Severe Weather 48 Thunderstorms and tornadoes occur because

Severe Weather

• 48) Thunderstorms and tornadoes occur because of sudden changes in air pressure or as a fast moving cold front hits a slow moving warm front.

• 49) Large thunderstorms and tornadoes occur most frequently in the spring and summer. The ground is warming and warm air masses move north from Mexico, while cold air masses move south from Canada.

50) Tornadoes are a destructive vortex of violently rotating winds having the appearance of a funnel-shaped cloud and advancing beneath a large storm system.

• 51) A severe storm that forms as a rapidly rotating funnel cloud is called a tornado.

• 52) A hurricane is a large tropical storm system with high-powered circular winds.

• 53) Lightning is as hot as the surface of the sun.

• 54) When clouds collide they either lose or gain electrons. This difference in electrons causes an electron imbalance. When the electrons flow together to balance the electron inequality, lightning occurs.

• 55) Hail is formed by a rising current of warm air forces water drops to rise. When the water droplets reach colder, higher altitude they freeze. The frozen rain droplets fall to the ground as hail.

• 56) Hurricanes are the largest of storm systems.

• 57) The storm surge of a hurricane causes the most deaths during the storm.

• 58) Tornadoes have the highest wind speed of all storms systems.

• 59) Events, such as volcanic eruptions and clear cutting of trees in the rainforest, can have global effects on weather patterns.