1. Introduction

Military chaff is observed by the NWS WSR-88D routinely. Data from 14 April 1997 show still another example of the effects of chaff on the WSR-88D algorithms. Please see Vasiloff's technical attachment No. 97-02 for a more indepth discussion of effects of chaff.

2. Data

Figure 1 shows the composite reflectivity, 4-panel of the lowest 4 radar sweeps, and the cell table from NSSL's radar display program. Two cells are indicated in the cell table. The entire area of reflectivity, however, is from chaff. The 4-panel indicates that nearly all of the echoes at at the lowest tilt. The proof that the echoes are from chaff is in Figure 2 that shows visible satellite imagery within minutes of the WSR-88D data. Please note that there are no clouds in the area to the southwest of the Great Salt Lake.

FIGURE 1. Doppler radar images at 1756 UTC from NSSL's radar algorithm and
display system.

FIGURE 2. Visible satellite imagery on 14 April 1997 at 1800 UTC.