Atlantic application of the Systematic Approach to Tropical Cyclone Track Forecasting. Part I environmental structure characteristics

Abstract

This Meteorological knowledge base for application of the Systematic Approach to Tropical Cyclone Track Forecasting in the Atlantic basin follows from similar knowledge bases previously developed for the western North Pacific, the eastern and central North Pacific, and the Southern Hemisphere. A common environment structure terminology has been adopted in which three synoptic patterns (Standard, Poleward, and Midlatitude) are found in each of these basins. Each basin also has a special pattern, which in the Atlantic is the Upper-level low. The conceptual models for these synoptic patterns with their associated synoptic regions are described here via a conceptual model, analysis examples, and the characteristic track segments within each region. A climatology of occurrences in each patter/region for the 1568 cases during 1990- 98 is prepared. The second key element in the knowledge base is the transitional mechanisms that change the environment structure and thus change the tropical cyclone steering flow. Conceptual models for these mechanisms are presented and illustrated with sequences of analyses. A climatology of recurring (at least four occurrences in nine years) transitions is prepared to indicate the most common track changes during these transitions.