Poleward moisture transport by a Recurving Tropical Cyclone and its effect on Midlatitude Precipitation

Tropical cyclones (TCs) can cause extensive damage due to strong winds, storm surge, and rainfall. These systems are capable of torrential downpours, producing flooding and forceful winds that damage buildings. Past studies and forecasts have focused on the immediate impacts surrounding the area of a TC; however, few studies have examined the effects that TCs have away from their immediate areas. The focus of this study is to examine the moisture properties of Hurricane Ike, the properties of the storm's pre-existing conditions, and how Ike contributed to the intensification of precipitation poleward from itself. Version 3.1 of the Advanced Research version of the Weather Research and Forecasting model (WRF-ARW) was initialized to simulate Hurricane Ike on 13 September 2008 at 0000 UTC and on 12 September 2008 at 1200 UTC, with both ending on 16 September at 0000 UTC. The WRF-ARW model was able to replicate the occurrence of Hurricane Ike in the real atmosphere. Comparisons between both simulations and observations illustrated differences in reference to each other, but the general structure of the precipitation, water vapor, and temperature fields were similar. To test the sensitivity of rainfall accumulations to the presence of Ike, another simulation was run with Ike removed at the initialization of the second simulation. Initial analysis of the Ike removal scheme revealed a decrease in the moisture parameters; however, further study is needed to quantify Ike's impact. This study offers insight into forecasting issues with areas poleward of tropical cyclones such as Hurricane Ike.