What Is a Derecho? 2025 Updated Criteria
Learn about the updated 2025 derecho definition, including new criteria like hurricane-force gusts, storm length, and what qualifies a storm as a true derecho.
Weather Why’s
What is a Microburst?
Learn what a microburst is, how it forms, and why it's dangerous. Discover key differences from tornadoes and how to stay safe during severe storms.
What is a Mesoscale Convective System (MCS)?
What is an MCS? Discover how these massive storm clusters form, why they last for hours, and the dangers they bring — from floods to fierce winds.
What is a Squall Line?
Learn what a squall line is, how it forms, the hazards it brings—including strong winds, heavy rain, hail, tornadoes—and why shelf clouds are a warning sign.
What is SKYWARN?
Learn about SKYWARN, the National Weather Service’s volunteer program that trains storm spotters to report severe weather. Discover how to join, what spotters report, and why it saves lives.
Shelf Cloud vs. Wall Cloud: What is the Difference
Often confused, there is a difference between a wall cloud and a shelf cloud. Here is how to tell them apart.
Building the Ultimate Severe Weather Preparedness Kit
Be ready for storms with a severe weather preparedness kit. Learn what essentials to pack—food, water, radios, and more—to keep your family safe.
Will Snow Stick If It’s Above Freezing? Here’s What Science Says
How does the snow stick when the surface is above freezing?
When is the First Frost in Iowa?
With the temperatures beginning to cool, the first frost is not far off.
What Causes Thunder & Lightning?
Unravel the magic of lightning and thunder! Discover how these electrifying phenomena form, the scorching heat of lightning, and the awe-inspiring speed that leaves us in wonder. A natural spectacle like no other.