P2.3
Examination of the skill produced by a natural analog ensemble system and its potential extension to solving the middle latitude 2-4 week forecast problem
PAPER WITHDRAWN
Jeremy D. Ross, Penn State University, University Park, PA; and R. Hart, J. M. Fritsch, C. Hosler, R. H. Grumm, and R. James
Examination of the natural analog ensemble system's skill within the 53-yr period of verification reveals interim periods wherein the analog system is substantially better than climatology and persistence. Of particular significance is that the analog system is capable of predicting the onset, evolution, and end of major thickness anomalies even when the initial conditions are near climatology. For example, the analog system forecasts both the formation and decay of the major 1982-1983 thickness anomaly (associated with El Nino) when starting from early-mid 1982 initial conditions, i.e., 5-12 months prior to the onset and end, respectively, of the El Nino event. The forecasting system provided similar 5-12 month lead times on the formation and decay of major thickness anomalies for the 1987, 1990 and 1998 El Nino events. Moreover, the system exhibited periods of considerable forecast skill during neutral ENSO events (e.g., 1979-1980), suggesting that the analog method is successful at anticipating significant tropical thickness anomalies other than those driven by ENSO. The same fundamental methodology, with a tuning of essential analog matching parameters, was used to produce natural analog forecasts for the middle latitudes of 2-4 weeks in length. Preliminary results will be presented.
Poster Session 2, Seasonal to interannual climate prediction with emphasis on the 2002 El Nino (Hall 4AB)
Thursday, 15 January 2004, 9:45 AM-9:45 AM, Hall 4AB
Previous paper Next paper