Predicting Heat Waves Using the Ocean

Heat wave illustration (Source: U.S. National Weather Service, http://www.srh.noaa.gov/jetstream/global/hi.htm)

Heat waves in the United States have become a problem over the past decade. According to the Center for Disease Control and Prevention, from 1999 to 2010, more than 600 people on average died annually in the US from heat-related causes. Relief, though, seems to be emerging. New research published this past week suggests that major heat waves in the US may be predictable two months before they hit. Climatologists from the National Center for Atmospheric Research combed through decades of data and connected sea surface temperature patterns in the North Pacific Ocean to subsequent extremely hot days occurring around 50 days later. The physical connection between sea surface temperature and hot days, though, remains unknown. Scientists think one possibility is that the sea temperatures may be affecting the movement of the jet stream, a fast and narrow air flow in the upper atmosphere that planes often hitch a ride on. The jet stream also helps organize the high-pressure air masses that typically cause extreme heating, so it's a likely suspect for connecting sea surface temperatures to future heat. The connection, though, as the researchers stress, is not a guarantee; the sea surface temperature pattern indicates that a heat wave is likely to occur, not that it definitely will. Still, the correlation is strong enough to make this research invaluable for forecasting and protecting those who may be exposed to extreme heat. 
 

Sean Faulk
Staff Writer, Signal to Noise Magazine
Graduate Student, Earth, Planetary, and Space Sciences

References:

McKinnon, K.A., et al. (2016). Long-lead predictions of eastern United States hot days from Pacific sea surface temperatures. Nature. DOI: 10.1038/ngeo2687