Severe Weather

Thunderstorms * a small intense weather system * formed along cold fronts * warm moist unstable air near the earth’s surface rises (convection) * form cumulonimbus clouds * clouds can reach 40,000 feet tall!

Severe Thunderstorms

Doppler Radar

Lightning

Lightning * an electric discharge that occurs between positive and negative charges * lightning can happen between clouds or clouds and the earth * lightning causes the air to expand and contract rapidly to create thunder * lightning can be 33,000*C that’s hot! *lightning kills more people than other storms …Florida and Africa have the most strikes!

Hurricanes

Hurricanes * Tropical weather system Low pressure * winds at least 120 km/hr * form over warm ocean water * called typhoon in the Pacific ocean * called Hurricane in the Atlantic Ocean * called Cyclone in the Indian Ocean * formed by thunderstorms over warm tropical waters …winds traveling in different directions meet and cause spin

Tracking Hurricanes

Parts of a hunrricane

Tornadoes

Tornadoes * happen in only 1% of thunderstroms * a small spinning cloud with high speed winds that are a low pressure * forms from a funnel cloud poking out the bottom of a cumulonimbus cloud along a cold front where it collides with warm moist air * 75% of the worlds tornadoes occur in the United States

Tornado Alley

Waterspouts

Weather Station Symbols