Evaluation of the Extrapolation Feature of the TYFOON Analog Computer Program.

摘要

The original version of the TYFOON analog program, first used operationally by FLEWEACEN/JTWC Guam in 1970, has been modified several times to improve its performance. The version used during the 1973 season was known as TYFOON-72. Addition of the 1970 and 1971 tropical cyclone data to the analog data tape plus extension of the storm tracks to the 'bitter end' suggested further modifications to the analog program. Elimination of the extrapolation feature plus reduction of the time envelope resulted in the latest version, TYFN73. A test was conducted, using 1972 data, to determine if the changes incorporated into TYFN73 degraded the forecast positions generated by the analog program. The results of this test revealed no significant differences in forecasting accuracy between TYFOON-72 and TYFN73. In addition, TYFN73 ran over 46 percent faster. As a result, TYFN73 will be used operationally during the 1974 tropical cyclone season. (Author)