U.S. Drought Monitor

 (through 2/15/11)
Data Source(s): U.S. Department of Agriculture, National Drought Mitigation Center, National Oceanic and Atmospheric Administration

There has been little change in the extent of drought conditions across the western U.S. over the past 30 days. Overall, only 27 percent of the 11 western U.S. states, excluding Hawaii and Alaska, are observing abnormally dry conditions or worse; only about 9 and 4 percent is classified with moderate and severe drought, respectively. The majority of the area classified with abnormally dry conditions or worse is located in Arizona and New Mexico, where La Niña-induced dry conditions have reigned. A persistent northerly winter storm track has caused dry conditions in the Southwest, but also has contributed to above-average precipitation in the Pacific Northwest and much of the northern and central Rocky Mountains. A small area of abnormally dry conditions has developed over northern California, where below-average precipitation has fallen over the past month. Most of California and Utah and all of Nevada are drought free, in part because very intense storms walloped these regions in December. In parts of Southern California and Nevada, these storms alone delivered nearly a year’s worth of precipitation.

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