Climatological analysis of tropical cyclone intensity changes under moderate vertical wind shear

A potential hypothesis is that other factors-associated with both the TC and its environment-can help offset the effects of VWS and aid intensification. This hypothesis was tested with a large dataset of 6-hourly best tracks and environmental diagnostics for global TCs between 1982 and 2014.

Moderate VWS was objectively defined as 4.5-11.0 ms(-1), which represents the 25th-75th percentiles of the global distribution of 200-850-hPa VWS magnitude around TCs. Intensifying events (i.e., unique 6-hourly data points) were compared against steady-state events to determine which TC and environmental characteristics favored intensification under moderate VWS. This comparison showed that intensifying events were significantly stronger, closer to the equator, larger, and moving with a more westward motion than steady-state events.