Severe Weather --for those who know enough to come in out of the rain.

Flash flooding

Tornado

High winds

Lightning

Thunderstorm

Hurricane

Winter storms

Over 500 Americans die each year due to weather related incidents. Billions of dollars of damage is done to American homes, farms, cities, and businesses

Rule 1 Warm air tends to…

Rule 1 Warm air tends to rise! Just like warm water and warm magma Convective uplift—it is forced up by the cooler (and therefore more dense) fluid around it.

Four reasons air might rise:

Four reasons air might rise: 1. Convective uplift 2. Orographic uplift 3. Frontal wedging 4. Convergence

Four reasons air might rise: 1. Convective uplift --less dense air is forced up by surrounding air 2. Orographic uplift --if the land surface rises, the air has to rise 3. Frontal wedging --an air mass forces its way under another mass 4. Convergence --when two air masses come together, the only way to go is up

Air Masses --like water masses. A body of air with its own temperature and humidity

Air Masses --like water masses. A body of air with its own temperature and humidity Continental (dry) or Maritime (humid) Polar (cold) or Tropical (warm)

Front-where two air masses meet Cold air mass (moving southeast) Warm air mass Cold air mass Warm air mass (moving east)

Fronts

When a front advances…

…one air mass goes over the other. The warmer air mass usually goes over the other.

Clouds form…

…when an air mass cools enough to allow the water vapor to condense. When a warm air mass rises, it starts to cool due to expansion—air pressure is less up there Cold Air mass 

Clouds form… …or they don’t. Water vapor is clear and colorless-- Air has water vapor. Clouds have water droplets.

Clouds form… …or they don’t. Water vapor is clear and colorless-- Air has water vapor. Clouds have water droplets. Condensation nuclei make it more likely that water vapor can condense into water droplets

Cumulus clouds make thunderstorms

Cumulonimbus clouds (raining)

Air movement in a thunderstorm

Types of clouds Basically—three types are important: Stratus Cumulus and Cirrus

Types of clouds Basically—three types are important: Stratus Cumulus and Cirrus means “a layer” means “heaped” means “wispy”

Types of clouds Basically—three types are important: Stratus Cumulus and Cirrus Nimbus = “raining” Alto = “high” Combination types take both names

Types of clouds

Cirrus clouds

Stratus clouds

Cumulus clouds

Cumulonimbus

Complete numbskull

Above the clouds

Weather occurs in the troposphere

Above the clouds Air cools as you get higher

Above the clouds Top of Mt. Everest

Above the clouds The tropopause is the top of the troposphere

Above the clouds Highest clouds

Above the clouds Passenger jets fly here

Above the clouds Propeller plane altitude record

Above the clouds Jet plane altitude record

Above the clouds Air doesn’t get cooler with altitude in the stratosphere

Above the clouds Ozone layer

Above the clouds Cooling with altitude, again

Above the clouds NASA gives astronaut’s wings above the mesopause

Above the clouds Northern lights