biostudies-literatureUnknown14(1)Feng XUnderstanding and prediction of tropical cyclone (TC) activity on the medium range remains challenging. Here, we find that the pre-existing westward-moving equatorial waves can inform the risk of TC occurrence and intensification, based on a dataset obtained by synchronising objectively identified TCs and equatorial waves in a climate reanalysis. Globally, westward-moving equatorial waves can be precursors to 60-70% of pre-tropical cyclogenesis events, and to >80% of the events with the strongest vorticity, related to the favourable environmental conditions within the pouch of equatorial waves. We further find that when storms are in-phase with westward-moving equatorial waves, the intensification rate of TCs is augmented, whilst in other phases of the waves, storm intensity grows more sloNature communications511https://www.ebi.ac.uk/biostudies/studies/S-EPMC9889306biostudies-literatureEquatorial waves as useful precursors to tropical cyclone occurrence and intensification.PMC9889306Feng XMethven JHodges KIYang GYfalseEquatorial waves as useful precursors to tropical cyclone occurrence and intensification.Understanding and prediction of tropical cyclone (TC) activity on the medium range remains challenging. Here, we find that the pre-existing westward-moving equatorial waves can inform the risk of TC occurrence and intensification, based on a dataset obtained by synchronising objectively identified TCs and equatorial waves in a climate reanalysis. Globally, westward-moving equatorial waves can be precursors to 60-70% of pre-tropical cyclogenesis events, and to >80% of the events with the strongest vorticity, related to the favourable environmental conditions within the pouch of equatorial waves. We further find that when storms are in-phase with westward-moving equatorial waves, the intensification rate of TCs is augmented, whilst in other phases of the waves, storm intensity grows more slo2023-01-01T00:00:00Z2023 Jan2025-04-06T19:14:50.678Z2025-04-06T19:14:50.678ZS-EPMC98893063672087610.1038/s41467-023-36055-5