Storms Notes Thunderstorms A storm is a violent

Storms Notes

Thunderstorms • A storm is a violent disturbance in the atmosphere. Storms include thunderstorms, tornadoes, hurricanes, and winter storms. • A thunderstorm is a small storm that often has heavy precipitation and thunder and lightning. • Cumulonimbus clouds form on hot, humid afternoons. They also can form along cold fronts as warm air is shoved upwards.

Thunderstorms • Lightning is a sudden spark in the atmosphere. Lightning can be from cloud to cloud, or cloud to ground. • The superheated air rapidly expands and contracts, starting a wave of sound. • Remember that light travels much faster than sound.

Thunderstorms • • The safest place to be during a thunderstorm is indoors. Be mindful of flash floods. Metal objects can conduct electricity. Water can also conduct electricity (not the water per se, but the stuff in the water). Stay away from objects that can conduct electricity during a thunderstorm.

Tornadoes • • A tornado is a rapidly spinning cloud that reaches down to Earth’s surface. Tornadoes usually form in the wall cloud of a cumulonimbus formation. A tornado can be anywhere from one mile wide, to thin and ropy. Tornadoes typically form at the collision of the Canadian c. P air mass and the Gulf m. T air mass. Tornadoes also form more often in the United States than anywhere else on the planet. The majority of them form in the Great Plains’ “Tornado Alley” and the southeastern “Dixie Alley. ”

Red represents 358 tornadoes from the April 25– 28, 2011 tornado outbreak. Largest outbreak in recorded history.

• • Tornadoes A “tornado watch” is an announcement that tornadoes are possible in your area. A “tornado warning” is an announcement that a tornado has been sighted or indicated by weather radar. If a tornado warning is issued for your area and the sky becomes threatening, move to your pre-designated place of safety. If a building does not have a basement, move to the middle of the lowest floor during a tornado.

• • Hurricanes A hurricane is a tropical cyclone. A cyclone has low pressure. A hurricane has winds that are at least 119 kph. Hurricanes form in the Atlantic, Pacific, and Indian oceans. A hurricane draws its energy from the warm, humid air at the ocean’s surface. The center of a hurricane is called the “eye. ” The eye itself if calm, but the strongest winds are found in the “eye wall. ”

Hurricanes • Hurricanes last a week or more. Hurricanes that form in the Atlantic Ocean are pushed by easterly trade winds toward the southeastern United States. • If you are in an area about to be struck by a hurricane and are told to evacuate, you must leave the area immediately. • A storm surge is a dome of water that sweeps across the coast where a hurricane lands.

Hurricanes • To evacuate means to move away from an area. • If you have to stay in a house, move away from the windows. • It is a myth that you should open windows to prevent damage.

• • • Winter Storms Every year, Rochester and Buffalo in upstate New York receive nearly three meters of snow. This is due to their location in relation to the Great Lakes. Lake-effect snows are created when cold, dry air from Canada blows over the Great Lakes, picking up warm, moist air. As soon as the air leaves the lakes, it will rise and condense, then fall as snow <40 km from the lakes.

Winter Storms • Blowing snows from blizzards can limit how much you can see. • The winds in a winter storm can also cool off you body (hypothermia). • Again, the best place to be is indoors (so long as you have an operational heating unit)