ENVIRONMENT
Use our activity to create your own weather map, and take a look at our own with today’s MapMaker Interactive map.
Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Discussion Ideas
- Severe weather has swept through the southern Great Plains of the U.S.—floods, tornadoes, hail, and strong winds. What is a flood? Read through our encyclopedic entry for some help.
- A flood happens when water overflows or soaks land that is normally dry. Usually, a flood occurs as river or reservoir overflows its banks.
- What are some rivers or watersheds that have been flooded recently? Use the zoom feature on today’s MapMaker Interactive map for some help.
- Houston: San Jacinto River
- San Marcos: Blanco and Comal Rivers
- Austin: Colorado River
- Dallas: Trinity River
- What is a tornado? Take a look at our “Forces of Nature” interactive for some help.
- A tornado is a violently rotating column of air that forms at the bottom of a cloud and touches the ground.
- Are the southern Great Plains a part of “Tornado Alley”, a region recognized for its frequent, violent wind storms? Take a look at the “Tornado Alley” bookmark on today’s MapMaker Interactive map, or read through this blog post for some help.
- Yes. The central and southern Great Plains experience some of the most violent storms in Tornado Alley.
- What is hail? Take a look at our short encyclopedic entry for some help.
- Hail is formed when drops of water freeze together in the cold upper regions of thunderstorm clouds. These chunks of ice are called hailstones. Most hailstones measure between 5 millimeters and 15 centimeters in diameter, and can be round or jagged.
- Does Tornado Alley experience frequent hailstorms?
- Yes. In fact, according to our encyclopedic entry, the Great Plains region is also nicknamed “Hail Alley.”
- What are gale-force winds? Take a look at our excellent (and downloadable!) illustration of the Beaufort scale for some help.
- A gale is simply a very strong wind, usually one blowing more than 50 kilometers per hour (25 miles per hour).
- What other extreme weather elements do you think the southern Great Plains probably experienced recently?
- Residents of the southern Great Plains may have experienced lightning, downbursts, and possibly even waterspouts.

TEACHERS’ TOOLKIT
CNN: Texas floods: More rain on the way as 13 people remain missing
NOAA/National Weather Service: Storm Prediction Center
The Weather Channel: Tornado Central
Nat Geo: Severe Weather during Memorial Day Weekend map
Nat Geo: Create a Weather Map
Nat Geo: What is a flood?
Nat Geo: Forces of Nature interactive
Nat Geo: Are Storms Redefining Tornado Alley?
Nat Geo: What is Hail?
Nat Geo: What is the Beaufort Scale?
Nat Geo: What is wind?