Objective Updraft Tracking in Mesoscale Models – Dynamical Properties of Hurricane Rainband Convection

An objective updraft tracking algorithm (Statistical and Programmable Objective Updraft Tracker - SPOUT; Terwey and Rozoff, 2014) is used to study the dynamical properties and morphology of rainband convection in two mesoscale hurricane simulations. SPOUT tracks updrafts by assuming vertical continuity of vertical velocity, rather than focusing on microphysical properties (as in radar applications). This extensible and objective approach allows users to track and examine the properties of individual updrafts as they form and evolve in model simulations (e.g. Terwey and Rozoff, 2014).

In this work, we use the algorithm on two hurricane simulations: a 2-km horizontal resolution RAMS simulation and a 1-km horizontal resolution WRF simulation. By collecting data in and around these updrafts, we perform basic statistical analyses to determine spatial and temporal trends in the convective dynamics through an updraft's lifecycle, including local helicity changes, local shear changes and local pressure perturbation morphology.

A beta of SPOUT's Python code has been released publicly (https://github.com/wterwey/SPOUT) and will continue to be cleaned up and worked through in the coming years.