STORMS

STORMS

Thunderstorms

• Caused by warm air being forced upward by a cold front into large dark cumulus clouds.

• Produce rain, hail , lightning and thunder.

Lightning• In thunderhead air moves up and down,

causing electrical charges to build. Currents pass between positive and negative charges. The heated air caused by lightning produces thunder. WE see lightning 1st because light travels faster than sound.

Video 1 video 2

Tornadoes

• A small but powerful wind storm with a whirling, funnel-shaped cloud.

• Sometimes form when warm air rushes up to meet cool air.

• Form in open areas, have low air pressure and can rotate over 100 mph.

http://www.youtube.com/watch?v=2GWtfb5l8iA

Hurricanes

• Large tropical storm that covers thousands of sq kilometers.

• Winds spiral toward center of storm with speeds up to 320 km per hr.

• Center, eye, is calm. • All hurricanes form over ocean near equator.

Start out as tropical storms and grow stronger over warmer water.

• Cause flooding, excessive rain, and huge winds.

http://www.youtube.com/watch?v=Cdh853PdVb0