Seasonal Hurricane Damage

Real-Time Seasonal Hurricane Damage Potential Forecasts

New C3WE science has devised a method to assess the damage potential of the upcoming hurricane season due to winds and coastal surge. In much the same way that current seasonal forecasts forecast hurricane numbers, this new view of the hurricane season uses predicted sea surface temperature patterns and environmental winds from the National Centers for Environmental Prediction (NCEP) ensemble Climate Forecast System (CFS) to infer the key drivers of hurricane damage: namely, hurricane intensity, hurricane size and hurricane translation speed.

The resulting seasonal Cyclone Damage Potential (CDP) index uses a scale from 1 to 10 to assess likely seasonal damage potential relative to other seasons. To put this range into perspective, average historical CDP, over the years 1981 through 2010 is 3.7. The forecast issued July 1, 2017 for an average CDP of 5.4 is a shift up from the forecast issued April 1, 2017 of 3.2. To put this into context, the highly active 2005 season, for example, had a CDP of 6.3.  However, we caution that high CDP does not necessarily correspond with high loss, because CDP forecasts damage potential for the entire North Atlantic and does not necessarily correspond to landfalling damage potential.

Histogram of seasonal cyclone damage compared to climatology

Damage potential forecasts were produced using 124 CFS forecasts made throughout March 2017 for the April 1 forecast and throughout June for the July 1 forecast. The figure shows the spread of these forecasts (red line for April 1 and yellow line for July 1) compared to the long-term historical damage potential (black line) and shows the July forecast distributions are shifted higher than the historical distribution. This view is generally in line with the seasonal forecasts of tropical cyclone numbers that are higher than average this year.

New damage potential forecasts will be released for the 2018 season in early 2018. Feedback welcome to James Done: done@ucar.edu or to C3WE: c3we@ucar.edu

For more information, see the UCAR news story or the peer-reviewed scientific paper: ‘Estimating impacts of North Atlantic tropical cyclones using an index of damage potential’.