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Cloud development within the analysis domain clearly indicated preferential thermodynamic and kinematic regions. These were described in observational stu- dies by Auer and White (1983). A successful mission was flown on three vigorous cumulus congestus that were located approximately 50 km west of the CP-2 radar and outside of the CCOPE sur- face mesonetworks. The first two targets were on the upwind portion of a cloud line oriented south- west to northeast while the third cloud was isolated. Warm cloud-base tem- peratures (TLCL = 7 OC) and above average moisture content (q = 7.9 g kg-I) combined to produce lower than average cloud bases (RiLCL = 2140 m). All three clouds were multi-turreted with tops estimated to be near 6000 m MSL. Vertical velocities in excess of 5 m s-1 were recorded during the penetration legs but cloud base updrafts were weaker. Aircraft soundings were completed near the target clouds. Later in the day the radars studied two mature storms that passed from west to east over the Doppler network. These storms moved at 30 to 40 km with inflow on the south and southeast sides. Echo top heights were ~10 km MSL and maximum reflectivity was >55 dBZ. Excellent radar data is available. The second storm produced hail northeast of Miles City. C. CCOPE - August 1, 1981 August 1, 1981 was selected for sensitivity studies of more intense convective environments. This case had 3 to 4 hours of continuous Doppler radar data which permits excellent analyses of particle motion and precipitation evolution. A number of scientists are studying this case with specific emphasis on water budgets and precipitation evolution. The storms which formed on the afternoon of August 1, 1981 in eastern Montana developed under relatively weak synoptic conditions. The flow aloft over the region was out of the west to west-southwest wi~h m~derate shear below 6 km (=5x10-3 s-l) and weak shear above 6 km (<3x10- s-). No short wave troughs are evident in the upper air maps although a quasi-stationary trough was located on the west coast of the U.S. A major wave had passed over the area 36-48 hours earlier (on July 30) and had brought much drier air to eastern Montana. Mixing ratios in this airmass dropped to 5 g kg-1 in the CCOPE surface network. As the anti-cyclone passed across the region the low level winds gradually became southeasterly again and the humidity returned rapidly to eastern Montana. During the 24-hr period precedin~ storm development, low level mixing ratios increased from 7 to nearly 13 g kg- in some areas. At 700 mb a strong thermal gradient was located over the region with cooler temperatures northeast and warmer south- west. The effect of this thermal pattern was to "cap" convection over the west and south. Research aircraft departing Miles City in the early afternoon recorded a decrease in 700 mb temp from 12.8 oc over Miles City to about 10 oc in the vicinity of the developing storms. It appears that the storms may have formed near the location where the low level moist air emerged from beneath the warm 700 mb inversion. Satellite pictures from GOES-West show a field of cumu- lus and towering cumulus over the CCOPE network showing many potential 20.