Storm Descriptions
June 11, 2000
An asymmetric mesoscale convective system (MCS), a large organized convective weather system that lasts for several hours and is comprised of a number of individual thunderstorms, approached the area from the west. The system produced numerous -CG and +CG lightning _ inch hail at 2143 UTC was reported. A well defined gust front produced gustnadoes and had peak outflows up to 50 knots. The system studied was one of three MCS that developed along a north-south line. Figure 3 shows the development on June 11 with the researched storms circled and labeled. Following is a brief description of each storm.

Figure 4: NIDS images on June 11 at 2030, 2100, and 2130 UTC

2030-2225* (J)
This storm reached a maximum reflectivity of 60 dBZ. It produced both IC and +CG lightning with initial activity shortly after development. The first CG strike was one hour and 10 minutes after the first 25 dBZ echo. At 2134 UTC, the storm had joined the MCS and had reached 60 dBZ.

2032-2140 (C)
This storm reached a maximum reflectivity of 50 dBZ and produced only IC lightning. The storm was to the north of another storm that went on to produce +CG lightning. Many weak storms formed around the area but died off rather quickly. The radar echo of 40 dBZ reflectivity stayed under 9 km in this storm. Lightning occurred late in the storm as the 50 dBZ echo appears. It originated high in the storm in 25 dBZ.

2040-2110 (B)
With a maximum reflectivity of only 35 dBZ, this storm was very short lived. It did not produce any lightning activity. Reflectivity echoes stayed under 7 km. This storm was to the south of storms D and C.

2110-2230* (D)
Maximum reflectivity of this storm was 55 dBZ. It intensified quickly with 40 dBZ reaching to 10 km. Initial lightning activity occurred during this time. The storm began to split at around 2205. The left side of the storm went on to produce -CG lightning

June 23, 2000
Storms developed in a multicellular line from southwest of Burlington, Colorado to near Goodland, Kansas. Pea to dime size hail was reported with some of these storms. The storms were -CG lightning producers and at 2120, lightning turned positive. Figure 4 shows the development on June 23 with the researched storms circled and labeled. Following is a brief description of each storm.

Figure 5: NIDS images on June 23 2030, 2100, and 2130 UTC

1935-2230*(K)
This storm produced both IC and -CG lightning. The first IC lightning was very late in the storm, 33 minutes after the first 25 dBZ radar echo. The thunderstorm formed with the line and although the first strike was negative, it later switched in polarity.

2022-2100 (E)
An isolated storm to the south of the multicellular line. It begins to dissipate at 2100 as the line strengthens and produces -CG lightning. The storm reached a maximum reflectivity of 50 dBZ. It did not intensify rapidly and initial IC stroke occurred in a low reflectivity of 35 dBZ.

2026-2135 (L)
This is an isolated storm to the east of the line. The storm reaches a maximum reflectivity of 60 dBZ. It strengthened rapidly to 50 dBZ where an IC strike occurred. It produced many -CG lightning strikes later on. Stronger echoes (of 55 to 60 dBZ) stayed under 4 km. Around 2100, the storm merged into the line.

2039-2155* (F)
This storm had a maximum reflectivity of 55 dBZ. IC lightning occurred at high altitude in 45 dBZ, seven minutes after development.. Radar top echoes could not seen from the radar scan. The storm intensified rapidly with 60 dBZ occurring at over 7 km in altitude.

2039-?*** (M)
With a maximum reflectivity of 60 dBZ, this storm produced +CG lightning about an hour after the first IC strike was detected. This storm merged with another storm (G) but remains the stronger of the two.

2041-2154 (G)
This storm started out as an isolated cell but was overpowered by another storm after which it produced +CG lightning. Maximum reflectivity was 55 dBZ and all reflectivities with the exception of 55 dBZ reached high levels in the storm. Initial lightning activity occurred at an altitude of 9.7 km.

July 12, 2000
Isolated storms developed. Several intense, quasi-stationary storms (stationary or moving very little) were responsible for hail, flooding rains, and a couple of tornadoes. Most had +CG lightning activity. Figure 5 shows the development on July 12 with the researched storms circled and labeled. Following is a brief description of each storm.

Figure 6: Radar images on July 12 at 2130, 2200, and 2300 UTC

2034-2158 (N)
This particular storm had strong updrafts during initial lightning activity. Initial IC lightning occurred just before the storm reached peak intensity. The storm reached maximum reflectivity of 60 dBZ and produced -CG lightning 18 minutes after the first 25 dBZ echo.

2224-2302** (H)
Maximum reflectivity in this storm was 55 dBZ. At 2250 this storm begins to die while cells begin to build behind it. The storm intensified quickly and reflectivities of 50 dBZ and below reached high altitudes. Lightning originated in 45 dBZ right after the storm had reached its maximum intensity. Storms to the northwest were dominated by -CG lightning, but the most northern storm remains a densely +CG lightning thunderstorm with the most production between 2300-0000.

2229-2312** (A)
This isolated storm intensified and dissipated quickly. It barely reached 50 dBZ and did not produce any lightning. The 40 dBZ reflectivity stayed below 6 km in altitude.

2253-2328** (I)
Maximum reflectivity in this isolated storm was 55 dBZ. It did not intensify rapidly and initial lightning activity occurred at low reflectivity at the early stage of the storm. This storm only produced IC lightning.

*Not the exact ending point. Due to time constraints and for purposes of this paper, some time- height diagrams were not taken to the exact ending of the storm but to a point where the storm begins to dissipate or is well part of another system.

**The time-height diagram was done on RHI scans. The program that displays the radar images is off by 1.1 km. All analysis of this storm was done to account for the 1.1 km difference in altitude, however, the diagrams do not account for this. Thus, 1.1 km should be added to each point.

***Time height diagram not included.

Time-Height Diagrams
Following are the time height diagrams for the storms studied. They are labeled as seen in Table 1.