Examining Trends in Satellite-Detected Overshooting Tops as a Potential Predictor of Tropical Cyclone Genesis

A geostationary satellite-derived cloud product based on an overshooting top (OT) detection algorithm is utilized to identify OT activity associated with Atlantic tropical disturbances. Detected OTs can serve as a proxy for vortical hot towers, which have been linked to tropical cyclone (TC) genesis. The forecast skill potential is explored by examining thresholds of OT activity and trends.

The OT algorithm is examined as a predictor both on its own and in a multi-parameter genesis forecast scheme. TC genesis forecast skill is explored by examining OT activity and trends within selected radii and annuluses of a developing TC centers prior to genesis. An analysis of cases from 2010 to 2015 reveals an empirically-based scheme is skillful at predicting if a potential disturbance will develop into at least a tropical depression at some point in the future (yes/no). Predicting when (lead time) a disturbance will develop into at least a tropical depression is also investigated. OTs are also compared to a multi-parameter genesis forecast to analyze significance of OTs compared to other parameters and analyze OTs impact on TC genesis forecasts.