Hurricane Dean

Pre-Landfall 1 | Summary
Posting Date: August 19, 2007, 7:00:00 PM

As of 5:00 PM EDT, Category 4 Hurricane Dean was located about 50 miles south of Kingston, Jamaica. Maximum sustained winds are 145 mph—unchanged from this morning. Minimum central pressure has risen very slightly to 930 mb. Dean is currently exhibiting concentric eyewalls, with the strongest winds in the outer eyewall. The capital, Kingston, will feel the effects of strong hurricane force winds and battering waves, despite the fact that the center will remain offshore. Hurricane force winds extend 60 miles from the center of the storm; tropical storm force winds extend to 205 miles. The good news is that the resort area of Montego Bay, which is on the northwest side of the island, should fare better as a result of being protected by the island's mountainous interior. However, two thirds of Jamaica's exposure, which AIR estimates at USD35 billion insurable, is in the parishes around Kingston. There are obvious comparisons to be made between Hurricane Dean and Hurricanes Gilbert (1988) and Ivan (2004). Dean is slightly stronger than Gilbert, which caused enormous damage in Jamaica; but Gilbert's track was closer to Kingston and therefore the winds experienced were slightly stronger—on the order of 10 mph higher. Ivan, which made a last minute side-step around Jamaica in 2004, took a slightly more southerly track than Dean and brought wind speeds as much as 15-20 mph lower to the capital. Forecasters expect coastal storm surge flooding from Hurricane Dean of 7 to 9 feet above normal tide, as well as rainfall amounts of 5 to 10 inches. As much as 20 inches of rain are possible in some pockets, increasing the risk of flash floods and mudslides. Hurricane Dean is currently moving to the west at near 20 mph and this general motion is expected to continue for the next 24 hours. The current NHC forecast track puts the center of the storm just 20-25 miles off the coast of Portland Point, Jamaica's most southerly point. Fortunately, this stretch of the coast is relatively sparsely populated. Nevertheless, exposures here can be expected to sustain significant damage. Poorly constructed single-family houses and mobile homes can be destroyed by 145-mph winds. On the other hand, relatively few such residences in Jamaica are likely to be insured. Better constructed homes may experience significant roof and even wall damage, exposing contents to heavy rains. The Jamaican power company switched off power to the island at 10:00 a.m. local time as a precautionary measure. Residents were urged to move to evacuation centers, but many are reported to have ignored the advice. The NHC currently expects Dean to continue generally westward—tracking about 75-80 miles south of Grand Cayman—and head toward Mexico's Yucatan peninsula. The waters here in the northwest Caribbean are warmer than any Dean has experienced thus far, and there is still a chance that Dean will intensify to a Category 5 hurricane on its trajectory toward Mexico. In 2005, Hurricane Wilma devastated the so-called "Mayan Riviera" resorts of Cozumel and Cancun, where rebuilding continues even today. However, the current forecast track for Dean takes the storm well south of Cozumel, and into a relatively sparsely populated stretch of coast. While Dean may regain some strength after crossing the Yucatan and reemerging into the southern Gulf of Mexico, track guidance models are currently in good agreement that Dean's second and final landfall will be in Mexico, well away from offshore interests along the Texas coast. Once again, however, it is important to emphasize that there remains considerable uncertainty with respect to both the future track and intensity of this storm. Yesterday, Hurricane Dean tracked about 100 miles south of the Dominican Republic and about 90 south of Haiti overnight, putting the island of Hispaniola well within Dean's tropical storm force windspeed footprint, but out of reach of hurricane force winds. Six poorly constructed homes are reported to have been destroyed and 200 others damaged. One person was reported killed by flying debris and several others by high surf. Up to 6 inches of rainfall fell in some isolated areas. Haiti's deforested mountains are particularly vulnerable to deadly mudslides, but no serious slides have as yet been reported. On Friday, Hurricane Dean threaded the islands of Martinique and St. Lucia, lashing both with strong winds and heavy waves. Roofs were blown off and windows were broken by flying debris. Large numbers of trees were downed. Officials in Martinique report that 100% of the banana crop was destroyed on the island. The AIR tropical cyclone team has run scenarios using information about Dean’s meteorological parameters and the storm’s actual and projected track through the Caribbean. Eleven of these are now posted on the scenarios page of this website, where CATRADER and CLASIC/2 clients can view wind speed and loss maps. In addition, event sets representing the full range of simulated scenarios are now available for download. Note that the loss estimates are for Jamaica only.

Pre-Landfall 1 | Downloads
Posting Date: August 19, 2007, 7:00:00 PM