| On 07SEP95,  Hurricane Luis  intensified from 
about 100 kt winds and 940 mb minimum sea-level pressure (MSLP) 
to 120 kt and 935 mb MSLP as it moved northwestward away from 
the Lesser Antilles. During the course of the day (UT) an outer 
concentric eyewall formed surrounding the original eyewall at 50 
nmi radius. Early on 08SEP95, the new eyewall became the 
dominant feature and the maximum winds decreased to about 100 kt 
again. Natural eyewall cycles such as Luis' are virtually identical 
to the expected result of the  STORMFURY  modification 
experiments carried out in the 1960s. Two radar composites 
transmitted in real time from a NOAA research aircraft to 
forecasters at the National Hurricane Center show Luis' well 
defined outer eyewall surrounding the dissipating partial inner 
eyewall: More profound weakening through a similar eyewall replacement was the most important factor in avoiding a major disaster when Hurricane Opal approached the Gulf Coast after attaining a MSLP of 916 hPa overnight 03-04OCT95. | 
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