Fig. 5: IPT-related environmental conditions for TC genesis.

Regressions on the inverse IPT for (A) vertical wind shear (m s−1), (B) 850-hPa relative vorticity (10−6 s−1), (C) 500-hPa meridional gradient of zonal wind (10−6 s−1), (D) 500-hPa vertical velocity (10−2 Pa s−1), (E) dynamic genesis potential index (shading) and genesis density (contour, interval of 0.02 yr−1), and (F) 700-hPa relative humidity (%). Stippling indicates that regression is significant at the 0.05 significance level.