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Published March 27, 2013
U.S. Drought Monitor(data through 3/19/13)
Data Source(s): U.S. Department of Agriculture, National Drought Mitigation Center, National Oceanic and Atmospheric Administration
The winter storm track started to move north during the last 30 days, signaling the transition from winter into spring for the Southwest. This transition often occurs at this time of year, although there is some indication that it has been occurring earlier in the year in recent decades. This northward displacement favors precipitation in northern states, and parts of Washington, Idaho, and Montana experienced the bulk of the precipitation in the West, with areas recording above-average rain and snow in the past month. These areas also remain drought-free, according to the March 19 update of the U.S. Drought Monitor (Figure 3). Moderate to exceptional drought conditions continue in the rest of the western U.S. south of southern Oregon and Wyoming. Parts of Wyoming, Colorado, and New Mexico, which have had mounting precipitation deficits in the last two years, are still experiencing the most extreme drought conditions. In the last month, the geographic pattern and intensity of drought in the western U.S. did not substantially change. At least moderate drought covers more than 60 percent of the West, with about 25 and 16 percent classified with severe and extreme drought, respectively. In coming months, the seasonal drought forecast suggests that much of the current drought will continue to persist. The last time moderate drought covered less than 50 percent of the West was in May 2012, and the last time extreme drought blanketed more area than it currently does was in late 2004, according to the U.S. Drought Monitor.
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.
The best way to monitor drought trends is to pay a weekly visit to the U.S. Drought Monitor website:
Southwest Climate Outlook Staff
- Michael Crimmins, UA Extension Specialist
- Stephanie Doster, Institute of the Environment Editor
- Gregg Garfin, Founding Editor, Institute of the Environment
- Zack Guido, Managing Editor, CLIMAS Associate Staff Scientist
- Nancy J. Selover, Arizona State Climatologist
- Jessica Dollin, CLIMAS Publications Assistant
- Dave Dubious, New Mexico State Climatologist
Please direct your Southwest Climate Outlook comments and suggestions to Zack Guido.
The CLIMAS Web site contains official and non-official forecasts, as well as other information. While we make every effort to verify this information, please understand that we do not warrant the accuracy of any of these materials.... Read full disclaimer