Snapshot of tropical cyclones visualized by column integrated water vapor from AM2.5C360 simulation. Created by Wenchang Yang. Tropical cyclones (TCs) are a major natural hazard to life and property. Yet it remains a big challenge to project and understand how TCs, particularly in terms of frequency, will respond to climate change with the traditional TC genesis theory. To address this issue, we develop a two-stage seed-probability framework in which variability of seeds is highlighted. By conducting a suite of numerical experiments using TC-permitting high-resolution climate models, we demonstrate that this framework is a useful tool to help understand TC frequency variability and response to climate forcings. Related publications: Hsieh, T.-L., Yang, W., Vecchi, G. A., & Zhao, M. (2022). Model spread in the tropical cyclone frequency and seed propensity index across global warming and ENSO-like perturbations. Geophysical Research Letters, 49, e2021GL097157. doi: 10.1029/2021GL097157 Yang, W., T.-L. Hsieh, and G. A. Vecchi, 2021: Hurricane annual cycle controlled by both seeds and genesis probability. Proc. Natl. Acad. Sci. USA, 118, e2108397118, doi: 10.1073/pnas.2108397118. Zhang, B., Soden, B. J., Vecchi, G. A., & Yang, W. (2021). The Role of Radiative Interactions in Tropical Cyclone Development under Realistic Boundary Conditions, Journal of Climate, 34(6), 2079-2091. doi: 10.1175/JCLI-D-20-0574.1 Hsieh, TL., Vecchi, G.A., Yang, W. et al. Large-scale control on the frequency of tropical cyclones and seeds: a consistent relationship across a hierarchy of global atmospheric models. Clim Dyn 55, 3177–3196 (2020). doi: 10.1007/s00382-020-05446-5 Yang, W., Vecchi, G., Fueglistaler, S., Horowitz, L. W., Luet, D. J., Muñoz, Á. G., et al. ( 2019). Climate impacts from large volcanic eruptions in a high‐resolution climate model: The importance of forcing structure. Geophysical Research Letters, 46, 7690– 7699. doi: 10.1029/2019GL082367 Vecchi, G.A., Delworth, T.L., Murakami, H. et al. (2019). Tropical cyclone sensitivities to CO2 doubling: roles of atmospheric resolution, synoptic variability and background climate changes. Climate Dynamics doi: 10.1007/s00382-019-04913-y Bhatia, K.T.,G. A. Vecchi, T. R. Knutson, H. Murakami, J. Kossin, K.W. Dixon and C.E. Whitlock. (2019) Recent increases in tropical cyclone intensification rates. Nature Communications 10 (1) article number: 635. doi: 10.1038/s41467-019-08471-z