STORMS &

PRECIPITATION

S6E4

Types of Storms:

• Thunderstorm

• Tornado

• Snowstorm

• Hurricane

Watch a Brainpop on Thunderstorms!

• http://www.brainpop.com/science/weather/thunderstorms/

ThunderstormWhat is it?

Small storm with heavy precipitation, frequent thunder & lightning

ThunderstormHow does it form?

• When warm air is forced upward along a cold front & warm, humid air rises rapidly

• In Cumulonimbus clouds (dark, anvil-shaped)

• During Spring/Summer

Go to the Online Textbook…

• Watch Active Art…Ch 12…weather fronts

• http://www.phschool.com/atschool/phsciexp/active_art/weather_fronts/index.html

Thunderstorm rolling in over the city

During a thunderstorm, which comes 1st

lightning or thunder?

LIGHTNING

MCQUEENIS #1!

Thunder always follows LIGHTNING…

Watch a Brainpop on Tornadoes!

• http://www.brainpop.com/science/weather/tornadoes/

TornadoWhat is it?

• Rapidly whirling, funnel-shaped cloud, reaching from the storm cloud to the ground

• Brief, but deadly!

TornadoHow does it form?

• In cumulonimbus clouds with winds at different heights

• In summer/spring

Tornado Alley• as warm, moist

air from the Gulf of Mexico meets cold, dry air from Canada

• 800 or more tornadoes yearly in this area

Watch a Brainpop on Snowstorms!

• http://www.brainpop.com/science/weather/snowflakes/

SnowstormWhat is it?

• Heavy snowfalls that block roads

• Trap people in their cars/homes

• Blowing wind make people lose their way

Blinding snow can disorient people

SnowstormHow does it form?

• Extreme cold

• Air colder than 32°F ALL the way to the ground

Watch a Brainpop on Hurricanes!

• http://www.brainpop.com/science/weather/hurricanes/

HurricaneWhat is it?

• A tropical cyclone

• Winds 119 km/hr or higher

• May be 600 km wide

Hurricane• Forms in the Atlantic,

Pacific & Indian Oceans

• Called a Typhoon in the western Pacific

• Hurricane Season in U.S. from July - Nov

• Eye (center) is calm

HurricaneHow does it form?

• Begins over warm ocean water as a tropical depression tropical storm hurricane

• Last ≥ 1 week

• Loses strength as it crosses land – no water = no hurricane

Storms bring precipitation…

5 Types of Precipitation

• Rain • Hail• Snow• Sleet• Freezing Rain

Depend on the temps!

Rain

• Drizzle

• Mist

• Large drops

• Falls when the temps are above freezing (32°F)

Hail

• Round pellets tossed around in cumulonimbus clouds like a rock tumbler

• During thunderstorms

• Forms at any temp

Snow

• Powdery snow falls through cold, dry air• Clumps together as it falls through humid (wet)

air • Temps below freezing

• Water vapor in clouds made directly into ice crystals SNOW!

Sleet

• Raindrops that fall through air that is below freezing point of water (32°F)

Freezing Rain

• Happens a lot in GA in the winter!

• Raindrops fall through cold air, then freeze as they hit frozen surfaces