DROUGHT CONDITIONS INTENSIFY IN SOME WESTERN STATES WITH LITTLE CHANCE OF MAJOR RELIEF
February 11, 2003 — Dried-up reservoirs and wells. Parched pastures. Failed crops. Dust storms. These images are reminiscent of some of the epic droughts in years past but also portray drought conditions since last summer. These conditions have left several Great Plains and Western States with one of the worst droughts in the last 108 years. Increased precipitation by late winter (February and March) may not arrive in time to make a significant dent in these conditions, according to the NOAA National Weather Service.
“From year-to-year, it is not unusual for some area of the country to be in drought at some point," said Douglas LeComte, drought specialist with the NOAA Climate Prediction Center. “However, the extent of last summer’s serious drought conditions measured by the Palmer Drought Indices has not been seen since the mini-dust bowl drought of the mid-1950s.” Even now, over one-fifth of the nation is in severe drought.
In 2002, Colorado measured its driest calendar year since records began in 1895. Also, Nebraska, Wyoming, and Nevada recorded their third driest year. Last summer, the Palmer Drought Index—a measure of relative soil dryness or wetness—in Colorado, Wyoming and Arizona reached extremes not seen in 100 years. Although recent rain and snow has improved drought indices in parts of the West, this winter’s precipitation totals have done little to ease the hydrological drought, as snow pack has been below normal in every western state except California and reservoirs have been below normal in every western state.
CPC scientists attribute the drought in parts in the West to three dominant climate features. La Niña, which is associated with high pressure and below-normal precipitation over both the Southwest and Southeast, ended in early 2001, but played a role in initiating some of the drought that lingers today. The current El Niño also has favored continued drought in the northern Rockies and surrounding areas. Third, a large-scale, sea-surface temperature pattern that has persisted since 1998, with record warmth in the western Pacific and cool waters in the eastern Pacific, has been associated with drought in many parts of the world, including the United States.
El Niño is usually associated with above-normal rain and snow across the Southwest, but this wet pattern has been slow to kick in during the first half of the 2002-03 winter, allowing extreme drought to persist or even intensify across the region.
Long-range forecasters at the CPC still expect increased precipitation in the Southwest by late winter (February and March). However, confidence is decreasing among the CPC forecasters that enough rain and snow will occur during February through April to make a significant dent in the drought before the usual hot, dry weather arrives in late spring.
NOAA plans to release the U.S. spring outlook on March 20, 2003.
The NOAA Climate Prediction Center, one of the NOAA National Centers for Environmental Prediction, is part of the NOAA National Weather Service. The Climate Prediction Center assesses national drought conditions as well as predicts and monitors El Niño. The center also produces the nation’s official long-range outlooks and medium-range weather forecasts.
NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation’s coastal and marine resources. NOAA is part of the Department of Commerce.