Colorado State Hurricane Forecast Team Calls for an Active September

Note to Editors: This forecast contains an individual prediction for September hurricane activity. It should not be considered a new seasonal forecast. William Gray and Phil Klotzbach are available for interviews regarding this forecast after 8:30 a.m. MDT.

Well above-average hurricane activity is expected for the month of September, the Colorado State University forecast team said today.

The individual month of September is expected to experience five named storms. The CSU team calls for four of the five storms to become hurricanes and two to become major (Category 3-4-5) hurricanes. Overall, the forecast team expects activity at about 190 percent of the September average.

"We expect the month of September to be quite active," said Phil Klotzbach, lead author of the hurricane forecast. "We have seen some of the lowest pressure readings on record in the tropical Atlantic during August. Water temperatures in the tropical Atlantic remain at above-average values. A combination of these two factors typically leads to an active September.  In addition, we continue to observe neutral ENSO conditions in the tropical Pacific, so we do not expect that ENSO will be detrimental to September’s activity."

"We predict that September will be quite active based on climate signals through August," said William Gray, who has been issuing hurricane forecasts at Colorado State for 25 years.

June and July were very active with three named storms forming during the two-month period (Bertha, Cristobal and Dolly).  Bertha became the longest-lived July storm on record, while Hurricane Dolly made landfall in south Texas as a Category 2 hurricane.

August had slightly above-average activity due largely to Hurricane Gustav which became a major hurricane in the northwest Caribbean last week.  

The Colorado State team continuously works to improve forecast methodologies based on a variety of climate-related global and regional predictors.

For a detailed description of the many detailed forecast factors, visit the Web at

The team will issue a prediction for October 2008 Atlantic basin hurricane activity on Oct. 1.