26 August 2009

Gratz on Danny

A cross-post from the ICAT Damage Estimator, by Joel Gratz:

With the current (Wednesday PM) track models showing Danny skirting the North Carolina shoreline and heading toward southeastern New England, I put together a list of similar storms from the ICAT Damage Estimator database.

Alma, 1962
Barbara, 1953
Bob, 1991
Carol, 1954
Edna, 1954
Esther, 1961
Gloria, 1985
Storm #7, 1944
The average damage for these storms if they all struck in 2009 is about $6 Billion per storm. However, these storms made landfall at varying strengths, from Tropical Storm to Category Three. Since Danny is projected to be a Category One storm during the time of highest impact to land, we can massage the historical damages to see how much damage the storms would cause if they were all Category One storms. From our 2008 paper in the Natural Hazards Review:

Damage from Category Two = 6x the damage from Category One

Damage from Category Three = 18x the damage from Category One

After making this adjustment, and holding constant the damage from the two Tropical Storms on the list (Alma and Esther), the average damage per storm is about $435 Million. This provides a good initial damage estimate for Danny. Please keep in mind that this is an estimate of TOTAL ECONOMIC DAMAGE, and insured damage usually runs about 50% of the total economic damage. Let’s see how this works out in the coming days.

Thanks for reading.

Here is a screenshot of the analogous storms: