This calculator will let you estimate the IKE and Surge Destructive Potential based on estimates of the outermost extent of tropical storm (TS), 50 kt, and Hurricane Force (H) winds in each storm quadrant. The results will give you ball park estimates if you use the operational wind radii. These estimates are based on some very coarse wind field assumptions. An improved estimate would come from a gridded wind analysis or model input data using the methods described in Powell and Reinhold 2007.
Update: Please note that IKE calculations prior to October 23, 2012 used a surface air density 0f 1.0 Kg per cubic meter. Current calculations (after October 23, 2012) use a more representative value of 1.15 kg/cubic meter based on GPS sonde measurements in hurricanes.
The boxes on the satellite photo indicate the radius (in nautical miles) of 34kt, 50 kt, and 64 kt winds in each quadrant of the storm.
For example NW50(nm) is the radius of 50 kt winds in the Northwest quadrant of the storm.
The Storm Total IKE TS-50 (TJ) box is the result showing the amount of kinetic energy in Terra Joules contributed by winds greater than or equal to tropical storm force (34 kts) but less than 50 kts.
The Storm Total IKE 50-H (TJ) box is the result showing the amount of kinetic energy contributed by winds greater than or equal to 50 kts but less than hurricane force.
The Storm Total IKE H (TJ) box is the result showing the amount of kinetic energy contributed by winds greater than hurricane force (64 kts).
The SDP box is the Surge Destructive Potential Rating based on a scale of zero to 6. SDP is interpreted similar to the Saffir SImpson scale in that the most destructive storms are rated above 5 and the least destructive storms < 1.
The Wind Destructive Potential (WDP) is not included in the calculator because it cannot be estimated very well from wind radii. WDP is extremely sensitive to strong winds. The most important contributor to the WDP comes from the part of the storm with winds greater than hurricane force, so a gridded analysis is required to estimate WDP (such as on the H*Wind analyses).
Use Cases for I.K.E. from Operational Quantities-Mark Powell, 10-29-2008 updated 12-2012 to include air density and revise the IKEh calculation