The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Cells began producing lightning early over southern CO Rockies late morning. System slowly drifted eastward into High Plains and southern Kansas ahead of cold front during evening. Daytime cirrus and debris gradually cleared after sunset. Turned on 12.5 mm red for test at 0400 and started seeing sprites from the north side of the southernmost of two cells in Kansas. Radar echo was definitely >20,000 km2. Sprites occurreed at a fairly regular interval (every 4 minutes) for more than an hour. Then slowed down. Cell was like many others this spring - had unusually high number of +CGs (>80%). FORTE pass just after video began. No moon. Some background aerosol from fires in Douglas County and perhaps some residual smoke from the central American fires.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)=Meteor JD 98139 19MAY98 0400 Start obs 0530 End obs0407.05 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Extraordinarily high sprite rate storm. Record to date for TLEs from one night. Thunderstorms moved off foothills during early afternoon. Tornado watch from NE CO and NE by evening. One large MCC moved slowly eastward through NE during the night. A second system formed in eastern CO around sunset and followed more or less in its track. The second system was smaller and had more squall line-like features. It produced some sprites late in lifetime, but was generally not producing many TLEs. The MCC on the other hand generate sprites (but only a few elves) at a rate not seen before. The sprites however tended to be rather small (c-sprites and smudges). Most were viewed at 350 km and beyond. Several FORTE passes. No moon. Very good star field once debris clouds evaporated but there was still some background aerosol from the central American fires.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)=Meteor JD 98140 20MAY98 0251 Start obs 0700 End obs
0331.05
[S-]
0331.50 [S]
0333.10 [S-]
0334.05 [S-]
0334.46 [S-]
0336.15 [S]
0338.25 [S+]
0339.40 [S+]
0340.46 [S]
0341.00 [S-]
0341.48 [S-]
0341.49 [S]
0342.15 [S-]
0342.30 [S-]
0342.50 [S-]
0342.57 [S+]
0342.59 [S-]
0344.00 [S-]
0344.16 [S-]
0344.59 [S-]
0345.50 [S-]
0347.01 [S-]
0347.43 [S-]
0347.50 [S-]
0349.10 [S-]
0349.50 [S+]
0351.20 [S+]
0351.40 [S-]
0352.00 [S--]
0352.52 [S-]
0353.20 [S-]
0354.33 [S+]
0354.34 [S-]
0356.16 [S]
0356.18 [S--]
0357.01 [S-]
0358.00 [S-]
0358.26 [S--]
0400.00 [S-]
0401.17 [S-]
0401.35 [S-]
0401.43 [S-]
0402.05 [S]
0402.29 [S-]
0402.38 [S-]
0402.57 [S-]
0403.41 [S]
0404.32 [S,S-]
0404.50 [S]
0405.19 [S]
0405.37 [S+]
0405.40 [S+]
0406.49 [S]
0407.23 [S-]
0407.29 [S-]
0407.34 [S-]
0408.03 [S-]
0408.19 [S-]
0408.22 [S-]
0408.47 [S-]
0409.04 [S]
0409.05 [S+]
0409.48 [S-]
0411.05 [S-.S-]
0411.15 [S-]
0411.15 [S-]
0412.01 [S]
0412.38 [S]
0412.45 [S--]
0412.48 [S-]
0414.00 [S]
0414.01 [S-]
0414.10[S-]
0415.15 [S]
0414.34 [S-]
0414.53 [S-]
0415.11 [S-]
0415.30 [S-]
0416.15 [S--]
0416.50 [S-]
0417.25 [S+]
0417.40 [S]
0418.30 [S-]
0418.39 [S--]
0418.40 [S-]
0419.41 [S]
0420.20 [S]
0420.53 [S-]
0420.55 [S-]
0421.12 [S-]
0421.51 [S-]
0422.42 [S--]
0422.47 [S+]
0422.58 [S]
0423.04 [S-]
0423.10 [S-]
0423.15 [S-]
0423.50 [S-]
0424.15 [S-]
0424.31 [S]
0424.44 [S]
0425.01 [S]
0425.12 [S-]
0425.20 [S]
0425.29 [S]
0425.37 [S]
0425.49 [S]
0426.01 [S-]
0426.13 [S-]
0426.20 [S-]
0426.25 [S+]
0426,47 [S-]
0427.00 [S]
0427.08 [S-]
0427.28 [S-]
0427.34 [S-]
0427.44 [S-]
0428.04 [S-]
0428.15 [S-]
0428.35 [S-]
0428.35 [S-]
0428.43 [S-]
0428.55 [S-]
0428.59 [S]
0429.10 [S]
0429.20 [S-]
0429.28 [S]
0429.33 [S]
0430.02 [S]
0430.10 [S]
0430.11 [S]
0430.15 [S]
0430.28 [S+]
0430.36 [S-]
0430.50 [S-]
0431.05 [S-]
0431.26 [S-]
0431.31 [S-]
0431.50 [S+]
0439.09 [S-]
0432.15 [S-]
0432.26 [S-]
0432.56 [S-]
0433.16 [S]
0433.17 [S+]
0433.30 [S-]
0434.13 [S]
0434.28 [S-]
0435.05 [E?]
0435.17 [S]
0436.27 [S+]
0437.07 [S]
0437.32 [S--]
0437.40 [S-]
0437.56 [S]
0437.57 [S+]
0438.24 [S]
0439.12 [S-]
0439.13 [S+]
0439.33 [S-]
0439.38 [S--]
0440.00 [S+]
0440.42 [S-]
0441.37 [S-]
0442.06 [S+]
0442.33 [S--]
0442.22 [S-]
0443.19 [S-]
0443.30 [S]
0443.51 [S-]
0444.07 [S]
0444.17 [S-]
0444.56 [S,S-]
0445.15 [S]
0445.23 [S-]
0445.31 [S]
0446.16 [S-]
0446.40 [S]
0447.48 [S-]
0448.31 [S-]
0449.14 [S]
0449.17 [S]
0449.57 [S-]
0450.06 [S]
0450.32 [S-]
0452.04 [S]
0452.09 [E]
0452.39 [S-]
0452.48 [S-]
0452.57 [S]
0453.32 [S]
0454.08 [S]
0454.12 [S]
0454.23 [S]
0454.40 [S]
0455.06 [S]
0455.29 [S]
0455.54 [S]
0456.04 [S]
0456.23 [S]
0456.29 [S]
0457.04 [S]
0457.52 [S]
0458.44 [S]
0458.57 [S]
0459.35 [S]
0500.40 [S]
0500.45 [S]
0501.24 [S]
0502.27 [S]
0502.49 [S]
0502.59 [S]
0503.27 [S]
0503.29 [S]
0503.54 [S]
0504.00 [S]
0504.05 [S]
0505.08 [S]
0505.36 [S]
0505.40 [S]
0506.35 [S]
0506.56 [S]
0507.03 [S]
0507.16 [S]
0507.41 [S]
0507.45 [E]
0507.55 [S]
0508.13 [S]
0508.34 [S]
0508.42 [S]
0508.55 [S]
0509.38 [S]
0509.57 [S]
0510.00 [S]
0510.18 [S]
0510.40 [S-]
0511.06 [S]
0511.57 [S]
0512.XX [S-]
0515.28 [M]
0515.40 [S-]
0516.17 [S-]
0517.08 [S-]
0517.59 [S-]
0518.45 [S-]
0518.48 [S-]
0419.30 [S-]
0519.38 [S]
0520.38 [S-]
0522.50 [S-]
0522.58 [S+]
0524.10 [S-]
0525.28 [S-]
0525.59 [S-]
0527.17 [S-]
0527.37 [S]
0528.55 [S-]
0529.26 [S-]
0529.31 [S]
0530.19 [S-]
0531.01 [S]
0532.10 [S-]
0533.30 [S-]
0533.40 [S-]
0534.07 [S-]
0535.46 [S-]
0535.59 [S-]
0536.10 [S-]
0536.31 [S-]
0537.35 [S-]
0538.35 [S-]
0539.20 [S--]
0540.50 [S-]
0541.55 [S-]
0542.53 [S-]
0543.25 [S-]
0544.30 [S-?]
0546.25 [S-]
0547.13 [S+]
0547.23 [S]
0548.20 [S-]
0550.37 [S]
0551.00 [S-]
0551.33 [S--]
0552.41 [S+]
0554.40 [S-]
0554.41 [S-]
0556.20 [S-]
0556.21 [S--]
0556.31 [S--]
0558.55 [S-]
0600.38[S+S+]
0602.09 [S,S]
0602.45 [S]
0603.05 [S-]
0603.39 [S-]
0604.13 [S--]
0605.30 [S+]
0606.18 [S-]
0608.30 [S-]
0610.00 [S--]
0610.30 [S+]
0615.50 [S-]
0616.16 [S--]
0617.16 [S---]
0617.56 [S+]
0618.67 [S---]
0619.45 [S+]
0620.45 [S-]
0621.50 [S---]
0622.35 [S+]
0624.50 [S-]
0626.10 [S-]
0627.00 [S-]
0629.20 [S-]
0629.21 [S-]
0629.58 [S--]
0632.46 [E]
0634.12 [S-]
0635.55 [S]
0636.31 [S---]
0637.06 [S-]
0637.58 [S--]
0638.10 [S-]
0639.30 [S--]
0640.05 [S]
0642.38 [S]
0644.44 [S--]
0646.23 [S+]
0646.32 [S--]
0646.46 [S]
0646.47 [S]
0646.48 [E]
0649.99 [S--]
0650.45 [S,S+]
0651.47 [S--]
0653.05 [S--]
0653.35 [S-]
0656.31 [S-]
End of Tape
0657.11 [S?]
0658.59 [S+]
0659.01 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Afternoon storms with severe weather moved off the Front Range into southeast CO and then KS. Several tornado watches out north of stationary from TX to MO. MEaPRS heads north into northern OK and southern KS, along with sub-VORTEX crews. CO system moved as a NE-SW line with trailing stratiform into western KS while many supercells in southern KS merged into an MCC after dark. The entire storm system began dissipating by 0600, with the heavy weather (and sprite sounds?) moving into MO. Very hard to see TLEs due to debris clouds and high boundary layer humidity. Did get a number of clear shots however along with quite a few seen through clouds layers. Several FORTE passes. About ten NSSL E-field balloons. No LANL balloon. P3 missions. No moon. Very good star field once debris clouds evaporated.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)=Meteor JD 98145 25MAY98 0332 Start obs 0734 End obs0332.02 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Afternoon storms with severe
weather moved off the Front Range. Tornado watches the entire length of the
Rockies. Relatively little severe weather resulted however and most of the cells
began to decrease with sunset. We track one cell (75%) positive into western
Nebraska. It was about 15,000 km2, but produced no sprites. A smaller cell (maybe
5000 km2 radar echo) in the Black Hills did suddenly develop sprites. We viewed
the last 45 minutes of its life, and it was spriting until the last +CG. They
were small but bright c-sprites. No elves. A larger system in north Texas may
have been making sprites but could not see anything with smoke and lights of
Denver. No moon. FORTE pass. Good star field once debris clouds evaporated though
still some forest fire smoke preventing low elevation monitoring.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98147 27MAY98 0258 Start obs 0542 End obs0424.50 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Another high rate sprite storm. Cells moved off the Foot Hills during afternoon, and grew as they moved east into Nebraska and into some much higher theta-e air. Once again, very high percentage of positives (above 50% most of time). A S-box was issued by SPC after 0300 UTC. Two cells gradually merged, first in cirrus anvil and second on radar. Also massive system in Iowa - which produced some sprites at 750 km that were visible peaking over tops of Nebraska storms. One FORTE pass. New moon setting, not much of a factor. The northern most part of the system produced the most sprites - which were visible at twilight. Many of the sprites were partially masked by cirrus clouds. The southern end of the storm only produced a few bright carrots late in its life cycle. The sprites ended with a "bang" a huge elve at 0447. Though the lightning rate was still rather high with a lot of positives, saw none after 0500 - it is possible some were masked by thin cirrus. Good star field once debris clouds evaporated but there was still some background aerosol from the Central American fires.
(S)=Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98149 29MAY98 0259 Start obs 0600 End obs0306.36 [S--]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Two small supercell hailstorms formed at dark in western NE and southwest SD. They were 200-375 km out. SPC issues a S-box for the area until 0900Z. Thick cirrus riding the subtropical jet was streaming over the area, but conveniently dissipated in subsidence going over the mountains, so we were able to get fairly good shots at the near field cell. It had hail, 71dBZ, tops to 55000 ft., and may have been a right mover. We could see pretty active lighning from YRFS. The IC/CG ratio was high, possibly above 20. The cell was more than 50% positive, though the CG rate ws not that high. The radar area probably was not much more than 5000-7500 km2. Two carrot sprites were all that were noted. The new moon was mostly lost in cirrus cloulds. Good star field once debris clouds evaporated but there was still come background aerosol from the Central American fires.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98150 30MAY98 0330 Start obs 0600 End obs0351.34 [S]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Polar high still dominates central U.S., but a return of tropical air up the Front Range along with a 100 mph subtropical jet over the central US caused numerous tornado and severe t-storm watches to be issued along the High Plains. But the resulting weather was fairly muted. MEaPRS deployed to Salina, KS but could not intercept. A large, rather disorganized MCS formed in Nebraska, oriented west to east through the southern part of the state. Flash rates were modest and % positive was 10-16% Upslope from low in eastern CO kept clouds in around YRFS. Did get some breaks from time to time and saw 11 sprites between 0304 and 0449 UTC. There were probably more. No FORTE passes during evening. Nearly full moon made for rather bright sky along with high humidity.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98150 08JUN98 0301 Start obs 0452 End obs0305.20 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Thunderstorms developed over the foothills during the afternoon and moved northeast across the Denver area to NE Colorado. Initially, storms in NE colorado produced little lightning and the storms south of Rapid City, near Scottsbluff, NE, were the most prolific. After dark, the storms NE of Denver intensified and produced almost continuous lightning for several hours. Ran a plunix camera with ms timing to see the CG channels. During this period, they maintained a distance of about 100km from YRFS. A storm system in far NE Colorado and Nebraska, west of North Platte was nearly all positive, but could not be seen due to the debris clouds from the closer convection. After about 6z, the debris clouds started to clear, and sprites were observed shortly thereafter. Some were from the storm at 200km, and were seen through thin clouds. Others were at distances of 80 to 150km, and were above the clouds at an elevation of 30-50+ degrees. Some appeared to be larger than the wide angle lenses (50 degree horizontal fov) at YRFS. Nearly continuous in cloud and cloud-to-ground discharges made visual observations difficult. Operations ended at 0815z when fog started forming in eastern Weld county, blocking the view. Three systems (SD, NE/CO, and KS) were in the process of merging at the conclusion of operations. Sprites were probably being produced by the NE/CO storms prior to observation because of the debris clouds. Sprites were observed in the SD storms at over 200km earlier, but efforts were concentrated on the close storms.
Solo operations, Walt in Chicago, Tom alone. ELF sampled on fast card with U of M photometer. VLF sampled on slow card with U of M photometer. ELF signal was unfiltered (approx. 1-1000hz). Noise on VLF was minimal.
NLDN data saved as 23Jun98A and 23Jun98B.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98174 23JUN98 0300 Start obs 0815 End obs
05:07:00 S?
05:22:52 Spider (Labview samples)
05:23:44 "
05:25:29 "
05:26:55 "
05:27:23 "
05:28:31 "
05:28:57 "
05:30:07 "
05:30:31 "
05:31:16 "
05:36:25 "
05:41:22 "
06:55:26 Sprite
06:55:40 Sprite? thru cloud?
06:56:13 S
06:56:53 S
06:57:46 S
07:00;0? S
07:06:00 S
07:07:56 S
07:09:43 S
07:10:24 S
07:10:55 S
07:12:00 S?
07:12:41 S
07:13:00 S
07:13:14 S
07:13:32 S?
07:14? S?
07:15:10 S
07:15:50 S
07:17:23 S
07:17:30 S
07:18:53 S
07:19:56 S Lab
07:20:13 S
07:20:34 M
07:21:18 S
07:22:23 S
07:28:28 S
07:29:32 S
07:30:10 S Lab
07:30:13 S Dim
07:31:26 S Lab
07:31:36 S
07:32:11 S
07:32:43 S
07:33:24 S Lab
07:33:50 S Lab
07:34:15 S
07:34:45 S Lab
07:35:15 S
07:35:42 S Lab
07:35:55 S
07:36:19 S++ Lab Dancer
07:37:20 S
07:37:45 S+++ Lab
07:38:36 S
07:38:58 S Lab
07:39:21 S
07:39:29 S Lab
07:40:10 S Dim
07:40:28~ S
07:41:46 S Lab
07:43:47 S
07:45:25 S
07:47:02 S Lab
07:48:17 S Lab
07:48:44 S Lab
07:50:06 S Lab
07:51:53 S
07:52:13 S
07:53:58 S
07:55:11 S Lab
07:56:51 S Lab
07:57:45 S Lab
07:58:38 S+ Lab
08:00:02 S Lab
08:02:57 S+ Lab
08:03:49 S
08:05:33 S
08:11:47 S Lab
SPRITES'98 PRELIMINARY SPRITE LOG
JD 98196
15 JULY 1998
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Heat wave continues (third straight day 100F) with convection suppressed. A few dry thunderstorms did move off the Front Range into the Plains during the afternoon and a few survived to become small supercells. Along a weak frontal boundary in western NE, a small cell after 0300 had quiet a few positives. It was a right moving hail supercell (Top 500). It and several other supercells were not observed making any sprites between 0400 and 0420, when suddenly the NE cell (400 km range) started spriting (small smudges and comb types). The storm was already in its weakening phases. It appears that the last handful of CGs were all positives, and most made sprites (this over a 25 minute period). The cell was not much more than 8000 km 2. This behavior has been seen before. What happens during storm collapse to make +CGs that induce sprites?
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98196 15JUL98 0402 Start obs 0602 End obs0402.xx [S]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Heat wave continues, but with convection a bit more active. A squall-line-like group of thunderstorms formed over the Front Range during mid-afternoon, spawning a few small tornadoes. There were no watches issued however. The system moved slowly in northeast Colorado after dark, but smaller cells lingered behind making viewing difficult. As it lost its severe characteristics the percent positive also dropped. A few sprites were send through the clouds. There was evidence of some very large and long lasting (2000 ms plus) spider discharges. Smaller, mostly negative, cells also formed down south of Denver but produced no sprites as would be expected.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98197 16JUL98 0313 Start obs 0515 End obs0340.07 [S]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Heat wave continues. No local storms. Watched severe storm in SD and MN move eastward (tornado watch issued). Could occasionally see dim sprites near horizon at ranges beyond 600 km. Though sky was quite clear, there was just enough aerosol to limit ultra-long range viewing. No moon. Two FORTE passes. Small storm in WY around 0600 did not produce anything.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98200 19JUL98 0306 Start obs 0630 End obs0356.00 [S--]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Heat wave continues. No local storms. Small cells drifted out of Wyoming into western SD at sunset into higher theta-e air and grew for a while. Several cells on radar shared a common cloud canopy and composite reflectivity showed much more connectedness than base reflectivity. MCS size maybe 15,000 km2 max. Rates 500-600/hr and running 5-15%. Sprites actually lulled when percent +CG rose. Excellent viewing. Few clouds, no moon. Many sprites- combs or c-sprites. Closest were 350 km from a tight little cell. Little blue shows up on isocons or PMTs. Nice airglow layers after 0500 over storm! Wind shift from outflow actually reaches YRFS and drops temperature 16 in ten minutes.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98201 20JUL98 0300 Start obs 0730 End obs0347.17 [S+]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Upslope cloudiness and cool weather continues. Upslope clouds limit viewing. Convective development along Front Range during afternoon generally weakens soon after sunset. Cluster of storms in southeast CO move into western Kansas and slowly built in area and strength until around 0600, after weak weakening was in evidence. Never very high percent positive +CGs, under 10% much of time. Heard some VLF signatures. Saw three sprites through thin spots in clouds. EXL aircraft flew storm. Reported sprite at 0645.40. FORTE passes at 0411 and 0557 Z at time of sprites. No moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98205 24JUL98 0330 Start obs 0645 End obs0547.48 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Upslope cloudiness and cool weather continues. Convective development along the Front Range during the afternoon moves east, causing flash flooding. Major cell after sunset in east central CO, very high percentage of +CG's for a time. Cell gradually lost positives while strengthening up until about 0600. Saw a number of sprites through clouds. Then weakened as mail center of convection moved to east-west line through Kansas. Clouds obscured viewing after about 0630x. FORTE passes at 0509z at time of sprites. No Moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98207 26JUL98 0310 Start obs 0700 End obs0355:xx [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Spectacular display of sprites from MCS which formed in Texas/Oklahoma panhandle area and slowly moved north-northeast during the night. It has a fairly high flash rate but percent +CG's stayed below 10% most of the time. The system was not very large (15,000 km2). A series of huge complex carrots, some with elves, were imaged. They were very regular, and then suddenly stopped as the radar echo changed characteristics. The viewing was exceptionally good and clear images were obtained at 500-600km. FORTE passes at 0445 and 0627z at time of sprites. No Moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98208 27JUL98 0410 Start obs 0813 End obs0424:40 [S]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Few storms over Plains. One cell forms in Texas/Oklahoma panhandle, similar to the night before, and moves slowly north-northeast. Flash rate moderate, but percent +CG's generally under 10%. Thin cirrus partially blocked view. Saw half dozen sprites through clouds. FORTE passes at 0416 and 0603z at time of sprites. No moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98209 28JUL98 0403 Start obs 0606 End obs0353:13 [S]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Scattered small MCS over mountains and plains during evening. One cell in extreme SE Colorado was marginal. Directly in between it and YRFS was a second storm at 200km that produced numerous CF's. Saw few very skinny C-sprites. Not sure if they came from the near or far field storm. Most of the time clouds from the near storm blocked the view of the far system. Also looked at WY/SD cells after 0600z, but saw little. FORTE passes at 0330 and 0504z. No moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98210 29JUL98 0323 Start obs 0700 End obs0420:29 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Upslope conditions return. Several complex MCS's form in eastern CO and KS, with rather high flash rates and positive percents above 10%. Sprites expected, but viewing somewhat restricted by debris clouds. Obtaines a rash of bright sprites from storms, possibly at several ranges, before clouds and rain moved in, forcing emergency shutdown. FORTE passes at 0331 and 0516z. Half moon in west during observations.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98211 30JUL98 0305 Start obs 0430 End obs0315:52 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
No meteorological writeup available.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98213 01AUG98 ???? Start obs ???? End obslogsheet not available, sprites were seen from CO/KS MCS.
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Strong thunderstorms formed along the Front Range and moved east. Long, north-south MCS moved into western KS and NE after dark. Lingering low level clouds make viewing difficult. Many meteors including one very bright bolide. Number of rather bright carrot sprites through clouds. Tohoku saw many elves (30+) after 0800z. FORTE passes at 0419z. Sprites and elves were sporatic all night. Storm flash rate and percent positive fluctuated most of the night. 3/4 moon.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98214 02AUG98 0245 Start obs 0700 End obs0324:10 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Strong thunderstorms form along the Front Range and move east. Low clouds linger behind. Watched display of CG's at 100 to 200 km with high-speed camera. Many spider type discharges and continuing currents. As low clouds finally cleared, saw last half hour (EOSO phase) of small (less than 10000km2) MCS in southeastern CO. Made several sprites, including one spectacular one (got on Kodak). Not sure about FORTE pass. Full moon and brilliant Jupiter. LANL tracker and U of M not co-mounted. A lot of moon noise? LANL could not tilt high enough with tracker due to obstruction.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98221 09AUG98 0239 Start obs 0645 End obs0605:34 [S-]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Very strange case. Long MCS formed in SE Colorado into western KS and into SW Nebraska persists for several hours after sunset. Percent positive above 10%, moderate flash rates, and generally excellent viewing. Yet NO sprites. May have seen a few elves in dying phase. Really cannot explain why? Perhaps the stratiform region was just not large enough? Had been some severe WX warnings off the Front Range earlier in the day, but no watches issued for this system later. Cloud canopy not exceptionally cold, but not that warm either. Full Moon may have hindered seeing some of the dim sprites, but that can't be main reason. Some meteors.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98222 10AUG98 0250 Start obs 0700 End obs0310:15 [E]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Another very strange case. Long MCS from TX panhandle into western KS and into southwestern NE persists for several hours after sunset. Percent positive well above 10%, moderate flash rate, and generally excellent viewing. Yet NO sprites. Cloud canopy not cold, so is that the factor?? Full Moon may have hindered viewing some of the dim sprites, but that can't be the main reason. Some meteors. No good FORTE passes. Did get some EOSO sprites and one elve near end of period from TX cell, but main area of convection did nothing...why?
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98224 12AUG98 0230 Start obs 0630 End obs
0440:xx
[S-]
0443:55 [S]
0451:51 [S-]
0513:30 [E]
The following is a very preliminary listing of the times of sprites imaged at the Yucca Ridge Field Station. These are based solely on real-time visual inspection of the video monitoring system. There are most likely some additional sprites not listed and not all those below may in fact be sprites. All times are UTC. Times are likely to be within ±5 seconds of actual time.
Moderate MCS in SE Colo and W Kansas with smaller cells extending NE into Kansas. View partially obscured by thin clouds, but after a while sprites started showing through. The storm had moderate flash rates and +CG percentages ranged from 5-30%. Went through classic sequence of diet sprites to big bombs at regular intervals when it suddenly stopped cold! No elves. No moon. Kodak high speed video. Great shot at 0428z.
(S)= Sprite (E)= Elve (B)= Blue Jet (CF/CG)= Cloud/Ground flash (M)= Meteor JD 98237 25AUG98 0230 Start obs 0532 End obs03xx:xx [S-]