Accession Number : ADA114150

Title :   Statistical Post-Processing of the Navy Nested Tropical Cyclone Model and the Operational Tropical Cyclone Model.

Descriptive Note : Final rept. Oct 80-Sep 81,


Personal Author(s) : Peak,James E ; Elsberry,Russell L

PDF Url : ADA114150

Report Date : Sep 1981

Pagination or Media Count : 55

Abstract : A statistical technique proposed by Elsberry and Frill (1980) for adjusting dynamical tropical cyclone motion forecasts is extended to the Two-Way Interactive Nested Tropical Cyclone Model (NTCM) and the operational One-Way Interactive Tropical Cyclone Model (TCMO). The technique utilizes linear regression equations to reduce systemic errors. Backward extrapolation positions are presented as a less expensive, but inferior, alternative to the backward integration positions required by the original technique. A scheme is developed for applying the technique in storm-motion coordinates as well as zonal-meridional coordinates. Tests with 186 NTCM cases indicate moderate improvement in forecast errors by the zonal-meridional regression technique, and slight improvement by the storm-coordinate scheme. In TCMO tests with 212 cases, the zonal-meridional regression equations reduced the forecast errors, but the storm-coordinate equations did not. The technique failed to improve forecast errors in independent tests with NTCM 1981 data, presumably due to differences in error biases, which indicates a need for a larger sample size. Alternatively backward integration positions may be necessary to achieve consistent improvements from this statistical technique. The technique was able to improve 60h-72h forecast errors in TCMO 1981 cases. (Author)

Descriptors :   *Tropical cyclones, *Weather forecasting, Motion, Tracks, Predictions, Errors, Bias, Linear regression analysis

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE