On a molecular level, the structure of chlorophyll is very similar to heme, which is a part of hemoglobin present in human blood. Heme, which is what makes blood appear bright red once exposed to oxygen, is bound to proteins forming hemoglobin.
Lightning is a bright flash of electricity produced by a thunderstorm. All thunderstorms produce lightning and are very dangerous. If you hear the sound of thunder, then you are in danger from lightning. Lightning kills and injures more people each year than hurricanes or tornadoes; between 75 to 100 people.
The short answer is: thunderstorms. You're already aware that there are severe up- and downdrafts associated with cumulonimbus clouds. It's this air movement that allows hail to form. The warmer water droplets from below are swept above the freezing level by the updrafts.