Do you know the difference between a hurricane and a typhoon? Find definitions for weather terms from absolute humidity to zonal flow and everything in between in the WeatherBug weather glossary.

Lifted Index (or LI)

A common measure of atmospheric instability. The value is obtained by computing the temperature that air near the ground would have if it were lifted to some higher level (around 18,000 feet/5,486 meters, usually) and comparing that temperature to the actual temperature at that level. Negative values indicate instability - the more negative, the more unstable the air.

More Glossary Terms:

• Isotherm
• Jet Stream
• Lapse Rate
• Latitude
• Leeward

• Lightning
• Local Winds
• Low
• Mean
• Meteorologist