13.1 notes Thunderstorms

• Extreme weather is controlled by the same processes as good weather.

Main idea

• Moisture in low-mid levels of atmosphere

• A lifting force to cause air to begin rising; such as heated air near the ground!

• Unstable air (air that will continue rising & rising!!)

Atmospheric conditions required

Thunderstorms

• LightingDevelopment: a buildup of charges forms as tops of clouds become +++ charged & bottoms of clouds become ---- charged.

Components of thunderstorm

• Thunder Development: Lighting quickly heats the air around it, causesrapid expansion & a “boom” sound.

Describe:A violently rotating column of air rising up into a cloud & also touchingthe ground below.

Tornadoes

Extreme weather produced by thunderstorms

Tornadoes Conditions required:• Wind Shear: a change in speed &

direction at differ altitudes: causes clouds to spin.

• Sinking air pushes one end of column towards land. Other end rises: spins faster!!

• Spinning cloud joins & creates a funnel cloud.

• When funnel cloud touches ground, it creates a tornado!!!!!!!!!!!!

Describe: low-pressure weather systems w/ circular wind motion; rotates counter-clockwise in N. Hemisphere.

Tropical Cyclones

“Eye am watching you!”

Explain names:

TYPHOON: when thunderstorms converge in the W. Pacific or Coast off of China.

Philippines

HURRICANE: when storms are born off of the coast of Africa & travel across the Atlantic Ocean.

Conditions Required: • Growth is over warm ocean waters !

• Air spins & rises, then it cools & causes it to release heat

• When wind reaches 74+mph: called a hurricane!!

Describe: Winter storms that bring lower temps, high winds, heavy snow, & poor visibility.(Alaska! Need I say more!)

Other extreme weather: blizzards

“You are a crazy old man”