Prototype Expert System to Forecast Severe Winds in the Western Mediterranean Sea.

摘要

A prototype expert system is designed to forecast severe winds in the western Mediterranean Sea. The first version of the expert system is to nowcast levante conditions in the Strait of Gibraltar and to nowcast/forecast mistral conditions in the Gulf of Lion. Rules of thumb for these events from the Handbook for Forecasters in the Mediterranean (Brody and Nestor 1980) are tested with observations during the period September 1988 through February 1989. Of the 19 rules listed in the Handbook for levante, five are used in the expert system without modification, six are modified and eight are discarded. Of the 41 rules for the mistral, 14 are used without modification, two are slightly modified and 25 are eliminated. The first step in each case is to select adjacent land stations whose observations best infer the presence of the gale wind conditions over the open seas, where in situ observations are not available. The basic approach in the expert system is to provide an ordered sequence of rules (based on the verifications during the six-month period) that the forecaster can continue to test until a forecast decision can be made with confidence. Operational testing is needed to refine the severe wind algorithm, which can be easily modified to include more empirical rules from forecasters in the future. Keywords: Levante forecasting, Mistral forecasting, Theses. (sdw)