June 13, 2002: Two Squall Lines with AP (some embedded) and Biological Scatterers Author: Pam Heinselman, CIMMS/OU Last Updated: 28 April 2003

Forecast/Weather:

On 13 June 2002, the strong convective cells from the 12th evolve into a squall line with some cells producing heavy rain. There are hail signatures in the first few volumes. Anomalous propagation occurs around KOUN following the passage of the squall line (3:36-12:58 UTC), while biological scatterers are disturbed by the gust front (3:36-6:04 UTC, see Figs. 2-3,5-6, 8-9, 11-12). A second squall line develops in northwestern Oklahoma around 9:23 UTC. This convective line of cells moves southeastward across Oklahoma, and anomalous propagation occurs behind it (17:32-18:34). Some of the AP is embedded within precipitation.

Radar Operations:

Start time: 00:02 6/13/02 UTC (19:02 6/12/02 local time)
Stop time: 19:48 6/13/02 UTC (14:48 6/13/02 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Cold season

Operational Delivery:

Not applicable.

Snapshots:

The convective cells from 12 June evolve into a squall line, reaching its mature stage by 5:02 UTC (Fig. 3). Polarimetric signatures indicate AP behind the line and biological scatterers ahead of it, owing to lift above the gust front (columns 2&3). The KDP is unaffected by these anomalous scatterers.

Figure 1: Reflectivity at 02:19 UTC 13 June 2002.

Figure 2: Reflectivity at 3:46 UTC 13 June 2002.

Figure 3: Reflectivity at 5:02 UTC 13 June 2002.

Figure 4: Differential reflectivity at 02:19 UTC 13 June 2002.

Figure 5: Differential reflectivity at 3:46 UTC 13 June 2002.

Figure 6: Differential reflectivity at 5:02 UTC 13 June 2002.

Figure 7: Correlation coefficient at 02:19 UTC 13 June 2002.

Figure 8: Correlation coefficient at 3:46 UTC 13 June 2002.

Figure 9: Correlation coefficient at 5:02 UTC 13 June 2002.

Polarimetric signatures indicate AP north of KOUN, biological scatterers southeast of KOUN, and stratiform precipitation with a bright band over southeastern Oklahoma. This precipitation marks the exodus of the earlier squall line out of Oklahoma.

Figure 1: Reflectivity at 08:58 UTC 13 June 2002.	Figure 2: Differential reflectivity at 8:58 UTC 13 June 2002.
Figure 3: Correlation coefficient at 8:58 UTC 13 June 2002.	Figure 4: Specific differential phase at 8:58 UTC 13 June 2002.

Figure 1: Reflectivity at 13:35 UTC 13 June 2002.	Figure 2: Differential reflectivity at 13:35 UTC 13 June 2002.
Figure 3: Correlation coefficient at 13:35 UTC 13 June 2002.	Figure 4: Specific differential phase at 13:35 UTC 13 June 2002.

Figure 5: Differential reflectivity at 3:46 UTC 13 June 2002.

Figure 6: Differential reflectivity at 5:02 UTC 13 June 2002.

Figure 7: Correlation coefficient at 02:19 UTC 13 June 2002.

Figure 8: Correlation coefficient at 3:46 UTC 13 June 2002.