October 27, 2002: Stratiform Precipitation and AP/BS Author: Pam Heinselman, CIMMS/OU Last Updated: 7 April 2003

Forecast/Weather:

A large area of AP with biological scatterers existed around KOUN during the night; it abated by early morning (2-9 UTC). Stratiform precipitation was observed over northwest Oklahoma beginning in the early evening. This area of precipitation moved across central Oklahoma during the night and morning of 27 October (UTC).

Radar Operations:

Start time: 02:02 10/27/02 UTC (20:02 10/26/02 local time)
Stop time: 21:23 10/27/02 UTC (15:23 10/27/02 local time)

Radar/Operational Status:

Hydrometeor Classification Algorithm: Warm season

Operational Delivery:

Not applicable.

Snapshots:

/table>

Figure 1: Large bloom of reflectivity around KOUN indicates anomalous propagation (2:44 UTC).	Figure 2: High differential reflectivities within radar reflectivity bloom (see Fig. 1) indicates the presence of biological scatterers.
Figure 3: Low correlation coefficients, colocated with high ZDR and low reflectivities, indicates biological scatterers.	Figure 4: The hydrometeor classification algorithm identifies both biological scatterers and precipitation (area of lower ZDRs northwest of KOUN) around KOUN. Interestingly, the area with high ZDRs northeast of KOUN is not classified as BS.
Figure 5: Radar reflectivity shows stratiform precipitation over central Oklahoma (15:10 UTC).	Figure 6: The hydrometeor classification algorithm identifies moderate rain within the northern part of the system, and light rain elsewhere.