Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 2:03 PM GMT on March 24, 2006
The National Hurricnae Center has released its final report on Hurricane Rita. The report revises Rita's strength at landfall downward by 5 mph. Doppler radar data not available at the time the storm hit suggests that Rita's peak winds were 115 mph, not 120 mph as was previously thought. However, Rita was still a tremendously strong Category 3 hurricane at landfall, and carried a storm surge characteristic of a Category 4 hurricane with her to shore. The NHC report mentioned that storm surge values were hard to figure out, since most of the tidal gauges were destroyed. A maximum storm surge of 15 feet and perhaps a few feet higher probably occurred along the Louisiana coast to the right of where the eye came ashore. This storm surge destroyed nearly every building in the towns of Holly Beach, Cameron, Creole, and Grand Cheniere. The surge reached up to 30 miles inland in same locations, and flooded downtown Lake Charles-- with up to six feet of flood waters. Rita's central pressure at landfall is estimated at 937 mb based on dropwindsonde data from the Hurricane Hunters. This landfall pressure is the lowest on record in the Atlantic basin for a Catgegory 3 hurricane with 115 mph winds. Similar to Katrina one month earlier, the relatively weak winds in Rita for such a low pressure resulted from the fact that Rita grew to enormous size, spreading its broad pressure field over a huge area.
Figure 1. The eye of Hurricane Rita shortly after reaching its peak intensity. Rita had 180 mph winds and the 4th lowest sea-level pressure on record, 895 mb. Image taken from the NASA's MODIS satellite.
Rita's peak intensity while out over the warm waters of the Gulf of Mexico's Loop Current was higher than previously thought--the maximum winds were 5 mph stronger, and the central pressure 2 mb lower. There was a 6-hour gap in hurricane reconnaisance flights during the time that Rita underwent its rapid deepening phase, and it is thought the the storm continued to strengthen for a few hours while there was no one there to see it. Rita's maximum winds are now estimated at 180 mph, and her lowest pressure, 895 mb. This is the fourth-lowest pressure on record in the Atlantic, behind 882 mb in Wilma (2005), 888 mb in Gilbert (1988), and 892 mb in the 1935 Florida Keys hurricane. Rita's pressure dropped an astonishing 70 mb in just 24 hours, and strengthened from a tropical storm to a Category 5 hurricane in less than 36 hours just after it passed 70 miles south of the Florida Keys. We are very fortunate that this deepening phase did not start 24 hours earlier and the storm did not track 70 miles further north, or else the U.S. might have had two hurricane disasters with major loss of life in 2005. The Florida Keys need a full 72 hours of evacuation time to get everybody out, and the evacuation order would likely have been given only 24 hours in advance. Next to New Orleans, the Keys are the number one most vulnerable place in the U.S., and a storm that causes major loss of life there is probably only a matter of time.
Figure 2. Radar image of Hurricane Rita as it began its explosive deepening to a Category 5 hurricane, barely sparing the Florida Keys.
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