U.S. drought footprint continues to shrink
March 4, 2016
During the 4-week period ending on March 1, 2016, contiguous U.S. drought coverage fell to 14.30 percent—a decrease of 1.18 percentage points. This also represents the smallest areal coverage of U.S. drought in nearly 5.5 years, since October 12, 2010. The U.S. drought minimum of 2010—7.74 percent coverage on July 6—occurred in the wake of the most recently completed El Niño, which lasted from the summer of 2009 to the spring of 2010.
Since mid-October 2015, stormy weather in many parts of the country—in part driven by a strong El Niño—has significantly reduced the U.S. drought footprint from 34.78 to 14.30 percent—a drop of 20.48 percentage points.
In February, however, disappointingly dry weather covered much of the West. For example, the average water content of the high-elevation Sierra Nevada snowpack was nearly steady during February at 20 to 22 inches, with few storms hitting key watershed areas. Since February is typically an important month for Sierra Nevada snowpack accumulation, the percent of average snowpack dropped from about 115 percent of average on February 1 to just 85 percent by month's end.
On March 1, more than one-third (36 percent) of the western U.S. remained in drought, down from 57 percent in early October 2015. Most (95 percent) of California was still in drought on February 2, down 2 percentage points from the beginning of the water year on October 1, 2015. However, California's coverage of exceptional drought (D4) has fallen from 46 to 38 percent since October 1. Farther north, extreme to exceptional drought (D3 to D4) in Oregon and Washington has been eradicated since the beginning of the water year—down from 67 and 68 percent, respectively.
On March 1, drought was affecting just 10 percent of the U.S. cattle inventory, down from an autumn 2015 peak of 27 percent.
On March 1, the portion of the U.S. winter wheat production area in drought stood at 6 percent, down from an autumn 2015 peak of 29 percent on October 20. At the end of February, USDA/NASS rated more than two-thirds of the winter wheat in good to excellent condition in several major production states, including Ohio (72 percent), South Dakota (69 percent), Oklahoma (68 percent), and Indiana (67 percent). Across the central and southern Plains, however, February warmth caused winter wheat to prematurely break dormancy, leaving the crop susceptible to spring freezes. The northern Plains' wheat has also lost some winter hardiness and is exposed to potential spring weather extremes. In addition, pockets of abnormal dryness (D0) have developed across the Plains, with D0 expanding to cover 25 percent of Texas and 21 percent of Oklahoma by March 1—up from 2 and 0 percent, respectively, on February 2. In Texas, only 40 percent of the winter wheat was rated in good to excellent condition at the end of February, down from 49 percent a month ago.
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On March 1, the Midwest remained free of drought, continuing a 9-week trend that began on January 5, 2016. The last time the Midwest was free of drought (D1 to D4) for a longer period was 2005, when there was no drought coverage for 12 consecutive weeks from February 15 to May 3. In addition, U.S. Drought Monitor coverage of Midwestern abnormal dryness (D0) had never dropped below 1 percent until February 9, 2016, and currently stands at a record-low 0.90 percent.
Weather outlook: Big changes are coming to northern and central California for the weekend and early next week. From March 3 to March 7, five-day precipitation totals could reach 4 to 10 inches or more in parts of northern and central California and 2 to 4 inches in the Pacific Northwest. Generally light precipitation will develop across much of the remainder of the western U.S. By early next week, a complex weather system will begin to evolve across the nation's mid-section, eventually leading to widespread precipitation, gusty winds, and possibly severe thunderstorms spreading eastward from the Plains.