Economic value of tropical cyclone conditions of readiness

U. S. Military bases are especially vulnerable to tropical cyclones (TCs) because they concentrate extremely expensive equipment in a small area. A TC hit at a base can result in upwards of 2 billion dollars in damage, as demonstrated by the recent loss of F-22 aircraft at Tyndall Air Base during Hurricane Michael. To mitigate these events, the Department of Defense defines tropical cyclone conditions of readiness (TCCOR), a set of preparedness levels that are adhered to by bases in preparation of an approaching TC. TCCOR are set by base commanders and are dependent on the likelihood of 50-knot sustained winds impacting the base within a forecast time. These TC-CORs generally drop from V (generally seasonal preparedness) to IV (50 kt or higher winds possible within 72 h); III (50 kt or higher winds possible within 48 h), II (50 kt or higher winds expected within 24 h), and I (50 kt or higher winds expected in 12 h or occurring now). Each TCCOR is associated with a specific set of preparedness actions whose cost generally increases as the TCCOR level drops. As preparing a base for a specific TCCOR level can be extremely time consuming and expensive, it is important that we assess the economic value of the preparation. In this work, we develop a simple cost-loss/savings model to estimate and compare the economic value of skillful TC forecasting against a no-skill forecast baseline. The cost-loss/savings model developed demonstrates that skilled forecasts offer considerable savings over non-skilled forecasts. The algorithm has been implemented in an Excel spreadsheet so that it can be customized to specific bases of interest.