Tropical cyclones are powered by warm sea surface temperatures and, all other things being equal, the warmer the ocean surface, the more intense the storm. However, tropical cyclones cool the surface ocean by mixing it with cooler water drawn from deeper parts of the water column. This ``cold wake" acts as a negative feedback -reducing the storm's intensity. Our ability to incorporate this information in forecasts is limited by a lack of observations of the surface ocean within tropical cyclones, particularly in shallow seas inaccessible to autonomous Argo floats. Here, we show observations of the upper ocean response to five tropical storms obtained from a novel source: sea turtles instrumented with oceanographic sensors from the IMOS animal tracking facility. The turtle observations captured ocean processes, such as mixing induced ocean cooling, that are important for storm forecasting. In comparisons, an ocean reanalysis system fails to capture many of the processes responsible for the surface ocean cooling. Having shown the utility of the observations for ocean-tropical cyclone interaction studies, we discuss the role that a turtle based observing system could play in monitoring and forecasting tropical cyclones in both Australia and worldwide.