KOUN Nighttime MCS and afternoon tornadic Event: May 16, 2003

May 16, 2003: Nighttime MCS, Biological Scatterers, and Afternoon Tornadic Event

Last Updated: 10 June 2003

Forecast/Weather:

During the night and early morning hours on 16 May 2003, an MCS moved across central Oklahoma, producing heavy rainfall in some areas. Polarimetric signatures indicate there were biological scatters around KOUN prior to this evening. Later that afternoon, convective cells formed around KOUN in association with a upper-level low. Most storms produced locally heavy showers only. However, a few cells developed supercellular characteristics, with the best observed storm producing sited tornadoes over Haskell Co. (~20-21 UTC). No hail was reported in association with these storms.

Radar Operations:

Radar/Operational Status:

Operational Delivery:

Products were delivered to the NWS. Kevin nowcast for one hail chase vehicle, manned by Mike and Pam. No hail was observed by the chasers.

Snapshots:

This first set of snapshots shows the general evolution of the night time and early morning MCS across Oklahoma. Notice that polarimetric signatures indicate some heavy rain showers occurred in association with the MCS.

Figure 1: Radar reflectivity at 06:44 UTC on 16 May 2003.

Figure 2: Radar reflectivity at 7:50 UTC on 16 May 2003.

Figure 3: Radar reflectivity at 10:00 UTC on 16 May 2003.

Figure 4: Specific differential phase at 6:44 UTC on 16 May 2003.

Figure 5: Specific differential phase at 7:50 UTC on 16 May 2003.

Figure 6: Specific differential phase at 10:00 UTC on 16 May 2003.

This set of snapshots shows a tornadic-supercell over Okfuskee Co. at 18:16 UTC and another over Haskell Co at 20:18 UTC. The Haskell Co. storm is one of the few with hail reported. Hail reports were limited to counties in eastern Oklahoma, outside of out 150 km operations radius.

Figure 1: Radar reflectivity at 18:19 UTC on 16 May 2003.

Figure 2: Differential reflectivity at 18:19 UTC on 16 May 2003.

Figure 3: Specific differential phase at 18:19 UTC on 16 May 2003.

Figure 4: Radar reflectivity at 20:18 UTC on 16 May 2003.

Figure 5: Differential reflectivity at 20:18 UTC on 16 May 2003.