The National Hurricane Center in Miami issued its report on Hurricane Ivan on Tuesday, confirming that the storm was at Category 4 on its closest approaches to the Cayman Islands.
The 38-page report, compiled by Stacy R. Stewart, will become the principal historical document concerning the life of Hurricane Ivan.
For the record books, the strongest maximum sustained winds recorded in the Cayman Islands during Hurricane Ivan were 130 knots, or 149.7 miles per hour at 8:45 am local time. These readings came from a privately-owned Automated Weather Observing System in West Bay, one of only two systems – out of eight on the island – that were still operational at the time.
In the synoptic history section of the report, it states Ivan reached Category 5 strength on the Saffir-Simpson Hurricane Scale three times, two of which occurred right before and right after the storm passed Grand Cayman.
At 1 pm local time on September 11, the storm reached its maximum intensity of 145 knots, or 167 miles per hour, as it was moving away from Jamaica. It only maintained the Category 5 status for six hours before weakening back to a Category 4 storm.
The report indicates that Ivan was a Category 4 storm from approximately 1 am on Sunday, September 12 until 1 pm that afternoon, which incorporates the time when the hurricane’s eye was at its closest approaches to Grand Cayman.
After passing 80 nautical miles west of Grand Cayman, Ivan re-strengthened to a category 5 for a third and final time.
Although Ivan was a Category 4 when closest to Cayman, Chief Meteorologist Jeff Tibbetts pointed out that it was a Category 5 when tropical force winds began affecting the islands at 1 pm on Saturday. However, when hurricane force winds first began affecting Grand Cayman at 1 am on Sunday, the storm had weakened to a Category 4 status.
The report, however, acknowledges that the storm was very strong when it was closest to Grand Cayman.
‘Although Ivan was weakening while the centre passed south of Grand Cayman on 12 September, the hurricane brought sustained winds just below Category 5 strength to the island. This resulted in widespread wind damage and a storm surge that completely over-swept the island.’
In speaking about that damage in the Cayman Islands, the report later indicates that ’95 percent of the homes and other buildings (which generally follow South Florida’s building codes) were damaged or destroyed.’
Most of the statistical data used in the report was supplied by the National Meteorological Service of the Cayman Islands. Data was also obtained from the hurricane hunter aircraft used by the United States National Weather Service.
In addition to classifying the storm as a Category 4 when it passed Cayman, the report shows that the peak recorded wind gust here was 149 knots, or 171 miles per hour.
Mr. Tibbetts said that the gusts were probably much higher here.
‘We’ve always said we believe that there were higher wind gusts,’ he said, noting that only observations actually recorded can be used in their reports. ‘We think that we could have had wind gusts over 200 miles per hour, although exactly how much over is a question mark.’
The other functional Automated Weather Observing System on Grand Cayman – in Savannah, supposedly recorded a wind gust of 190 mph, but Mr. Tibbetts said the observation was not written down in the proper scientific manner.