Phase composition of cumulus clouds in the Camagüey meteorological site

The time evolution of phase composition and other main characteristics of tropical cumulus clouds measured as part of the Cuban Weather Modification Program in the Camagüey Meteorological Site are presented. Measurements were made from an AN-26 instrumented aircraft at a flight level nearly 6 km, with air temperature ranging from -7 to -10 0C. Clouds top heights ranged from 6 to 8 km. Ice concentration obtained for particles greater than 120 microns, was less than 2-3 per liter for young developing cumuli. The ratio of solid to total water for this clouds was less than 0.1- 0.2. Moderate increases of ice content were detected 12 - 15 minutes after first echo in an x - band radar. The analysis of the time evolution of the phase composition allowed finding a seeding window for the development of ice particle of 20 minutes after first echo.