Cold wakes associated with 2018 Hurricanes Michael and Willa
Hurricanes Michael and Willa of 2018 were both storms that intensified rapidly, one in the Gulf of Mexico and the other in the Eastern Pacific Ocean. Hurricane Michael was one of strongest storms (peak winds of 155 mph) to make landfall in the continental United States, devastating the Florida panhandle. Here we focus on examining the sea surface temperature (SST) response associated with these hurricanes, specifically their cold wakes, using the NASA Multi-Scale Ultra-High Resolution (MUR) SST dataset (doi: 10.5067/GHGMR-4FJ04). Cold wakes are trails of cold subsurface water that have been brought to the surface as a result of wind-induced mixing and turbulence (Chen et al., 2017).
Figure 1 shows the evolution of SST anomalies in the Gulf of Mexico during Hurricane Michael. Before Michael (2 October 2018), waters were approximately 2°C warmer than normal in the Eastern Gulf Mexico. The warm anomalies contributed to the intensification of Michael prior to landfall. On 10 October 2018 Michael made landfall as a Category 4 hurricane near Mexico Beach, Florida. The cold wake associated with Michael was clearly observed as waters approximately 3°C cooler from normal on 10 October 2018 (during landfall) along the hurricane track that persisted several days after landfall (14 and 17 October 2018).
Hurricane Willa formed in the Eastern Pacific Ocean making landfall on 23 October 2018 as a category 4 hurricane. Like Michael, Willa intensified quickly prior to landfall due to warm ocean conditions, although the ocean state was not as warm as the Gulf of Mexico. Figure 2 show the evolution of SST anomalies in the Eastern Pacific Ocean during Hurricane Willa. The cold wake associated with Willa was clearly observed as waters cooler than 3°C from normal on 23 October 2018 (during landfall) along the hurricane track that persisted several days after landfall (26 and 28 October 2018).