Fig. 4. Relative probability of the translation speed of tropical cyclones (TCs) that pass through an area within 300 km from Houston.

a Total speed; b Meridional speed v; c Zonal speed u. Data from observations (1981–2018, gray), and from the HIST (1981–2005; blue) and RCP8.5 (2071–2099; red) Columbia TC HAZard-Coupled Model Intercomparison Project 5 (CHAZ-CMIP5) downscaling simulations. The observational data are from International Best Track Archive for Climate Stewardship, version 4. The black vertical lines in gray bars show one standard deviation from observations while the symbols along the blue and red bars show the mean values from individual CMIP5 models. See Methods for further details. In a, there is ~10% shift from the relative probability of slow-moving TCs toward that of fast-moving TCs under RCP8.5 (see text). In b, there is ~9.8% shift from the relative probability of slow-moving TCs (|v| ≤ 5 km h⁻¹) toward that of fast-moving TCs (northward speed v ≥15 km h⁻¹) under RCP8.5. In c, there is ~2.9% shift from the relative probability of slow-moving TCs (|u| ≤5 km h⁻¹) toward that of fast-moving TCs (westward speed u ≥15 km h⁻¹). Supplementary Fig. 17 shows the same analysis but with bias correction.