CUMULONIMBUS CLOUDS REACHING HIGH THE ATMOSPHERE DEVELOPED FAIR WEATHER CUMULUS EXIST TOWERS SQUALL LINE CONVECTIVE IN EXCESS TOPS REACH FEET PHOTOGRAPH NOAA CONSIST WATER DROPLETS HIGHER TEMPERATURES BELOW DEGREES CELSIUS ICE CRYSTALS ATMOSPHERIC CONDITIONS CLOUDS QUICKLY DEVELOP POWERFUL SUPERCELLS DEEP ROTATING LIFETIME PRODUCE HOLLE STORMS AFTERNOON EVENING HEATING THE SUN INFORMATION WEATHER VISIT SEVERE STORM FAIR CUMULUS TERMS DATA CREDITS DEPARTMENT OF ATMOSPHERIC SCIENCES UNIVERSITY OF ILLINOIS AT CLOUD