Could region be in for harsher weather for next few years?

The cold and snowy winter this season might be attributed to a change in temperature of the Pacific Ocean, said John Wheeler, meteorologist for Forum Communications Co. If that proves true the northern Plains could see several years of harsher weather in the future.

“2008 was the coldest year since 1996,” Wheeler said. “That is a break in a trend of much above average weather and might be attributed to a shift in weather patterns involving sea surface temperatures in the Pacific.”

The Pacific Decadal Oscillation was discovered by fisheries scientists studying cycles in salmon populations in the late 1990s. They found surface temperatures of the eastern Pacific Ocean vary on about a 30-year cycle not only affecting fish populations but the weather inland. By studying historic records they have been able to establish a record of the phenomenon back to the 1880s.

“The sea temperature in the eastern part of the Pacific has been in a warm phase since 1980,” said Dr. Steve Hu, associate professor at the School of Natural Resources and a staff member of the High Plains Regional Climate Center both located at the University of Nebraska, Lincoln. “But it is now showing signs of reverting to the cold phase. The previous cold phase was from 1948 to 1979, the stormy years of the 1960s were in the cold phase.”

But Hu said the situation is more complex than just anticipating cold and stormy winters for the next three decades.

“The PDO controls about 30 percent of the weather factors for the northern Plains,” he said. “The warm phase weakens the El Nino and La Nina effects. The next 30 years the cold phase will intensify those effects.”

El Nino and La Nina are Pacific Ocean currents near the equator that have an impact on the weather conditions of North America on an approximately 18-month cycle. According to the Web site of the National Oceanic and Atmospheric Administration, La Nina means wetter and colder winters in the northern part of the United States. El Nino weather tends to bring wetter weather to the south and drier winter conditions to the northern United States.

The region is currently under the influence of a developing La Nina, according to the Web site of the National Weather Service Climate Prediction Center.

Hu said while the warm PDO seen for the last 30 years has played a part in warmer average temperatures seen in parts of the United States over the past decades it can’t be seen as the sole cause of the statistics often used to argue the existence of global warming.

“Global warming is on a global scale,” Hu said. “PDO is a minor thing in the total system of worldwide climate.”

Sun reporter Keith Norman can be reached at (701) 952-8452 or by e-mail at knorman@jamestownsun.com

Tags: winter, weather, cold, news, pdo, pacific, ocean