On the Mechanisms of the Active 2018 Tropical Cyclone Season in the North Pacific

Friday, Nov 8, 2019

The 2018 tropical cyclone (TC) season in the North Pacific was very active, with 39 tropical storms including 8 typhoons/hurricanes. Unlike the typical limitations in skill of seasonal predictions made before April initial forecasts, the active 2018 TC season was successfully predicted by the Geophysical Fluid Dynamic Laboratory Forecast-oriented Low Ocean Resolution (FLOR) global coupled model 3–5 months in advance (i.e., successful predictions from 1 February 2018).

The authors of a paper, recently published in Geophysical Research Letters and led by Yitian Qian, an AOS visiting student research collaborator, used a suite of idealized experiments with three dynamical global models to show that the active 2018 TC season was primarily caused by warming in the subtropical Pacific associated with the positive phase of the Pacific Meridional Mode, and secondarily by warming in the tropical Pacific associated with Central Pacific El Niño.  Former AOS Associate Research Scholar Hiroyuki Murakami (UCAR), AOS Faculty Member Tom Delworth, Former AOS Postdoc Sarah Kapnick '04 (GFDL), and GFDL V. Ramaswamy are among the paper's co-authors.

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