September 26, 2002
UNL Climatologist Sees Little Relief From Drought Conditions This Winter
LINCOLN, Neb. — Most of Nebraska will be dryer than normal this winter with normal to above normal temperatures, a University of Nebraska-Lincoln climatologist predicts.
Although recent rains in parts of Nebraska helped ease this summer's drought, most of the state remains dry. Agricultural Climatologist Steve Hu expects that dry pattern to continue statewide.
"I wish I could say we are going to see more precipitation this winter, but that's not what my analysis shows," the Institute of Agriculture and Natural Resources scientist said.
Hu uses sophisticated statistical analysis to predict precipitation anomaly patterns. Anomalies are important because they indicate departures, or variations, in long-term averages, he said.
His predictions are based on his research, which analyzed 112 years of precipitation data and identified precipitation variation patterns throughout most of the last century.
According to his analysis, this winter's temperatures in northern Nebraska should be slightly above normal with near normal temperatures in the southern half of the state.
"Precipitation should be on the dry side for northern and western portions of Nebraska. However, there could be above average precipitation in the southeastern section of the state," Hu said.
His analysis also indicates the dry summers Nebraska has experienced in recent years should continue, possibly for the next five to seven years. Fall and winter precipitation patterns in the next few years also should be drier, he said.
"Not all those years and not all seasons in each year of the next five to seven years will be dry. There will be wet years, but a majority of those years will be on the dry side," Hu said.
Hu said he has a high degree of confidence in his predictions. They are based on advanced analysis of historical precipitation data collected at weather stations statewide and from Kansas, Missouri, Illinois, Iowa, Colorado and Wyoming. These states' weather patterns can strongly influence what happens in Nebraska and help support and amplify the historical data that Hu analyzes.
"Sophisticated data analyses and computer modeling greatly improves the accuracy of predicting weather trends and anomaly patterns. I think it's one of the best methods to predict local rainfall and I give it a confidence rating of better than 70 percent," Hu said.
His statistical analyses indicate that precipitation patterns follow 18- to 23-year cycles. This pattern accurately reflects Nebraska's intensive drought periods during the 1930s, 1950s and late 1970s. This pattern shows a 10-year wet period ending in the late 1990s, followed by the current extended dry pattern.
"Those extended patterns form from an overall trend that can be examined on a year-to-year basis," Hu said, explaining that not all years in the extended dry period will be dry.
"We will have some periods of wet weather within the current (dry) pattern ... but overall, in the dry phase of the cycle, precipitation will be below normal," he said.
Hu said information from his analysis should be useful to all Nebraskans, especially agricultural producers. He hopes they'll use it to plan what type of crops to plant, plant density, tillage methods, as well as crop insurance to minimize impacts of the dry conditions.
More information on Hu's analysis is available at the Precipitation and Temperature Predictions for Nebraska Web site.
Hu's research is conducted in cooperation with IANR's Agricultural Research Division and funded in part by the U.S. Geological Survey Global Change Program.
09/26/02-SR
Steve Ress UNL Water Center - Communications Coordinator (402) 472-3305
Department: School of Natural Resource Sciences
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