Severe Weather

Severe Weather

Name: ______Period: ______

Severe Weather


  • Thunderstorms are small, intense weather ______.
  • Strong winds
  • Heavy ______
  • Lightning and thunder
  • Occur along ______fronts

In order for thunderstorms to occur:

  • The air near the Earth’s surface must be ______and moist.
  • The atmosphere must be unstable.
  • The air surrounding the rising warm air mass is ______.
  • This causes the warm air to rise rapidly.

Lightning and thunder

  • Lightning is a large electrical discharge between two ______charged surfaces.
  • Thunder is the sound that results from the rapid ______of air along the lightning strike.

How lightning forms diagram:FILL IN THE BLANKS BELOW

Thunderstorm Formation Video:

Thunderstorms are essentially caused by ______in

______and ______.

The electrical disturbances in the atmosphere are caused by the rapid

______of ______.


  • A tornado is a small, rotating ______of air.
  • Forms during thunderstorms.
  • High wind speeds
  • Center of a tornado is called a ______.
  • 75 % of a all tornadoes occur in the U.S.
  • U.S. averages about ______per year.

Tornado Formation:

  • Wind travels in two different directions.
  • Air between begins to ______.
  • The “roll” turns vertically and begins to rotate because of the ______.
  • Turns into a funnel and touches the ground.

Tornado Formation Diagram:

Tornado Video:

How long can tornadoes last? ______

List 2 things you should do if there is a tornado nearby:

  1. ______
  1. ______


  • Waterspouts are tornadoes that form over ______.
  • Tornado Alley – an area east of the ______Mountains. It is mainly in Texas, Oklahoma, and Kansas that experiences the highest number of tornadoes per year.
  • Why? Cool dry air (north) meets warm moist air (______).

Tornado Alley Diagram:LABEL THE STATES

tornadyalley climatology

Fujita Scale:

F-0 40-72 mph, ______damage, tree branches broken

F-1 73-112 mph, mobile homes pushed off foundation or overturned

F-2 113-157 mph, considerable damage, mobile homes demolished, trees ______

F-3 158-205 mph, roofs and walls torn down, trains overturned, cars thrown

F-4 207-260 mph, well-constructed ______leveled

F-5 261-318 mph, homes lifted off foundation and carried considerable distances, ______thrown as far as 100 meters


The Fujita Scale in detail

Hurricanes Study Guide

Ingredients for a Hurricane to form:

1. Ocean water temperature ______°or more.

2. Surface level low pressure

3. Upper level high pressure.

So what would cause a hurricane to weaken?

  1. If the hurricane moves into ______water.
  1. If the hurricane moves over ______.

Hurricane Development

1. Tropical Wave: a large, ______area of rain.

  • This usually forms off the coast of Africa.
  • No symbol.

2. Tropical ______: a storm spinning counterclockwise with winds <39 mph.

Symbol is:L

3. Tropical Storm: a storm spinning clockwise with ______between 39 and 73 mph.


4. Hurricane: a storm ______counter clockwise with winds > 74 mph.


Parts of a Hurricane – label the parts in the blanks

hurricane structure

Eye – the ______, low pressure center of a hurricane.

  • 5-30 miles wide.

Eye wall – the dense wall of ______surrounding the eye.

  • The strongest and most intense part of a hurricane.

Rain bands – the spiral bands of ______surrounding the eye wall.

  • The largest part of a hurricane


Storm surge – large surge of water near the coast.

  • This causes the most ______!

Hurricane season is from ______to ______.

Saffir Simpson Scale

The ______to measure hurricanes is called the Saffir Simpson Scale.

Category 1 is the weakest.

Category 5 is the strongest: winds > 157 mph.

2014 Hurricane Names:

Hurricane Katrina - ______

She was a Category 5 at one point, but she made landfall in U.S. as a category 4.

Hurricane Katrina Formation Video

  1. How warm was the ocean water when Hurricane Katrina formed? ______
  1. What category storm was Katrina when she glanced off of Florida? ______
  1. What made Katrina grow stronger when she went into the Gulf Of Mexico? ______


Only 3 Category 5 hurricanes have ever made landfall in the United States:

  • 1935 ______Hurricane
  • 1969 Hurricane Camille
  • ______Hurricane Andrew