Extreme Weather Events

1. Tropical cyclones require ocean temperatures higher than _____ degrees.
5. In April, 2011, one stor system caused 355 tornadoes to form between ______ and southern Canada.
10. Hurricanes, which form north of the equator, spin _____.
12. A ______ has winds between 39 and 74 miles per hour.
14. The boundary between warm and cold air masses is called a ______.
16. Tornadoes have happened on every continent except for ________.
17. The deadliest natural disaster in US history was a hurricane in this town in Texas.

1. The widest tornado ever recorded happened in this city.
2. Most tornadoes last less than _____ minutes.
3. _____ air is required to lift a vortex into a vertical funnel cloud.
4. The calm center of a tropical cyclone is called the _____.
6. The horizontal tube of spinning air that forms underneath a supercell
7. The costliest tornado ever recorded caused almost $3 billion in damage in this city.
8. It takes 3 ingredients (freezing temperatures, moisture, and lift) to form this kind of storm
9. ______ happens when warm, moist air from the south and cool air from the north collide.
10. When _____ air descends, it gives strength to a growing vortex.
11. The deadliest blizzard ever happened in this country in 1972
13. There is a tiny bit of _____ in the center of every snowflake.
15. The tornado with the longest path ever happened in this month in 1925.