1. SEVERE WEATHER - STORMS

2. What is a storm? A storm is a violent disturbance in the atmosphere.
Storms involve sudden changes in air pressure, which can cause rapid air movement.

3. TORNADOES
(1)
Are rapidly whirling funnel- shaped clouds that reach down from a storm cloud to touch Earth’s.
Form from the same clouds that bring thunderstorms.
Wind speeds can reach 500 km/h (300 mph)
These are NOT predictable.

4. TORNADOES (continued)
Most are about 250 feet wide and last 15 minutes or less.

5. THUNDERSTORMS These are the MOST COMMON form of severe weather.
(2)
These are the MOST COMMON form of severe weather.
Form inside warm moist air masses and at warm fronts.
Warm air is rapidly pushed up and form huge clouds.
As the warm air rises, it cools and forms dense thunderheads.

6. THUNDERSTORMS (continued)
Heavy rain falls, sometimes with hail.
The falling rain drops cause strong winds.

7. HURRICANES
(3)
Are large (can cover several states), swirling low pressure systems that form over tropical oceans.
They get their energy from the warm waters.
They start out as tropical storms that grow in size and strength.

8. HURRICANES (continued)
When wind speeds hit 120 km/h (75 mph) the tropical storm is called a hurricane.
Cooler air sinks over the land.
When hurricanes reach land, they gradually lose strength and slow down.

9. HURRICANES (yet again!!!)
Hurricanes are so large they can be seen from space.