Predicting heat waves just got easier. While local meteorologists might still struggle with some accuracy when discussing the next day’s temps, scientists are now confident that they can predict deadly summer heat waves well in advance, hopefully providing emergency personnel and farmers time to prepare.
Reports the New York Times on March 28: “The key to such an advance forecast, scientists said, is the occurrence of a distinctive pattern of water temperatures across a wide stretch of the North Pacific Ocean. While the existence of the pattern does not guarantee that a heat wave will occur, it significantly increases the odds of one happening as much as 50 days later.”
According to the CDC, heat waves often lead to heat stroke, defined as a “heat-exposed individual whose core temperature is 105 degrees or greater.” Heat stroke has a high death-to-case ratio, and those most susceptible include the elderly, residents of poorer inner city areas, individuals on certain medications and those confined to a bed.
A CDC Heat Prevention Guide noted that heat waves caused 7,415 heat-related deaths in the United States from 1999 to 2010. One of the deadliest heat waves hit the Chicago area in 1995, when temps well over 100 degrees led to 739 heat-related deaths over the course of a few days.
The recent heat wave study, published this week in the journal Nature Geoscience, reviewed historical data from US weather stations recorded from 1982 up through last year.
“The pattern popped out at us really clearly,” commented Karen A. McKinnon, a researcher at the National Center for Atmospheric Research, in Boulder, Colo., and the lead author of the study. McKinnon said the pattern was detectable “up to seven weeks before” the heat waves hit populated areas.
“We’ve really gone in with a focus on these high-temperature extremes,” Dr. McKinnon said. “If we do see the pattern, we can say how similar is this to the one that leads to a heat wave.”
The hope is that by identifying and tagging these patterns, advance forecasters will be able to alert individuals – who can then prepare “cooling centers,” like the ones opened in Los Angeles a few years ago. City officials would be able to step up programs to assist the homeless and elderly, and farmers would be able to plan for advance crop irrigation.
“Whatever mechanisms ultimately lead to the heat wave also leaves a fingerprint of sea surface temperature anomalies behind,” McKinnon said. “We found that we could go back as far as seven weeks and still predict an increase in the odds of future heat waves. What’s exciting about this is the potential for long-range predictions of individual heat waves that gives society far more notice than current forecasts.”