Winds Local Winds Blow over small areas depend

Winds Ø Local Winds – Blow over small areas – depend on local weather conditions. l Can blow in any direction. These are the winds you feel each day Ø Special local winds l l l Land – Sea Breeze Mountain – Valley Breeze Monsoon

Winds Ø Planetary Winds – Blow over huge areas l Always blow in the same direction

Planetary Wind Belts Ø Tradewinds – Gentle steady winds that blow from east to west from 300 toward the equator. Ø Prevailing Westerlies – Blow from southwest toward northeast between 30 and 600. Belt we live in. Ø Polar easterlies – Dense cold air that blows east to west from the pole toward 600

Jetstream Ø Band of fast moving air blows from west to east – separates cold and warm air in north america

Planetary Wind belts

Storms Ø A disturbance in the earth’s atmosphere Ø Nature’s way of reaching an equilibrium l Storms equalize all weather variables

Thunderstorm Ø Associated with high temperatures over land areas Ø Thunderstorm cells (30 - 60 minutes) l l l Hot moist air rises causing fast updrafts Condensation releases heat more air rises Cumulus clouds form Heavy rain causes downdraft and cools ground Storm ends

Thunderstorms Ø Squal lines – Line of thunderstorms ahead of a front Ø Supercell – Very large thunderstorm. Start of a tornado

Thunderstorm

Lightning Ø Discharge of electricity between thundercloud and ground or other cloud l Static electricity Ø Thunder – Sound made when air rapidly expands as electric charge passes through it. Electric charge heats the air and causes shockwave.

Lightning

Tornado Ø Violent rotating column of air associated with a thunderstorm l l l Low pressure center called the vortex Sucks in air and the air rises Top wind speeds of 250 mph

Tornado

Hurricane Ø Large rotating tropical storm that has sustained winds of over 75 mph. l l l Huge storm up to 500 miles across Low pressure center Top winds of over 150 mph

Hurricane

Blizzard Ø Winter storm with the following conditions l l l Wind must exceed 33 mph Temps of 190 or lower Blowing and drifting snow reduce visibility

Blizzard