Slim Odds of Ending the Drought this Year

The worst drought in more than 50 years has been hammering much of the continental U.S. since at least last spring, and NOAA’s Climate Prediction Center says that while some areas will see some relief in the next few months, most areas will likely remain under persistent drought well into the winter. That doesn’t mean the chances of emerging from this epic dry spell are zero — but in many places, they’re pretty close to it.

The map above shows how likely it is that a given region will emerge from drought by the end of the year. The darker the color, the less likely it is that this will happen. The darkest brown areas, representing more than 40 percent of the continental United States, have less than a five percent chance of recovering from drought by the end of the year, according to the National Climatic Data Center (NCDC).

NCDC updates these scenarios monthly, calculating the statistical probability that the drought will end over the course of the next of 1,2,3, and 6 months. The complex calculations take into account thePalmer Hydrological Drought Index, as well as local climatological conditions in a given region. Details of these calculations are explained in depth in a paper by Tom Karl et al. 1987.

According to a special report from the U.N. Intergovernmental Panel on Climate Change, in the coming decades, droughts in general are likely to be more intense, come more often, and last longer as the world continues to warm.