Seasonal Predictions of Tropical Cyclones Using a 25-km-Resolution General Circulation Model

• DOI: 10.1175/jcli-d-12-00061.1
• Publication Date: 2012-07-13T23:32:35Z
• Authors: Jan-Huey Chen; Shian-Jiann Lin
• Keywords: Atlantic hurricane; Anomaly (physics); Atmospheric Circulation; Tropical Atlantic; Atmospheric models

Abstract Retrospective seasonal predictions of tropical cyclones (TCs) in the three major ocean basins Northern Hemisphere are performed from 1990 to 2010 using Geophysical Fluid Dynamics Laboratory High-Resolution Atmospheric Model (HiRAM) at 25-km resolution. states initialized for each forecast, with sea surface temperature anomaly (SSTA) “persisted” that starting time during 5-month forecast period (July–November). Using a five-member ensemble, it is shown storm counts both (TS) and hurricane categories highly predictable North Atlantic basin 21-yr period. The correlations between observed model predicted 0.88 0.89 hurricanes TSs, respectively. prediction eastern Pacific skillful, but not as outstanding Atlantic. persistent SSTA assumption appears be less robust western Pacific, contributing skillful region. relative skill consistent quality large-scale environment basins. It intensity distribution TCs can captured well by if central level pressure used threshold variable instead commonly 10-m wind speed. This demonstrates feasibility 25-km-resolution HiRAM, general circulation designed initially long-term climate simulations, study impacts change on TCs.