May 14, 2003: Convective Cells w/ Large Hail Author: Pam Heinselman, CIMMS/OU Last Updated: 20 May 2003

Forecast/Weather:

On 14 May 2003, several severe convective storms developed between 3-17 UTC. The most significant hail signatures were associated with storms located south and southeast of KOUN during the early morning, from about 8-11:30 UTC (see Figs. for examples). Hail signatures were also seen in the ~twice hourly available products at 3:22 and 6:57 UTC west of KOUN, and at 16:35 and 17:07 UTC east-southeast of KOUN (see Figs. for examples).

Radar Operations:

Start time: 03:22 5/14/03 UTC (10:22 5/13/03 local time)
Stop time: 18:07 5/14/03 UTC (13:07 5/14/03 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Warm season

Operational Delivery:

TBD.

Snapshots:

Polarimetric hail signatures are observed at 6:57 UTC at 286 deg 44.95 km from KOUN. Note the ZDR hole associated with high reflectivity values at the 0.5 deg elevation.

Figure 1: Radar reflectivity at 6:57 UTC 14 May 2003.

Figure 2: Differential reflectivity at 6:57 UTC 14 May 2003.

Series of snapshots taken during long-lived severe storm event (~8-11:30 UTC), showing examples of polarimetric hail signatures at the 0.5 deg elevation.

Figure 1: Radar reflectivity at 8:34 UTC 14 May 2003. Cells of interest are located at 174 deg 58 km and 187 deg 48 km.	Figure 2: Differential reflectivity at 8:34 UTC 14 May 2003. Cells of interest are located at 174 deg 58 km and 187 deg 48 km.
Figure 3: Radar reflectivity at 10:13 UTC 14 May 2003. Cells of interest are located at 155 deg 62 km and 163 deg 98 km.	Figure 4: Differential reflectivity at 10:13 UTC 14 May 2003. Cells of interest are located at 155 deg 62 km and 163 deg 98 km.
Figure 5: Radar reflectivity at 11:18 UTC 14 May 2003. Cells of interest are located at 144 deg 92 km and 153 deg 82 km.	Figure 6: Differential reflectivity at 11:18 UTC 14 May 2003. Cells of interest are located at 144 deg 92 km and 153 deg 82 km.

Polarimetric hail signatures, observed at 16:35 UTC at 114 deg 53 km from KOUN. Note the ZDR hole associated with high reflectivity values at the 0.5 deg elevation.

Figure 1: Radar reflectivity at 16:35 UTC 14 May 2003.

Figure 2: Differential reflectivity at 16:35 UTC 14 May 2003.