Aviation Weather Conditions Prior to Tropical Cyclone Landfalls

When a tropical cyclone threatens a given location, the focus is typically on issues such as “When will tropical storm force winds begin to affect that location?” and “What will the maximum winds be and when will those winds be experienced at that location?” While these questions are important, when considering an evacuation, especially the evacuation of general aviation aircraft, another important question is “What will the weather conditions be just prior to the time a tropical cyclone affects a location (i.e., during the time when an evacuation is being carried out)?”

The weather conditions experienced during the time when evacuations are being executed may, in fact, differ from storm to storm. For example, many locations affected by Hurricane Matthew in 2016 had relatively poor weather conditions for several days leading up to the storm’s arrival, while many locations affected by Hurricane Katrina in 2005 generally had good weather conditions up until about 12 hours before the storm’s arrival.

Being able to quantify the amount of time before conditions deteriorate for a number of storms will help us to better understand how to prepare and may give insight into the overall evolution of tropical cyclones. To accomplish this, storm tracks and reports from the National Hurricane Center and surface hourly data from the National Climatic Data Center were used to create analyses of aviation weather conditions for the 120 hours leading up to the first tropical storm force winds experienced at an observing site. Analyses were created for each individual storm as well as aggregates of storms based on strength, location of impact, and time of impact.