News•November 15, 2012

Winter Storms Bring A Little Relief to U.S. Drought Areas

By Dan Yawitz

Nearly 60 percent of the continental U.S. is still under drought conditions, according to the latest update from the U.S. drought monitor. While the past week brought rain to many of the afflicted regions, it may not be nearly enough to compensate for the historically low levels of rainfall seen across the country since early spring. However, the little rain that fell was enough to prevent conditions from deteriorating in most places.

The total percentage of area affected by drought dropped slightly in the past week, from 59.48 percent to 58.83 percent. This is little change from the end of the summer, when just more than 65 percent of the lower 48 states was under drought conditions categorized as “severe” or worse.

U.S. Drought Monitor as of November 13, 2012.
Click on image for a larger version.Credit: NOAA/USDA.

The biggest improvements this week occurred after a slow-moving winter storm passed over the Northwest and Rocky Mountains. Much of that precipitation fell in the mountains, but it was still enough to relieve northern and western Montana of its short-term rainfall deficiencies, and prompt one-category improvements in nearby North Dakota.

The remnants of this storm also brought up to 1.5 inches of rain to areas of the Midwest that stretched north from Kansas to Michigan, and east from Missouri to Indiana. While this may provide some short-term relief to the afflicted topsoil, it may not be enough to alleviate the long-term hydrologic impacts brought on by months of low rainfall.

Similarly, the small amount of rain that fell in eastern Oklahoma may have saved the winter wheat crop for another few days, but beyond that is uncertain if the region sees no rain in the coming weeks.

Other parts of the country were not as lucky. Western Nebraska, Kansas, and the Oklahoma panhandle, which have faced some of the worst impacts of the drought this year, saw less than half an inch of rain this week. Texas saw a slight deterioration into moderate drought, which extended into southern Louisiana. Parts of hard-hit Georgia, which were 5 inches of rain below the normal as of September 1, received only 0.03 inches of rain since last week, allowing much of the Southeast to stagnate and intensify.

In the High Plains, this week’s map showed 93.88 percent in moderate drought or worse, down from 96.46 percent the week before, a small increase in severe drought, and small decreases in extreme and exceptional drought. However, the Southeast, which has also experienced a long-running drought, the map showed 25.10 percent in moderate drought or worse, an increase from 22.90 percent last week.

The costs of this drought have been substantial. Oklahoma State’s Agricultural Economics department estimated Oklahoma’s drought costs from the 2011-12 water–year, which ended in September, at $4.27 million. The losses from across the country are estimated to be in the billions. The USDA will release its official cost estimate in early January.