A preliminary assessment of the Polar Ice Prediction System

The National Ice Center relies upon a coupled ocean/ice model called the Polar Ice Prediction System (PIPS) to provide guidance for its 1-7 day sea ice forecasts. Here we present results on the forecast skill of this system for the highly variable month of May 2000. In this study we use a "threat index" patterned after methodologies used for tornado forecasting to assess changes in ice concentration. Specifically, the question was asked: does PIPS correctly forecast ice-free (C<15%) and ice-covered (C>15%) regions? SSMA satellite data and other remotely sensed products are used to establish the skill score. In contrast to persistence, which has a skill of only 40-50%, it was found that PIPS correctly forecasts these situations /spl sim/90% of the time.