WSP04710

• File Number: 8056
• Description: Drought Preparedness
• State: CO
• Basin: Statewide
• Date: 6/1/1997
• Author: Donald Wilhite
• Title: Improving Drought Management in the West
• Water Supply Pro - Doc Type: Report/Study

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The Climatology of Drought in the West: 1895 to 1996

Drought conditions abated in early 1987 but reappeared quickly in the spring.
Moderate to extreme drought was widespread over the Western United States
by August, and moderate drought reappeared in the Southeast and spread
west into the Midwestern Corn Belt States. Pockets of severe to extreme
drought developed in portions of the Tennessee, Ohio, and Mississippi River
Valleys, a forewarning of events to come. By the end of 1987, approximately
17 percent of the Nation was experiencing severe to extreme drought.

By April 1988, drought conditions in the West had deteriorated significantly,
Severe to extreme drought affected all of California, Oregon, Washington, and
Idaho; northern portions of Utah; and western portions of Wyoming and
Montana, In addition, moderate drought had spread into eastern Wyoming
and Montana. Significant pockets of moderate to severe drought had fonned
in Minnesota, eastern portions of North Dakota and South Dakota, and New
England. Moderate to extreme drought persisted in the Southeast. By late
May, drought in the West, northern Great Plains, and upper Midwest had
intensified and spread into adjacent States. The drought area in the
Southeast also began to spread northward into Indiana, Ohio, Illinois, and
Iowa. By late July, the intensity had worsened, and the spatial coverage had
increased. The drought areas in the West and Midwest were joined, and
moderate drought had spread throughout the South and into eastern Texas.
Severe drought continued in New England, and parts of the mid-Atlantic
coast were also affected. By August, more than 35 percent of the Nation was
experiencing severe to extreme drought,

Dry conditions moderated during the fall and winter months, as precipitation
returned to nonnal for some areas and water demand subsided. By May
1989, the drought area was reduced to < 20 percent but quickly increased to
nearly 30 percent by late summer. The most severely affected areas were
California, Nevada, Arizona, Utah, and Wyoming, and parts of Colorado and
New Mexico, Portions of the Pacific Northwest were also affected. The
drought that had occurred in the Midwest and Northern Plains States in 1988
shifted south and west in 1989 to affect Kansas, eastern Nebraska, Iowa, and
northern Missouri. For the most part, drought conditions in the Southeast,
mid-Atlantic, and New England States disappeared. The area in severe to
extreme drought leveled off at about 25 percent in 1990 and continued at that
level through 1991. The principal areas affected were the Western States and
portions of the northern Great Plains. A significant decline in the drought
area occurred in early 1991 (to < 10 percent of the Nation). It peaked at

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