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a line pattern at 1500 meters while the DC-I' flew repeated penetrations at 3000 meters which was about cloud top height. Cloud base was nominally 400 meters. The Electra and the C-130 flew two penetrations of the cloud line (across and back again) at a given altitude before changing flight level. The line was oriented in a northwest-southeast direction and was building on the northern side. When viewed from the northern side, the line presented a very definite leading edge. Conditions to the north of the line were clear and suppressed, the winds were fairly light - on the order of 4-5 m/s - and the air north of the line was cooler and more moist than the air behind. In penetrating the line from the northern side, the wind speed on the surface increased substantially as soon as the leading edge of the cloud mass had been crossed. This was evidenced by the sudden appearance of white caps on the sur- face. It appeared to this observer that near the leading edge, the surface wind speed was greater than the wind speed higher in the sub-cloud layer. In fact, the surface wind speed seemed even greater than the wind speed as low as 30 meters. On the back side of the line, the wind speed was higher than ahead of the line. The trailing edge of the line was very ragged and indefinite. Cloud bases were indefinite and it was hazy. From our vantage point in the subcloud layer, there were no visible towering cumulus; the only evidence of a well defined line of convection was on the radar scope. On both passes through the system at the lower level at least three regions of convergence and divergence across the band were observed. Convergence was observed on both sides of the echoes but the convergence maximum was at the northern edge of the echo pattern on both of the 30 m AGL legs. The zone of maximum divergence was in the echo region on both passes. On the first 30 meter leg (13:56Z to 14:11Z), the maximum convergence was on the order of 10-3 S-l. On the second pass the maximum was about half that amount. Note that microphysical data was limited to the PBL and cloud base level in this case. Further information regarding this case is available from Pennell (1975). B. GATE 261 - September 18, 1974 On September 18, 1974 warm cloud processes wlere responsible for precipitation from rel ati vely small showers observed by radar and ai rcraft duri ng GATE. Numerical analyses by Turpeinen and Yau (1981) compare three-dimensional model results with observations. This case was selected because of its excellent radar documentation of warm clouds and the extensive analyses performed on this GATE case. Soundings with a vertical resolution of 5 mb made aboard the Quandra at 0600, 1200, and 1500 GMT on day 261 were obtai ned "from the Atmospheri c Envi ronment Service of Canada. The environment varied only slightly from 0600 to 1500 GMT and can be adequately described by the 1200 GMT sounding. The temperature profile shows a freezing level at 4.5 km. The dew-point profile indicates that the atmosphere was relatively humid except for two dry layers between 750 and 700 mb (2.6 and 3.2 km) and above 430 mb (>7.1 km). The dry 10. 1"