April 12, 2002: Convective cells w/ heavy rain and hail Author: Pam Heinselman, CIMMS/OU Last Updated: 21 April 2003

Forecast/Weather:

On 12 April 2002, a north-to-south-oriented line of convective cells moved over southern Oklahoma. Some of the cells produced heavy rain and hail (confirmed by reports from a spotter and sheriff).

Radar Operations:

Start time: 15:43 4/12/02 UTC (09:43 4/12/02 local time)
Stop time: 19:53 4/12/02 UTC (13:53 4/12/02 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Cold season

Operational Delivery:

Not applicable.

Snapshots:

An example of a polarimetric hail signature is shown below for 16:34 UTC 12 April 2002. Near this time, a sheriff, and spotter reported 1" hail. The cell of interest is located over southwest Stevens County. Hail is suspected in the area of minimum ZDR, RhoHV, and KDP, and maximum reflectivity.

Figure 1: Reflectivity at 16:37 UTC 12 April 2002.	Figure 2: Differential reflectivity at 16:37 UTC 12 April 2002.
Figure 3: Correlation coefficient at 16:37 UTC 12 April 2002.	Figure 4: Specific differential phase at 16:37 UTC 12 April 2002.