New, Better Weather Predictions

Researchers have found a long-lead early warning system—up to 50 days in advance–for extreme heat patterns.

By Nancy Dorman-Hickson


Scientists may have discovered a means of predicting extreme heat waves in the Eastern U.S. some 30 to 50 days before the event begins.

In a study by the National Center for Atmospheric Research (NCAR), the presence of warmer-than-average water against cooler-than-average seas in the north Pacific Ocean tends to indicate an increased chance of summertime heat in an area that includes much of the U.S. Midwest and the East Coast.

Researchers have drawn correlations between that pattern of sea temps—called the Pacific Extreme Pattern—and temperatures 11.7 degrees F (6.5 C) hotter than average. Data was collected from 1,613 weather stations across the Eastern U.S. between 1982 and 2015, as well as daily sea surface temperatures for the same time period. Typical forecasts predict such climatological events only seven to 10 days in advance.

“By identifying a source of long-lead predictability in the Pacific Ocean, we are able to provide skillful forecasts out to a horizon of more than a month,” says the University of Washington’s Andrew Rhines, one of the study’s authors.

In addition to providing early warnings to city planners, utility companies and others, Rhines says, “This gives farmers much earlier warning of weather risks, allowing them to take steps to mitigate the effects of high temperatures on summer crops and livestock.”