Published: July 16, 2002

Tim Palmer of the European Centre for Medium Range Weather Forecasts in England will address the value of ensemble forecast techniques in a free talk on Friday, July 19, at the University of Colorado at Boulder.

Palmer's talk, "Predicting Weather and Climate: A Risky Business," will give examples of ensemble forecasting techniques and demonstrate their applications in crisis weather events such as flooding.

Palmer's talk is sponsored by the Cooperative Institute for Research in Environmental Sciences and will be at 10 a.m. in the CIRES Auditorium, room 338 of the CIRES Building on the CU-Boulder campus. The talk is part of the Distinguished Lecture Series program sponsored by CIRES.

Head of the Predictability and Seasonal Forecast Division of the European Centre for Medium-range Weather Forecasts, Palmer was the lead author of the 2001 Third Assessment report of the Intergovernmental Panel on Climate Change, and coordinator of a major European Union multinational project on the prediction of El Niño and other seasonal climate anomalies.

Ensemble weather forecasting has been used since about 1992 in the United States and Europe. The technique involves using computers to generate multiple weather forecasts, rather than a single deterministic forecast. Multiple forecasts are useful for estimating weather and climate risks, as well as forecast uncertainties.

"It's no longer enough to forecast the likely future weather," Palmer said. "Increasingly, the public, disaster relief agencies and commercial forecast users need to know the changing risk of extreme weather events which on a day-to-day basis may be unlikely to occur, but have grave consequences on people's livelihoods when they do occur."

For information call (303) 735-0196.