bright band which in this case was more north than west of the convective core. Sprites appear to fit the conceptual meteorological model very well.

Total TLEs from Yucca Ridge This Campaign: 390

FMA

Red Xybion (A)-Patrol: 3 tapes

Sony TRV900 3CCD: shot TL scenes of clouds;

GEN III unit; 5DV tapes w/ sprites; 3 S-VHS w/ GPS

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

Pulnix CCD: shoot various TL scenes

Photodiode: sampled -but moon interference alter

Winckler PMT: sampled-but moon interference later

GPS: OK

WWV Source: OK

VLF Inspire: sampled

ELF N-S: not available

ELF E-W: not available

NLDN Live: OK

NLDN Paper: 17 maps

NLDN Archive: 4 saves

MRC Data Acquisition: OK-sticky trigger, missed some samples

FMA Data Acquisition: not available

Thunder Mic: available

LANL Tracker: OK

Red Xybion (B)-Zoom; 3 tapes (on tracker)

Red Xybion (C)-Tele: 3 tapes-on tracker

Blue Xybion(D)-zoom: 0 tapes - problems with focus

Mountain Cam: nominal

STEPS Cam: nominal

Shure Mic: OK

NEXRAD Archive: Revised EDIS; Many manual saves

GOES Archive: OK

RUC2 Archive: OK

STANFORD/STAR LAB:

Telescope OK-good data

LLTV OK

ELF/VLF OK

UTAH STATE UNIVERSITY: not present

MIT ELF: problems with vertical antenna?

FUELLEKRUG ELF: operational

ISRAELI ELF: nominal