Diagnosing Track and Intensity of Landfalling Tropical Cyclones using VORTRAC 2.0

Vortex Objective Radar Tracking and Circulation (VORTRAC) integrates a series of algorithms to deduce the central pressure and radius of maximum wind (RMW) of a landfalling TC in near real time from WSR-88D Level II radar data and environmental reference pressure data from nearby coastal weather stations. VORTRAC 1.0 was officially accepted for operation at the National Hurricane Center (NHC) in 2008. In its previous operational form, VORTRAC 1.0 required external scripts to fetch input data and user input of an initial TC position, RMW estimate, and radar selection. This mode of operation made the software challenging to use. Several improvements to the software robustness and usability have subsequently been made in VORTRAC 2.0.

The purpose of this paper is to present an improved VORTRAC 2.0 that can automatically diagnose central surface pressure and its tendency from radar-derived wind fields at NHC as additional guidance for TC intensity change near landfall when a TC center is within the Doppler range of a coastal WSR-88D. We will demonstrate VORTRAC 2.0 capabilities using examples from 13 historical landfalling TCs from 2005-2011.