1. 5.3 (A)
Severe Weather
Pages
4.3 Severe Weather
Pages

2. Youtube videos Severe Storms NOVA PBS 3:38
Lightning 101 National Geographic 2:38
Mr. Parr Thunderstorms
Hurricanes 101 National Geographic 3:30
Mr. Parr Hurricanes and Twisters
Tornados 101 NG 2:46
STORM CHASERS: Inside a tornado NG 4:15
Tornado Safety Tips by Martin Peters 4:54
Oklahoma Tornado 2013 (Strongest tornado ever recorded )

3. can cause major damage, injuries, and death
Severe Weather
can cause major damage, injuries, and death
thunderstorms, hurricanes, blizzards, and tornados

4. Severe Thunderstorms
Dangerous storms that contain damaging winds, heavy rain, hail, thunder, and lightning

5. Weather conditions needed:
- low pressure system
- warm temperatures
- moisture
- an energy source of updrafts (air
moving vertically up) and downdrafts
(air moving vertically down)

6. Stages of a Thunderstorm
1. Cumulus Stage
warm air rises and forms tall cumulus clouds
the rising air creates updrafts
the air condenses and forms precipitation

7. 2. Mature Stage
The cold upper air is dense and sinks causing downdrafts.
The constant motion of up and downdrafts produces strong winds, heavy rain, lightning and thunder.

8. 3. Dissipating Stage
storm loses energy
downdrafts continue, but updrafts slow and finally stop
Rain and winds fade

10. Lightning electricity found in all thunderstorms
strong updrafts/downdrafts cause millions of ice crystals to rise/sink.
they bump into each other creating electrically charged particles

11. lightning can move within the same cloud
between clouds and from cloud to ground

12. most people struck are not killed, but suffer major injuries and burns.
they do not continue to carry an electrical charge after being struck
kills or seriously injures 75 to 100 people yearly
Florida has the most lightning strikes in the US

13. Thunder the sound heard after lightning
as lightning travels through the air, it super-
heats the air to a temperature of 27,000°C
the air expands because of the intense heat
once the lightning passes, air contracts and
creates a sound wave

14. we see the flash of lightning before we hear thunder because light travels faster than sound.
Lightning can be seen 100 miles away.
Thunder can be heard up to 15 miles.

15. To estimate the distance of a storm:
1. begin counting when you see lightning
2. stop counting when you hear thunder
thunder travels one mile in 5 seconds, therefore the storm is 1 mile away for every 5 seconds counted

16. Severe Weather Watch vs Warning
a watch means severe weather is possible
a warning means severe weather is already occurring

17. Thunderstorm Safety Tips
go to a safe place immediately (sturdy building or car)
Avoid metal objects and water (both good conductors of electricity)

18. Avoid tall objects, lightning usually strikes the highest point
do not use electrical equipment
wait at least 30 minutes before going back outside

19. Hurricanes
Intense tropical storms that form between 15° North and South latitude from the equator
winds spin counterclockwise in excess of 119 km/h or 72mph
average size is 30 miles across which is 150 times larger than a tornado

20. most destructive storms because of strong winds and heavy rain that cause flooding.
a storm surge occurs when ocean water floods coastal areas

21. Formation of a Hurricane
hurricanes start as thunderstorms off the southwest coast of Africa.
warm ocean water, above80°F provides the energy for the storm and causes more evaporation.

22. humid air rises, condenses, forms clouds
As more air rises, it creates an area of low pressure over the ocean.

23. winds above 22mph – Tropical Depression
winds above 38mph- Tropical Storm
winds above 72mph – Hurricane

24. Storms begins to dissipate as they move over land or cooler water because they lose their energy source
only about 1% of tropical storms become hurricanes.

25. Hurricane Structure
The eye is the center of the hurricane and the calmest part of the storm.
The eye wall surrounds the eye and has the most damaging winds and heaviest rain.
Rain bands are thunderstorms
that extend from the eyewall
and spiral counterclockwise

26. Atlantic Hurricane Season
June 1 to November 30
most hurricanes occur  in late summer
(August-September)

27. The National Weather Service
provides updated information and issues watches and warnings
data comes from satellite images or is
supplied by airplanes flying directly into and around hurricanes

28. hurricanes are given categories based on the strength of winds and amount of damage caused

30. Hurricane Watches and Warnings
a hurricane watch means there is the possibility of hurricane conditions within 36 hours
A hurricane warning means hurricane conditions are expected within 24 hours and preparation should start

31. Hurricane Safety
keep an emergency kit with supplies ready
take measures to protect your property and plan an evacuation route for your family

32. The World Meteorological Organization
in 1953 the WMO began naming tropical storms and hurricanes
until 1979, only female names were used
The letters Q, U, X, Y, and Z are never used

33. a name is retired from the list when a hurricane has caused death and destruction

34. Tornados
Violent whirling columns of air extending from thunderstorms that come in contact with the ground
Occur mostly in spring and summer with little or no notice can be given

35. the diameter can be several miles wide and reach speeds of over 260mph
Moves on the ground in an unpredictable path which makes it hard to predict and can destroy entire buildings and cause thousands of injuries or deaths. 

36. Formation of a Tornado
cool dry air from Canada comes in contact with warm humid air from the Gulf of Mexico.
updrafts begin rotating counterclockwise and
the unstable air creates large thunderstorms

37. swirling winds begin to spiral downward from the base of the T-storm cloud and creates a funnel cloud
the storm is classified as a tornado when the funnel touches the ground

38. the funnel cloud is only visible because of the debris being lifted from the ground

39. More tornados occur in the US than anywhere else on Earth.
Tornado Alley is the name given to the area in the Midwest that experiences the most tornadoes.

40. Storm Chasers
people that observe and record weather data about tornadoes as they are happening

41. tornados are classified according to wind speed and damage F0-F5
a tornado watch means weather conditions are favorable for tornados to form in the area
a tornado warning means tornados have been sighted