At the end of August 2020, a unique event was observed in the Gulf of Mexico - the occurrence of two tropical cyclones within close spatio-temporal proximity to one another and their combined ocean response. Marco made landfall first, as a tropical storm on 24 August 2020, having weakened from a Category 1 hurricane before landfall. Laura made landfall on 27 August 2020 as a Category 4 hurricane, having intensified from a Category 2 within 24 hours prior to landfall.
The evolution of sea surface temperature (SST) anomalies in the Gulf of Mexico before, during, and after Tropical Cyclones Laura and Marco can be explored using the NASA Multi-Scale Ultra-High Resolution (MUR) SST dataset. A significant ocean response is clearly seen in the wake of the hurricane tracks, with waters approximately 2°C cooler compared to normal conditions across the entire eastern Gulf of Mexico. It is common to see cold wakes, or areas of cooler water, along or to the right of hurricane tracks in association with wind-induced water column mixing that brings cooler waters at depth to the surface. These cold signatures are generally patchy and spatially confined. What is unique about the ocean response to Tropical Cyclones Laura and Marco is the extent of cooling, which spans the entire eastern Gulf of Mexico.