In general, tornadoes in the Northern Hemisphere rotate counterclockwise (cyclonically) while those in the Southern Hemisphere rotate clockwise (anticyclonically). Occasionally, anticyclonic tornadoes have been observed in the Northern Hemisphere. Typically, anticyclonic tornadoes in the Northern Hemisphere are weaker twisters associated with weak storm cells or sometimes appearing as waterspouts. In 1998, a tornado spinning anticyclonically was observed near Sunnyvale, California. Rarer, but still possible, is a supercell, which generates both cyclonic and anticyclonic tornadoes.