Using internal research and development funds, Halcrow has developed the first version of the Regional Caribbean Sea Storm Surge model that also includes the contiguous Gulf of Mexico using the MIKE21 Flexible Mesh (FM) Hydrodynamics (HD) model.
The wind model used (from the cyclone generator hard-wired to the MIKE21 tools) is the parametric wind model of Young and Sobey (1981) without provision for land dissipation/wind decay effect when the storm is traversing over land.
The FM HD module includes astronomical tides and can be run coupled with the Spectral Wave (SW) module to dynamically link wind- and pressure-induced storm surge, tide, and wave-induced setup through the inclusion of the radiation stress field in two-way coupling to yield the combined storm surge elevation at any coastal location.
As it is presently formulated, the model can provide storm surge elevation envelopes at coastal locations before the storm makes landfall. The parametric wind field model uses the standard hurricane inputs available from the National Hurricane Centre’s HURDAT dataset supplemented with additional data on the storm track, maximum wind speed, central pressure, and the radius to maximum wind (RMW) available from the snapshots of wind field in the HRD’s H*WIND dataset (surface wind analysis for post-1993 hurricanes though the same for selected hurricanes for the pre-1994 period is also available). For storms not included in the H*WIND dataset, Vickery et al. (2000)’s empirical relations based on latitude and central pressure deficit are used instead.
In order to include tide-surge interaction, the FM HD model was also run with tides only with the offshore boundary conditions provided by predicted tides generated using Global Tide Model (GTM) tidal constituents (0.25 degree intervals) and the results compared with measurements at selected nearshore NOAA tide gages for qualitative agreement.