Colour Plate 1 Cross-sections through a tornado-producing supercell storm showing wind fields and precipitation activity at four different height levels: (a) 0.5 km, (b) 3.5 km, (c) 7.5 km and (d) 13.5 km. The wind pattern is shown by arrows according to the scale shown at the bottom right of each frame, and the precipitation is indicated by its radar reflectivity in dBZ, colour-contoured as per the ribbon scale on the right. Both reflectivity and winds are sensed by a 3 cm airborne Doppler radar flying at an altitude of 5 km. A fore/aft scanning technique (FAST) (see Section 6.6.5) is used

Colour Plate 1 cont. for data collection, and vector winds are synthesised using pseudo-dual-Doppler processing (see Section 6.6.5). The pronounced rotational motion of the air within the storm is apparent in the three lower levels (a,b,c), and the strong storm-top divergence is clearly marked at the highest level ( d). (Reference: Dowel, D.C., Bluestein, H.B. and Jorgensen, D.P.: Airborne Doppler radar analysis of supercells during COPS-91 , Month. Weather Rev., 1997, 125, pp. 365 383. Courtesy D.C. Dowell, University of Oklahoma)

Colour Plate 2 Radial velocity field of an undular bore phenomenon in central Oklahoma, observed with a 10 cm Doppler radar. The elevation angle is 2.3 and the range circles are in kilometres. As many as eight cycles of undulation are visible. (Courtesy R.J. Doviak, NOAA National Severe Storms Laboratory, Norman, Oklahoma)

Colour Plate 3 Composite reflectivity map from a WSR-88D radar,...