Moisture sources for precipitation associated with major hurricanes during 2017 in the North Atlantic Basin

Abstract

The 2017 North Atlantic tropical cyclone season was among the most active in the last two decades, with 17 named storms, of which six reached the major hurricane (MH) intensity: Harvey, Irma, Jose, Lee, Maria, and Ophelia. In this study, the water vapor sources for precipitation for these six MHs were examined using a Lagrangian approach. The particle dispersion model, FLEXPART, was used to identify moisture sources. Overall, the North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico were identified as the main moisture sources, supplying ∼75%–85% of the atmospheric humidity gained by tropical cyclones, which resulted in precipitation associated with the MHs. However, the South Atlantic Ocean also contributed considerable humidity (∼14%–20%), and the remaining ∼1%–5% originated from the tropical eastern Pacific Ocean. The accumulated moisture uptake higher than the 90th percentile generally appeared within approximately 3° to 5° of the TC trajectory.