September 13, 2002: Stratiform with convective line Author: Pam Heinselman, CIMMS/OU Last Updated: 14 April 2003

Forecast/Weather:

On 13 September 2002, a surface low is approaching northwestern Oklahoma at 12 UTC. Ahead of this low, a short line of convective cells develops on the southwestern end of an area of stratiform precipitation, over north-central Oklahoma.

Radar Operations:

Start time: 20:45 9/13/02 UTC (15:45 9/13/02 local time)
Stop time: 21:18 9/13/02 UTC (14:18 9/13/02 local time)

Start time: 23:04 9/13/02 UTC (18:04 9/13/02 local time)
Stop time: 23:54 9/13/02 UTC (18:54 9/13/02 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Cold season
Radar: Calibration appears a bit high since the maximum correlation coefficient is greater than one.

Operational Delivery:

Not applicable.

Snapshots:

Figure 1: The radar reflectivity field shows a convective line along the southwest end of an area of stratiform precipitation at 23:37 UTC 13 September 2002. A fine line in the reflectivity field indicates an outflow boundary ahead of the southern end of the line.	Figure 2: The differential reflectivity field shows oblate raindrops (1.2 - 2.8 dB) along the leading edge of the convective line and embedded in the stratiform precipitation at 23:37 UTC 13 September 2002.
Figure 3: Higher values (0.8-2.0 deg) of specific differential phase along the leading edge of the convective line and embedded within the stratiform precipitation indicate relatively high rain rates at 23:37 UTC 13 September 2002.	Figure 4: The hydrometeor classification algorithm identifies convective precipitation along the leading edge of the convective line and embedded within the stratiform precipitation at 23:37 UTC 13 September 2002.