8-21-09 Climate Update

8-21-09 Climate Update

30 day forecast 30-day temperature forecast
The Climate Prediction Center's 30-day outlook shows Nebraska having equal chances of above normal, normal, or below normal temperatures in September. The Climate Prediction Center's 30-day outlook shows Nebraska having equal chances of above normal, normal, or below normal precipitation in September.

 

90-day temperature forecast
The Climate Prediction Center's 90-day outlook shows Nebraska having equal chances of above normal, normal, or below normal temperatures in September.
90-day precipitation forecast
The Climate Prediction Center's 90-day outlook shows Nebraska with above normal chances for precipitation in western Nebraska and equal chances of above normal, normal, or below normal precipitation for the eastern half of the state in September.

August 21, 2009

The 30-day forecast issued for September by the Climate Prediction Center indicates equal chances for above normal, normal, or below normal temperatures and precipitation. The 90-day forecast for September through November indicates a tendency toward above normal moisture for the western half of Nebraska and equal chances of above normal, normal, or below normal precipitation for eastern Nebraska. The 90-day forecast for temperature projectss equal chances in all three categories for the entire state.

Looking at conditions in past years when La Nina transitioned to El Nino, some distinct trends materialize. The strongest trends occur across the western third of Nebraska, with precipitation consistently running below normal during the October through February period. October temperatures were consistently above normal. The remaining months from September through April had no dominant trend. If we have a similar below normal precipitation trend, then snowpack feeding the Platte River basin is likely to below normal heading into the 2010 runoff season.

In these years the central third of the state experienced below normal September temperatures and above normal October temperatures. Precipitation was above normal during September and February, with below normal conditions during the November through January period. The remaining months indicated no defined precipitation or temperature trend.

The eastern third of the state had a below normal temperature trend during the November through December period, with an above normal trend in February. November and March had below normal precipitation trends, while January and April had above normal precipitation. No trend was found for temperatures and precipitation in the remaining months.

Al Dutcher
State Climatologist