Subseasonal controls of U.S. landfalling tropical cyclones

Abstract Landfalling tropical cyclones (LTCs) are the most devastating disaster to affect U.S., while demonstration of skillful subseasonal (between 10 days and one season) prediction LTCs is less promising. Understanding mechanisms governing variation TC activity fundamental improving its forecast, which critical interest decision-makers insurance industry. This work reveals three localized atmospheric circulation modes with significant 10–30 variations: Piedmont Oscillation (PO), Great America Dipole (GAD), Subtropical High ridge (SHR) modes. These strongly modulate precipitation, genesis, intensity, track, landfall near U.S. coast. Compared their strong negative phases, East Coast has 19 times more during positive phases PO, Gulf experiences 4–12 frequent GAD SHR. Results from GFDL SPEAR model show a 13, 9, 22 for these modes, respectively. Our findings expected benefit on weather timescale also suggest opportunities exist predictions associated heavy rainfalls.