The Dynamical Tropopause Location as a Potential Predictor for North Atlantic Tropical Cyclone Activity

Abstract Tropical cyclones are among the most devastating natural phenomena that can cause severe damage when undergoing landfall. In wake of poorly forecast 2013 North Atlantic hurricane season, Rossby wave breaking on 350-K isentropic surface has been linked to tropical cyclone activity measured by accumulated energy (ACE). Here, ERA5 data and HURDAT2 used argue latitude 2 potential vorticity unit (PVU; 1 PVU = 10 −6 K kg −1 m s ) contour 360-K in western is changes vertical wind shear relative humidity during month September. A more equatorward position 2-PVU shown be an increase a reduction humidity, as manifested increased ventilation index, The further number named storms, storm days, lifetime, making Changes genesis location importance for landfall frequency lifetime. summary, can, therefore, potentially predictor seasonal subseasonal forecasting. Significance Statement Forecasts season operationally produced. Their aim predict their total throughout season. This study proposes include tropopause these forecasts, it midtropospheric Atlantic. thereby cyclones, link particularly strong