Recent Conditions
Published December 19, 2011

U.S. Drought Monitor

 (data through 12/13/11)
Data Source(s): Data Sources: U.S. Department of Agriculture, National Drought Mitigation Center, National Oceanic and Atmospheric Administration

In the West, drought is confined to the Southwest U.S. due to the moderate to strong La Niña event that brought very dry conditions to the region during last winter (Figure 3). Drought is improving, however. The jet stream had a more southerly trajectory recently and ferried several early winter storms through Southern California and Arizona. This, consequently, has caused storms to be scant in the Pacific Northwest and northern California. Precipitation in northern California, Oregon, and eastern Washington in the past 30 days has been less than 25 percent of average, causing abnormally dry conditions in these regions. The northern Rockies also have been drier than average.

Map of United States Drought Monitor
Notes:

The U.S. Drought Monitor is released weekly (every Thursday) and represents data collected through the previous Tuesday. The inset (lower left) shows the western United States from the previous month’s map.

The U.S. Drought Monitor maps are based on expert assessment of variables including (but not limited to) the Palmer Drought Severity Index, soil moisture, streamflow, precipitation, and measures of vegetation stress, as well as reports of drought impacts. It is a joint effort of several agencies.

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