Summary of Seasonal Outlooks

(released August 19, 2010)

 

Climate Prediction Center (CPC) 30 and 90-day Outlooks
30-Day Temperature Outlook
30-Day Precipitation Outlook
90-Day Temperature Outlook 90-Day Precipitation Outlook



(click on images to enlarge)

 Regional Temperature Summary:

  • No strong forecast trends are noted in the 30-day outlook period, and there are equal chances (33% each) of above, below and near normal temperatures across the Plains region. Above normal temperatures are expected to the east and west of the Central Plains.
  • The 90-day outlook period depicts a large area of higher than normal probabilities for above average temperatures from the Desert Southwest across the Central Plains and into the Great Lakes and New England states. The greatest likelihood for above normal temperatures is in the southwest United States, where there is a greater than 50% chance of warmer than normal temperatures for the September-November period. 
  • Check out the 30-day outlook discussion and the 90-day outlook discussion.

Regional precipitation summary:

  • During the 30-day outlook period (September), there are equal chances (33%) above, below or normal precipitation from the Dakotas through northern Texas. There is a greater than 40% probability of conditions being drier than normal across Colorado and into the Great Basin. The drier than normal outlook corresponds to warmer than normal temperatures and the development of La Nina conditions.  Above normal precipitation is expected along the Gulf Coast and Southeast United States with the likelihood of an active hurricane period during September.
  • An outlook for above normal precipitation enters the 90-day outlook (September-October-November), and is centered on the Nebraska Sandhills. The region extends out with a 400 to 700 mile radius, and covers most of the Dakotas and Nebraska. Probabilities are greater than 40 percent from northeast Colorado to central South Dakota for above normal precipitation. Southwest Colorado will have a greater than 33 percent chance of below normal precipitation.
  • The higher probability of precipitation in the Central and Northern Plains is attributed to decadal trends and is consistent with the developing La Nina (according to CPC).

 

Drought Information
"Western" Central Region Drought Monitor "Eastern" Central Region Drought Monitor Latest Seasonal Drought Outlook
  (click on images to enlarge)  

Regional Drought Summary:

  • The U.S. Drought Monitor depicts small pockets of abnormally dry and drought conditions in the central United States. Severe drought (D2) is currently observed in the Upper Peninsula of Michigan, extreme northern Wisconsin and the Arrowhead of Minnesota. Moderate drought (D1) surrounds this area, and extends into the northern part of Lower Michigan. A small area of moderate drought is ongoing in southeast Missouri, western Kentucky and in parts of western Wyoming. Abnormally dry conditions were added to parts of southeast Nebraska, northeast Kansas and far northern South Dakota.
  • The latest Seasonal Drought Outlook (released August 19) expects drought conditions to improve some in the northern Great Lakes. Drought conditions are expected to persist in western Wyoming and southeast Missouri and Kentucky. 

 

El Nino/Southern Oscillation Information:

  • "La Nina conditions are expected to strengthen and last through the Northern Hemisphere winter of 2010-11." - CPC
  • "Temperature and precipitation impacts over the United States are typically weak during the Northern Hemispheric summer and early fall, but strengthen considerably during the late fall and winter." - CPC

    

ENSO Alert Status: La Nina Watch

ENSO Diagnostic Discussion (PDF)

Weekly ENSO Diagnostic Briefing (PDF)

   (CPC graphics below)
                             
 
                                                        

International Research Institute (IRI) for Climate and Society

(IRI graphics below)

 
 Above: CPC Consolidated SST forecast for the Nino 3.4 region (fall and winter months indicate La Nina conditions).   Above: Model predictions of SST anomalies for the Nino 3.4 region.

 
 
 
Above: Equatorial ocean temperature anomalies at various regions in the central Pacific Ocean (blue areas correspond to cooler than normal).   Above: Probabilistic ENSO forecast for the Nino 3.4 region.

 

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