More than 20 U.S. cities are using a new forecasting system to predict extreme summer heat more accurately to warn residents sooner when conditions threaten to turn deadly.
The “heat-health warning” system was pioneered in Philadelphia after 118 people died during a heat wave in 1993. As the nation marks Memorial Day as the traditional start of the season, the system is likely to get a summer workout. The National Weather Service predicts above-normal summer temperatures in much of the country, especially the Southwest, South and East.
Severe heat causes more weather-related deaths in the USA than all other weather phenomena combined, according to the Centers for Disease Control and Prevention. University of Delaware climate researcher Laurence Kalkstein, co-inventor of the heat-health system, estimates 1,500 U.S. deaths a year because of heat.
The fierce heat wave in Europe in 2003 killed as many as 30,000 people. “It could happen here, with disastrous consequences,” Kalkstein said. In a study to be published later this year, he calculates that more than 2,500 people in New York City would have died of heat-related causes if that heat wave had struck here.
The weather service adds three cities to the heat-health system this year: Washington, Seattle and Portland.
The new system allows forecasters to send out health alerts for heat with more precision and speed. They issue advisories as before: Five-day “outlooks,” a “watch” that covers 24 to 48 hours if conditions worsen and a “warning” for 24 hours or less in case of extreme heat with potential to sicken or kill.
Kalkstein credits the heat-health system with saving at least 117 lives in Philadelphia between 1995 and 1998, when an early version was first adopted. He said calculations since then show more than 270 lives were saved through 2003. The alerts led the city to set up shelters and hotlines and volunteers to check door-to-door on the elderly or ill.
The weather service wants to put the system in the nation’s 100 largest cities, which would cost a total of $2.5 million, because urban areas are at greater risk to severe heat. They often have older houses with less insulation and black-tar rooftops.
Kalkstein said cities in temperate climates, not known for severe heat, can suffer even in a moderate hot spell because people aren’t acclimated to sudden high temperatures and may not have air conditioning. He said a heat wave in Seattle in 1992 contributed to as many as 60 fatalities there.
“It’s an eye-opener,” said Ted Buehner, warning coordination meteorologist for the weather service in Seattle. The city averages only three days a year with highs of 90 degrees or more. “When I first heard about this program, I almost blew it off. Once I saw the statistics, it was kind of, ‘Well, duh.’ “