August 24, 2002: Convective Cells, Gust Fronts, AP, and Insects Author: Pam Heinselman, CIMMS/OU Last Updated: 18 April 2003

Forecast/Weather:

On 24 August 2002, convective cells develop north of KOUN, with their downdrafts creating outflow boundaries that move over KOUN (GF1, 3:45-8:36 UTC; GF2, 11:14-16:58 UTC; GF3, 15:25-18:01 UTC). Insects are lifted above these outflows but new cells fail to develop. Throughout the period, insects are likely observed around KOUN. The first round of covective cells and their gust fronts are shown in the first column of snapshots. Notice that the specific differential phase is unaffected by biological scatterers and interference, and that differential phase and the correlation coefficent have different signatures for precipitation and biological scatterers, along the gust front and south of KOUN. The second column of figures shows the band of insects lifted by the gust front as it moves past KOUN and the onset of AP behind it. Again, the specific differential phase is unaffected by biological scatterers and AP. The third column shows the last area of precipitation to develop on 24 August, along with the next set of gust fronts, an area of biological scatterers southwest of KOUN w/ embedded AP, and possibly a mix of AP and precipitation NE of KOUN.

Radar Operations:

Start time: 02:41 8/24/02 UTC (21:41 8/23/02 local time)
Stop time: 19:04 8/24/02 UTC (14:04 8/24/02 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Cold season

Operational Delivery:

Not applicable.

Snapshots:

Figure 1: Reflectivity at 4:35 24 August '02.

Figure 2: Reflectivity at 7:33 24 August '02.

Figure 3: Reflectivity at 12:27 24 August '02.

Figure 4: Differential reflectivity at 4:35 24 August '02.

Figure 5: Differential reflectivity at 7:33 24 August '02.

Figure 6: Differential reflectivity at 12:27 24 August '02.

Figure 7: Correlation coefficient at 4:35 24 August '02.

Figure 8: Correlation coefficient at 7:33 24 August '02.

Figure 9: Correlation coefficient at 12:27 24 August '02.

Figure 10: Specific differential phase at 4:35 24 August '02.

Figure 11: Specific differential phase at 7:33 24 August '02.

Figure 12: Specific differential phase at 12:27 24 August '02.

Figure 13: Hydrometeor classification at 4:35 24 August '02.

Figure 14: Hydrometeor classification at 7:33 24 August '02.

Figure 15: Hydrometeor classification at 12:27 24 August '02.