Atlantic tropical cyclones (TCs) can cause significant damage and impact both societal and economic sectors. According to the National Hurricane Center, Hurricane Katrina of 2005 devastated the shores of New Orleans and was responsible for at least $108 billion of property damage. Decades of effort to further understand and predict Atlantic TC activity have improved seasonal forecast skill; however, there are still large uncertainties due to an incomplete understanding of the atmospheric drivers of TC variability.
In a new Geophysical Research Letter Journal, authors Wei Zhang, Gabriele Villarini, and Gabriel A. Vecchi, find an association between the East Asian Subtropical Jet Stream (EASJ) and the frequency of Atlantic TCs (wind speed ≥ 34 knot) during July-October and hurricanes (wind speed ≥ 64 knot) during August-November based on observations for 1980-2018.
This strong association is tied to the impacts of EASJ on the propagation of Rossby wave trains from East Asia to the North Atlantic, leading to changes in vertical wind shear over the Atlantic Main Development Region (MDR). The authors note these findings suggest a potential predictor for the frequency of Atlantic TCs and hurricanes and a new aspect that could improve the simulation of these storms with climate models. Furthermore, decadal changes in EASJ may be an influence into Atlantic TC activity in the future,highlighting the need to assess the extent that the climate models can capture the mean state, seasonal variations and forced changes of the EASJ. This study was partially funded by the MAPP program.
The Modeling, Analysis, Predictions, and Projections (MAPP) Program is a competitive research program in NOAA Research’s Climate Program Office. MAPP’s mission is to enhance the Nation’s and NOAA’s capability to understand, predict, and project variability and long-term changes in Earth’s system and mitigate human and economic impacts. To achieve its mission, MAPP supports foundational research, transition of research to applications, and engagement across other parts of NOAA, among partner agencies, and with the external research community. MAPP plays a crucial role in enabling national preparedness for extreme events like drought and longer-term climate changes. For more information, please visit www.cpo.noaa.gov/MAPP.