Residents of and visitors to the eastern US may soon be able to better deal with and avoid punishing summer heat waves.
Research published last week has indicated it may be possible to predict the occurrence of heat waves on the eastern seaboard almost two months in advance. The research, published in the journal Nature Geoscience, suggests that heat waves in the eastern US tend to occur some six to seven weeks after an unusual temperature phenomenon on the other side of the world.
“Our predictions are not deterministic, and so do not provide a guarantee that a hot day will occur,” says Karen McKinnon, post-doctoral fellow at the National Center for Atmospheric Research and lead author of the study. “Rather, we can make predictions such as the odds-in-favour of a hot day are one-in-two.” Knowing the chances of such an event are higher than usual will help emergency planners, medical service providers and farmers plan for a heat wave.
The Pacific Extreme Pattern, as it’s been dubbed, occurs in an area of the ocean near Hawaii. In the south of this area, water surface and upper atmospheric temperatures rise abnormally, while the opposite occurs in the area’s north, when temperatures are much cooler than normal. Data gathered over a 33 year period suggests that heat waves in the inner east of the US are much likelier to occur within a 40 to 50 day window following such an event. Such abnormal temperatures tend to trigger a cascade of weather effects that spreads eastward over the US, grinding to a halt above the inner east, bringing a high pressure zone marked by high humidity and intense heat.