Research In Action

Extreme Weather

Weather affects us on a daily basis: from planning what to wear or when to plant crops, to deciding when and where to go on vacation, we are constantly looking for weather information.

The Sun powers our weather. At any given moment, it is shining on half of our spinning planet. But, as anybody who has walked across a dark asphalt parking lot knows, heating from the Sun isn’t the same everywhere.

This uneven heating is what drives weather. Think of the churning motion of water boiling on a hot stove. This process, known as convection, occurs when air over warmer surfaces heats and rises. Cooler, denser air flows in to replace it. These basic motions ultimately generate wind, rain, and other kinds of weather.

Sometimes, conditions come together in a way that causes weather extremes: droughts, heat waves, severe storms, hurricanes and tornadoes. These events can cost lives and livelihoods, and cause tremendous disruption. We study weather and climate to make forecasts more accurate, to help get people out of harm’s way and to minimize the impact of these events on society.

Economic Impacts

A single severe weather event in a small area, such as a tornado, can cause a billion dollars of damage. Larger and longer-lasting weather patterns like heat waves can affect human health, agriculture, ecosystems, transportation, manufacturing, and other industries. Localized or widespread, the impacts of these extreme events can be expensive—Hurricane Katrina is estimated to have cost over $95.5 billion[i] (2012 U.S. dollars) and damage from the Joplin tornado is estimated around $3 billion.[ii]


Accurately predicting the time and location of severe weather events can help save lives and provide more effective emergency relief. Scientists use supercomputers to model and generate forecasting tools. The more powerful the computers, the faster scientists can work to produce the information in time to make a difference.

Weather Advisories

When severe or dangerous weather is forecast, weather advisories help to alert the public about conditions. A weather “watch” means there is a chance—usually a good chance—that dangerous weather could happen. A weather “warning” means dangerous weather is already happening near you, and you should immediately take action to stay safe, like finding a tornado shelter or evacuating to higher terrain to avoid a flash flood.

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Inside the NWSC

A modern smartphone is far more powerful than NCAR’s first supercomputer, known as the Cray-1A, acquired in 1977. Each replacement machine has been many times more powerful than its predecessor. Computer technology usually doubles in power about every 18 months, a rate of growth known as Moore’s Law.