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Earth Science
Grade 6-11
Storm Types & Severe Weather Cheat Sheet
A printable reference covering thunderstorms, tornadoes, hurricanes, blizzards, fronts, watches, warnings, and severe weather safety for grades 6-11.
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Earth Science: Storm Types & Severe Weather covers the main kinds of dangerous weather and the conditions that create them. Students need this cheat sheet to compare storms, recognize warning signs, and connect weather maps to real events. It also supports safety decisions by explaining the difference between outlooks, watches, and warnings. The topic is important because severe weather can change quickly and affects communities, travel, and daily life.
Key Facts
- Thunderstorms form when warm, moist air rises into unstable air, cools, and condenses into tall cumulonimbus clouds.
- A thunderstorm needs moisture, lift, and instability, often written as severe storm setup = moisture + lift + unstable air.
- Lightning is an electric discharge caused by charge separation inside a cloud or between a cloud and the ground.
- A tornado is a violently rotating column of air connected to a thunderstorm and touching the ground.
- Hurricanes form over warm ocean water, usually at least 26.5°C, when rising moist air and low pressure organize into a rotating storm.
- A blizzard is defined by sustained winds or frequent gusts of at least 35 mph, falling or blowing snow, and visibility of 1/4 mile or less for at least 3 hours.
- A watch means severe weather is possible in the area, while a warning means severe weather is occurring or expected very soon.
- The safest place during a tornado is a basement or a small interior room on the lowest floor, away from windows.
Vocabulary
- Thunderstorm
- A storm with lightning and thunder that forms in cumulonimbus clouds, often with heavy rain, wind, or hail.
- Tornado
- A narrow, violently rotating column of air that extends from a thunderstorm to the ground.
- Hurricane
- A large rotating tropical storm with sustained winds of at least 74 mph that forms over warm ocean water.
- Front
- A boundary between two air masses with different temperature, humidity, or density.
- Storm Surge
- An abnormal rise of ocean water pushed toward shore by strong winds and low pressure during a tropical storm or hurricane.
- Severe Weather Warning
- An alert that dangerous weather is happening or is expected soon in a specific area.
Common Mistakes to Avoid
- Confusing a watch with a warning is wrong because a watch means conditions are possible, but a warning means the threat is happening or imminent.
- Thinking all rotating clouds are tornadoes is wrong because a tornado must be connected to the cloud and in contact with the ground.
- Judging hurricane danger only by wind speed is wrong because storm surge, flooding rain, and tornadoes can also cause serious damage.
- Opening windows during a tornado is wrong because it wastes time and increases danger from flying glass and debris.
- Assuming snow alone makes a blizzard is wrong because a blizzard requires strong winds, very low visibility, and at least 3 hours of those conditions.
Practice Questions
- 1 A storm has sustained winds of 82 mph over warm ocean water. What type of tropical cyclone is it, and which wind speed threshold did it pass?
- 2 A winter storm has wind gusts of 40 mph, visibility of 1/8 mile, and blowing snow for 4 hours. Does it meet the definition of a blizzard? Explain using the conditions.
- 3 A county receives a tornado watch at 2:00 p.m. and a tornado warning at 3:15 p.m. What should people do differently after the warning is issued?
- 4 Why can flooding from a hurricane be dangerous even after the strongest winds have weakened?