Characteristics of the early stages of tropical cyclones as viewed with microwave data

This paper identifies several characteristic signatures and signs of potential future intensification as viewed with satellite-based microwave data during the initial stages of tropical cyclones (TC) development. During the past several years, new techniques to integrate more conventional infrared and visual satellite imagery with special polar-orbiting microwave imagery and scatterometer backscatter data have shown great promise toward better revealing identifiable characteristics in convective structure and surface features that were previously difficult to identify. This is particularly true for the pre-disturbance and pre-intensification stage TC where post analysis often shows that initial satellite-based analyses are typically ‘low' and ‘slow'. Earlier studies have shown the advantage of how adding polar orbiting microwave data, integrated with the more frequent geostationary visual and infrared imagery, can provide considerably better accuracy in the low-level center position. This study reveals that there is considerable knowledge to be gained by looking at the changes in the convective and low-level cumulus structure that were previously obscured by higher-level clouds. These recognizable features have the potential to provide more accurate and earlier timing of initial warnings and greater insight, when considered with other environmental factors, into the potential for a TC to undergo rapid intensification versus slow to average intensification.