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Part of the report from the University of South Alabama.......... Powerful Katrina is now moving slightly north of due west and will continue to curve more toward the northwest over the next 24 hours. The storm, although temporarily re-organizing its eyewall structure, will grow stronger over the weekend and a poses a grave threat to the north-central Gulf Coast by Monday. Hurricane Katrina is presently undergoing an eyewall replacement cycle where the original eyewall becomes surrounded by a newly developing eyewall farther out from the center. Over a period of 12-24 hours, the inner eyewall dissipates and the storm temporarily weakens. However, the outer eyewall then becomes dominant and begins a contraction process which causes the eye to shrink and the storm then grows stronger. Right now, the inner eyewall of Katrina is dissipating and the storm is temporarily weakening; however a new outer eyewall is forming which will eventually begin to contract toward the center of the storm, leading to another round of significant intensification by tonight or early Sunday. It is during this next intensification round that Katrina will possibly reach Category 5 strength. By Sunday, larger-scale weather systems in the central United States will force a weakening of the eastern U.S. high pressure ridge, which will ultimately turn Katrina northward... toward extreme Southeast Louisiana, Mississippi, and possibly southwest Alabama. It appears that Katrina will arrive on the coast of Louisiana late Monday morning and on the Mississippi coast Monday afternoon before progressing inland through the state of Mississippi with serious effects eastward into western Alabama. All interests in New Orleans need to prepare for the worst. There is also the possibility that Katrina could turn toward the north-northeast just prior to landfall as it interacts with a jet stream disturbance over the central U.S.; in this event, the core of the storm may impact as far east as the Mobile area. Katrina is expected to be a category 4 storm at landfall. It is possible that Katrina may reach category 5 intensity over the Gulf of Mexico loop current by Sunday before probably weakening back to a category 4 by landfall. Because of the unique geography of the LA/MS area, an intense storm approaching SE Louisiana from the south will pile huge amounts of water into Lake Pontchartrain and the western portions of the Mississippi Sound, thereby producing storm surge elevations higher than they would otherwise be along a straight coastline. Storm surge heights could reach 18-20 feet in this region, should Katrina move inland near or just to the east of New Orleans as a category 4 storm. |