Sunday, August 26, 2012

Looking back at Hurricane Georges (1998)

The National Hurricane Center moved Isaac's forecast track to the west today, as some well-known models, like the GFS, GFDL and HWRF models predict a more westward solution for Isaac's track. The new track and intensity forecasts resemble Hurricane Georges (1998), although Georges was a category-2 hurricane for most of its track in from Cuba.

 This map shows the historic track for Georges. Hourly position and intensity data are provided by Dr. Elsner and Dr. Jagger at Florida State University. The image looks a bit small on this blog, but it can be downloaded. Check back later for surge data to be added to this plot. The SCIPP program has identified 68 high water marks from this storm, which are now included in the SURGEDAT database. Until these points are plotted in a color-coded map (again, check back soon), here is a list of selected high water mark observations from Hurricane Georges.

Hurricane Georges (1998) Storm Surge Observations (feet)

Fort Morgan, AL   11.9
Pascagoula- Bayou Chico, MS 9.6
West Mobile Bay, AL 9.3
Gulf Shores, AL 9
Biloxi (Point Cadet) 8.9
 NE Bardene Bay, LA 8.9
Downtown Mobile, AL 8.5
Gulfport Harbor, MS 8.1
Pensacola Beach, FL 7.7
Bay St. Louis, MS 5.8
Panama City Beach, FL 5.2
Lake Pontchartrain Causeway, LA 4.7
Frenier, LA (West end Lake Pont) 4.7

Storm Tide Levels (Tides not removed from data)
Mississippi Coast high water mark 12.14
Alabama Coast high water mark 10.83
Mobile River, AL 8.94
Navarre Beach, FL 8.5
Pascagoula River, MS 8.36

Those are some selected observations. Again, Georges was more intense at this stage of the game than Isaac, and recent research has indicated pre-landfall winds correlate better with surge heights than winds at landfall (Jordan and Clayson 2008; Needham and Keim 2012- in press). This hopefully means that Isaac's surge levels will be somewhat lower than Georges' if Isaac does indeed follow a similar track to Georges.

Stay tuned for more surge-related information as Isaac approaches the U.S. Gulf Coast.

1 comment:

  1. The current forecast has a trajectory just to the west of Georges. Do you have any thoughts on how that impacts surge heights?