Probabilistic Track Generation for Hurricane Storm Surge Estimates

Storm surge is a major source of devastation for hurricane events, and as such it is important to understand the uncertainty associated with storm surge forecasting. Uncertainty in predicted storm surge can be quantified by synthesizing a suite of probable storm tracks that are based on errors in predictions of previous hurricanes and computing storm surge with a suitable model. Davis et al (2010) developed an approach to track generation based on cross track errors in the official National Hurricane Center forecast tracks. In this work, we extend the methods from Davis et al (2010) to include along track and maximum wind speed errors. Errors in the NHC forecasts are used to compute probability distributions that are sampled to generate synthetic tracks on either side of the official forecast, with each track having an equal likelihood of occurrence. Storm surge for each track is then computed with the ADCIRC model (Westerink et al, 2008) to generate probability of exceedance maps and worst-case potential storm surge (maximum of maximums).

Davis, J. R., Paramygin, V. A., Forrest, D., and Sheng, Y. P. (2010). Toward the probabilistic simulation of storm surge and inundation in a limited-resource environment. Mon. Weather Rev., 138(7):2953–2974.

Westerink, J., Luettich, R., Feyen, J., Atkinson, J., Dawson, C., Roberts, H., Powell, M., Dunion, J., Kubatko, E., and Pourtaheri, H. (2008). A basin- to channel-scale unstructured grid hurricane storm surge model applied to Southern Louisiana. Mon. Weather Rev., 136:833–864.