STORMSSTORMS

Weather jokes?Weather jokes?

Shoulder PartnerShoulder Partner

Describe to your partner the scariest storm you’ve ever been in and what took place.

Close Encounter!Close Encounter!

Types of storms…Types of storms… Storms – a violent disturbance in the atmosphere. Rain/Snow storms – formed when two different fronts

collide (warm meets cold)Summer = steady rainWinter = heavy snowfallBlizzard = wind must reach 36 km/hr and

be -7 degrees Celsius.Ice storm = rain freezes instantly.

* Thunderstorms – cold meets warm front forming heavy rainstorms with thunder and lightning, has violent down drafts and strong wind shear.

Face PartnerFace Partner

Which type of storm do you believe is the most deadly, meaning that is takes the most lives?

Ice Storms…Ice Storms…

LightningLightning

Lightning – sudden discharge of static electricity (cloud to cloud; cloud to ground)

Leading cause of forest fires. Can strike people, animals, or buildings.

When the air is heated by lightning it expands quickly resulting in loud sound waves (thunder).

Safety – avoid open spaces outside; don’t go under trees for shelter, and avoid sinks, bathtubs, televisions, and telephones while inside during a lightning storm.

If you hear thunder 3 seconds after a flash of lightning; the storm is only 1 km away.

Lightning continued…Lightning continued…

Table Talk…Table Talk…

What is a cyclone?

Cyclones and Anticyclones?Cyclones and Anticyclones?Cyclones – any area of low pressure

containing rising warm air. Causes rainy stormy weather.

Anticyclones – any high pressure area. Causes dry, fair weather.

Now for a laugh!Now for a laugh!

HurricanesHurricanesHurricanes – power cyclones that

forms over tropical areas.Typhoon – hurricane that forms

over the W. Pacific ocean.The rapidly, spinning rising air

forms a donut-shaped wall of strong winds, clouds, and rainfall. The eye of the storm is always calm. (speeds of 74 to over 155 m/hr)

Considered the most powerful of all storms.

Hurricanes and TyphoonsHurricanes and Typhoons

Map of a hurricane…Map of a hurricane…

How are hurricanes How are hurricanes categorized?categorized?

The Saffir-Simpson Scale

Storm ChasingStorm Chasing

Shoulder Partner…Shoulder Partner…

Would you ever go on a storm chase? Why or why not?

TornadoesTornadoes

Tornadoes – incredibly destructive; a whirling, funnel-shaped cloud of low pressure. Develops in heavy cumulonimbus clouds. Acts like a giant vacuum cleaner, due to the low pressure. Not sure how they form, usually in the spring in late afternoons or evenings. Most common in the United States.

Map of aMap of a tornado… tornado…

Tornadoes continued…Tornadoes continued…

More about tornadoes…More about tornadoes…

Great Plains is “tornado alley”.Average diameter of a tornado is .4 kmAverage length traveled – 6 km for

only a few minutes.Winds can still reach more than 350

km/hour.Measured on the Fujita scale as F0 –

F5. (five being the strongest).

Tornado alley?Tornado alley?

Fujita ScaleFujita Scale

Precipitation typesPrecipitation typesand and

CloudsClouds

Can weather predict disaster?Can weather predict disaster?

Types of clouds…Types of clouds… Cumulus –(cotton balls) are fluffy and white with

flat bottoms. Indicate fair weather. Cumulonimbus – (thunderclouds) when cumulus

clouds grow vertically and darken. Stratus – gray clouds that cover the whole sky and

block out the sun. Light rain and drizzle are usually associated with these clouds.

Cirrus – feathery clouds. Sometimes called “mare’s tails”. Indicate that it will rain/snow in the next 24 hours.

Cumulus Cirrus

Stratus Cumulonimbus

Cumulonimbus sCumulus

StratusCirrus

Odd-shaped cloudsOdd-shaped clouds

Do you see what I see?Do you see what I see?

Even more…Even more…

PrecipitationPrecipitationWhen water vapor in the clouds becomes too heavy, it

can fall as rain, sleet, snow, or hailCloud droplets must first increase in size until gravity

pulls them downWhen droplets pass through extremely cold layers of air

as they fall, they freeze and produce sleetSnow is formed when water vapor (gas) changes

directly into a solid. Process is called deposition.Hail is formed within the cloud.

You are done!You are done!