Climatology and Predictability of Atmospheric Rivers in the GFDL FLOR Model

Some of the heaviest precipitation events over the western United States and the United Kingdom are caused by storms known as atmospheric rivers (ARs). Like hurricanes, ARs are long-lived and originate in the tropics before moving poleward until they make landfall. These moisture-laden storms produce significant precipitation over a few days, which can cause potentially devastating flooding. Despite their destructive power, these storms are also an important component of regional water supply. The positive and negative societal influences of ARs make sound scientific predictions of these storms of great value. We assess the climatology and predictability of these storms globally using the GFDL FLOR coupled model. This high-resolution global model has 50 km resolution in the atmosphere and land surface. Two experiments have been conducted: (1) control simulation with prescribed 1990 radiative forcing and land-use conditions and (2) annual forecast simulations from 1981-2013 that are initialized monthly.