Improvements in integrated satellite reconnaissance tropical cyclone fix accuracy

This paper presents several case studies and some seasonal averages showing how a new integrated satellite reconnaissance tropical cyclone (TC) positioning technique using both satellite-based microwave data and the more conventional infrared and visual satellite imagery greatly improves overall TC fix accuracy. Many cases were taken from a lateral study in this conference where fix positions from several forecast agencies were compared and found to have large differences in both positioning and intensity estimates. These cases typically occurred during two stages of development in the TC's life cycle. The first set of cases often occurred in the TC early stage of development when thick, less organized cloud cover obscured the surface features used in the visual and infrared techniques and when continuity in either movement or structure (in the case of shear) had yet to be determined. The second set typically occurred during the final extratropical transition stage when the upper-level cloud features often separated from the still obscured low-level center. This technique uses some of the methods that were presented in earlier presentations using a combination of polar-orbiting scatterometer wind, ambiguity, and radar cross-section data, microwave 85 and 37 GHz imagery and the more frequent geostationary infrared and visual imagery. One important topic that is addressed is how to integrate the more frequent geostationary imagery and the requirement to meet a ‘fix' time with that of using a less frequent but typically more accurate polar orbiting image.