The Weather Notebook: Heat Wave Warning System

Heat Wave Warning System
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Dave Thurlow, Host

Hi, I'm Dave Thurlow and this is The Weather Notebook. Did you know that more people die from heat in the U.S. than from any other kind of weather? Just 4 years ago, a heat wave killed more than 500 people in Chicago. We know that moisture in the air makes a hot day feel more uncomfortable. But science is now showing that it's not just the heat OR the humidity. Several other things contribute to the worst heat waves.

Professor Laurence Kalkstein, at the University of Delaware, has come up with a new warning system for these killer hot spells. The main tool now used by the National Weather Service is the apparent temperature or heat index, a blend of temperature and humidity. But this doesn't tell the whole story.

For instance, the sunshine beating down on a clear day will make you feel worse and make cities heat up more than they would on a cloudy day, even if the heat index is the same. When the wind's blowing, your skin dries out faster and you suffer more from the heat. And if a heat wave strikes in June, you'll be less acclimated and more vulnerable than if it waits till August. All these factors have been considered in Kalkstein's system.

It's already being used in Philadelphia and Washington, and the United Nations is helping bring the system to Italy. At your home, you can use your own warning system when the mercury rises - common sense. Drink lots of water, stay out of the sun, use an air conditioner or a fan, and keep in touch with the older folks in your life. They're the most common prey of a killer heat wave.

Thanks to contributing writer Bob Henson. The Weather Notebook is underwritten by Subaru with major support provided by the National Science Foundation.