Flash Drought in U.S. Explained in 21 Seconds

Flash Drought

This animation shows the rapid progression of the U.S. drought during the late spring into mid August, based on U.S. Drought Monitor maps.

As of August 14, about 78 percent of the U.S. was experiencing some form of drought conditions. This was a stunning reversal of fortune from just a few months earlier, when it looked like corn growers were going to have an historically large harvest and drought was limited to the southern tier of the country. Scientists trace the drought's origins to a combination of factors, ranging from La Niña conditions in the Pacific Ocean along with a warmer than average Atlantic Ocean, a setup which tends to favor drought in the U.S., to a very mild winter that left little snowpack to help keep soils moist in the spring. Massive heat waves brought blistering heat during March, June and July, turbocharging the process of evaporating water out of soils and plants, and leading to what meteorologists call a “flash drought.” Rather than develop gradually, as is more typical with drought conditions, this drought came on with stunning swiftness.

Climate outlooks for the September through November period call for some improvement across parts of the drought region, such as the Midwest and Ohio Valley, while the High Plains and most of the West continues to see severe drought conditions. With ocean temperatures warming up in the eastern tropical Pacific — a harbinger of El Niño — the fall forecast is more uncertain than usual, so it's possible that drought relief will be more widespread than currently forecast.