.....ice in clouds is the key to really big electrical storms. Ice
creates lightning and often heavy rain.

Ice is vital to the development of lightning. Different-sized ice
particles within a cloud carry a positive or negative charge. As the
particles collide, that charge builds up. When the charge is released
-- we see lightning.

Satellites watch lightning flashes from space, helping scientists to
learn more about them.

"We know how much ice is associated with a given number of lightning
flashes, ...we can say something about the amount of rain that falls
out of those clouds."

....satellite observations indicate that in order for lightning to
form, thunderstorm clouds need to have a high content of ice.

Walter Petersen, a meteorologist at the University of Alabama,
Huntsville, analyzed observations of lightning and precipitation from
1998 to 2000 taken from the Tropical Rainfall Measuring Mission
(TRIMM), launched in 1997.

The relationship between the number of lightning strikes and how many
ice crystals are present in clouds is the same regardless of different
atmospheric environments over oceans, coasts, and continents. The
relationship between rain and lightning, in comparison, does not show
this same level of consistency.

Storm clouds form as moisture evaporates from the earth into the
atmosphere, where the droplets jostle against each other. The air
cools off rapidly with as it reaches higher altitude. Sometimes a cold
front - the boundary between where the cold air from one thunderstorm
meets the air outside the storm for example - will force the moist air
upward into the colder air. This moist air cools off and the water
vapor "condenses" into liquid drops, forming clouds. The process
continues: more and more water vapor turns into liquid, and the moist
air warms up even more and rises higher and higher. A thunderstorm
results.

[More exactly a thundercloud results.]

As more and more water droplets collide inside a cloud, their atoms
bounce off each other more forcefully. This knocks off electrons.

The ousted electrons gather [Wrong. Not rewriting electron theory -
when it becomes electron fact; that might be a subject for discussion
but: The idea that an electric charge can build up in the atmosphere
has been overturned by fairly recent research. This part of the
article is sloppy journalism.] at the lower portion of the cloud,
giving it a negative charge, while the upper part of the cloud becomes
positively charged.

Eventually the growing negative charge becomes so intense that
electrons on the Earth's surface are repelled and burrow deeper into
the Earth. The Earth's surface becomes positively charged, and hence
very attractive to the negative charge accumulating in the bottom of
the cloud. All that is needed is a conductive path between cloud and
Earth, in the form of ionized air. [Huphpffppph!]

The American Meteorological Society contributed to the information
contained in the TV portion of this report:
http://www.sciencedaily.com/videos/2006-10-11/