SPRITES 99 YUCCA RIDGE FIELD STATION
FMA Research


JD 99230 18 AUGUST 1999
PRELIMINARY SPRITE LOG

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.


SUMMARY: Spectacular sprites from a large MCC. Forecast models correctly predicted the formation of an MCC in northeast Colorado along the old frontal boundary, aided by upslope flow, a short wave trough aloft, and some monsoon moisture at lower levels. SPC issued a severe thunderstorm watch for the CO/NE region. By sunset the system was approaching the Nebraska border, and characteristically had high positive percentages (above 40%). Heavy rains caused flooding in northeast CO. Softball size hail was reported in NE later. Reflectivities were above 65 dBZ for several hours. Cloud top temperatures were colder than 75C, and flash rates were above 4000 fl/hr for several hours. The percent positives fell steadily as the storm matured, and they moved into the large trailing stratiform region. Sprites were visible as soon as the LLTVs were turned on, though some debris stratocumulus restricted viewing for the first hour. The was a quarter moon setting in the west which caused some sky brightness. The viewing was exceptionally clear otherwise, with stars at 2-3 degrees above horizon. Many of the sprites were exceptionally bright, some being clearly visible (salmon colored) to the naked eye from Yucca Ridge at 500 km range. The MM5 model forecast run ran without problems.

There were five elves associated with apparent negative CGs [-E]. Four events were associated with apparent "troll events" (T). Also included are the NLDN peak currents (kA) of the most likely stroke to be the parent of the TLE. ND means no candidate stroke detected.

Total TLEs from Yucca Ridge This Campaign: 1735 

(S) = Sprite;  (E) = Elve;  (B) = Blue Jet;  (CF/CG) = Cloud/Ground flash;  (M)=Meteor


JD 99230   18 AUGUST 1999

DATA WERE REVISED ON 12-7-99

Times listed are for the start of the 

CCD integration period.  Add 16.7ms for

the finish of this period.


0220.		Start LLTV Observations 

0231.38.826	[S]	2/1/3 	   +106

0239.42.378	[S]	4/3/1	   +134

0241.42.165	[S]	6/4/2	   +50

0244.47.384	[S]	4/1/1      +85

0246.32.273	[S]	7/2/2      +26

0248.57.251	[S]	4/2/1	   +77

0249.49.672	[S]	5/3/1	   +92

0252.37.356	[S]	9/1/3	   +27

0252.45.514	[S]	8/3/2	   +66

0253.09.638	[S]	1/1/1	   +44

0253.11.708	[S]	6/2/1	   +119

0254.29.679	[S]	5/1/2	   +80

0254.32.171	[E,S]	2/1/4  +144

0255.12.628	[S]	5/2/2	   +79

0256.56.583	[S]	8/1/5	   +69

0304.04.612	[S]	19/2/5	   +33

0308.28.093	[S]	10/3/4	   +26

0308.28.444	[S]	5/1/4	   +47

0311.31.861	[S]	8/1/1	   ND?

0311.32.128	[S]	5/2/4	   +59

0314.57.701	[S]	2/1/3	   +29

0314.58.909	[E]	1/1/3	   ND

0317.29.403	[S]	3/1/2	   ND

0318.11.245	[S]	6/1/2  	   ND

0318.11.396	[S]	7/5/2	   +42?

0325.06.596	[-E]	1/1/1  -98

0328.08.996	[S]	4/1/2	   +137

0335.45.954	[E]	5/1/4	   +95

0336.38.407	[S]	3/1/4	   +84

0336.38.690	[S]	2/1/1	   +66

0338.07.897	[S]	2/1/1	   +52

0341.08.929	[S]	4/1/1	   +53

0346.31.285	[E]	1/1/1	   +99

0350.56.752	[E]	1/1/1	   +100

0353.28.955	[E]	1/1/3	   +151

0358.00.494	[S]	3/1/3	   +59

0409.26.416	[S]	2/1/3	   +105

0415.08.292	[S]	1/1/1	   +147

0419.14.173	[S]	3/2/4	   +47

0419.27.870	[E]	1/1/1	   ND

0423.31.531	[S]	5/1/2	   +24

0424.13.740	[S]	4/1/2	   +104

0428.09.727	[S]	2/1/1	   +116

0430.28.402	[S]	1/1/2	   ND

0430.29.500	[-E]	1/1/1  -69

0431.52.667	[S]	6/3/1	   +40

0436.09.225	[S]	4/1/5	   +75

0436.40.589	[E]	1/1/3	   +109

0438.42.745	[S]	4/1/3	   +24

0441.10.744	[E,S]	6/1/2  +51

0442.30.724	[S]	4/1/3	   +42

0444.03.934	[-E]	1/1/2  -94

0445.21.065	[S]	4/1/3	   ND

0446.47.665	[S]	4/1/2	   +60

0449.24.322	[S]	4/1/4	   +49

0457.39.352	[S]	3/1/1	   +35

0458.14.221	[E,S]	1/1/2  +73

0458.14.237	[S]	1/1/3	   ND

0459.31.047	[E,S]	4/1/5  +69	

0502.05.653	[E,S]	3/1/5  +61

0505.47.542	[S]	5/1/4	   +77

0508.07.115	[S]	4/1/5	   +68

0510.05.585	[E]	1/1/1	   +78

0510.05.601	[S]	6/1/4	   ND

0510.38.585	[S]	4/1/5	   +55

0510.38.667	[S]	4/1/5	   +84

0510.39.101	[ST]	10/7/5 +44

0514.13.200	[S]	4/1/5	   ND

0514.13.416	[E,S]	4/1/5  +28

0515.53.517	[-E]	1/1/2  -87

0517.15.265	[S]	4/2/2	   +48

0517.16.533	[S]	8/1/4      +72

0519.18.640	[S]	4/1/5	   +97

0523.37.131	[-E]	1/1/1  -74

0524.22.794	[S]	6/2/5	   +26

0524.22.911	[S]	5/1/5	   +68

0524.22.977	[S]	2/1/4	   +24

0524.23.311	[S]	4/1/5	   +102

0527.24.527	[S]	6/1/4	   +34

0527.24.737	[S]	5/2/1	   ND

0531.33.610	[S]	4/1/5	   ND

0536.13.891	[S]	4/1/4	   +69

0536.14.475	[E]	1/1/1	   +109

0536.15.276	[S]	9/1/5	   +54

0536.15.309	[S]	3/1/5	   ND

0536.16.177	[ST]	3/1/4  +40

0543.41.265	[E]	4/1/1	   +76	

0543.41.390	[S]	4/1/1	   +22

0543.41.507	[S]	3/1/3	   +52

0545.05.041	[S]	2/1/4	   +129

0545.05.141	[S]	2/1/4	   ND

0545.05.191	[S]	5/1/4	   ND

0548.12.229	[S]	4/1/5	   +80

0552.00.641	[E,S]	3/1/3  +137

0553.20.087	[E,S]	4/1/3  +106

0555.58.746	[ST]	13/6/4 +70

0557.15.941	[E,S]	4/1/3  +75

0557.16.391	[S]	3/1/4	   +71

0559.00.530	[E]	1/1/2	   +138

0604.15.045	[E,ST]	10/2/3 +56

0611.22.857	[S]	2/1/1	   +34

0611.23.107	[E,S]	2/1/3  +52

0615.07.666	[E,S]	4/1/5  +84

0620.10.020	[S]	3/1/2	   +53

0622.00.413	[E]	1/1/1	   +66

0622.00.430	[S]	1/1/3	   ND?

0625.26.921	[E,S]	4/1/5  +95

0630.08.320	[E]	1/1/1	   +173

0630.14.726	[S]	3/1/2	   +50

0632.07.773	[S]	3/1/4	   +126

0643.52.984	[S]	2/1/1	   +50

0649.54.893	[S]	1/1/1	   +126

0700.12.796	[S]	2/1/3	   +101

0705.27.529	[S]	2/1/1	   +20

0710.04.006	[S]	2/2/1	   +66

0725.50.822	[E]	1/1/1	   +99

0801 	End LLTV Observations