A very bad day in Jamaica

It could have been much worse, but it is very bad for Jamaica. Hurricane Dean's northern eyewall is just offshore the southern tip of Jamaica, bringing sustained Category 2 hurricane winds to southern Jamaica. A recent wind analysis prepared by NOAA's Hurricane Research Division (Figure 1) at 3:30pm EDT today shows winds of Category 1 strength (>65 knots, or 74 mph) already affecting the east end of the island. By extrapolating this wind field over the island to the west-northwest, in anticipation of Dean's track, it is apparent that perhaps 90% of the island will experience sustained winds of 74 mph or greater. At 4pm EDT, Kingston, on the southern side of the island, recorded sustained winds of 81 mph before the instrument failed. We can expect that the southern 1/3 of the island, including Kingston, will receive sustained winds of Category 2 strength--96 to 114 mph. Category 3 and higher winds will be confined to the southernmost 5% of the island, and it appears that the Category 4 winds will stay offshore. The portion of the island affected by the Category 3 winds is very sparsely populated.

Jamaica will probably suffer a billion dollars in damage from Dean, perhaps more. The high winds and rains of up to 20 inches will no doubt claim lives, though probably not nearly as many as the 45 who died during Hurricane Gilbert of 1988. Gilbert cut straight across Jamaica as a Category 3 hurricane with 125-130 mph winds, doing $4 billion in damage. Kingston measured sustained winds of 116 mph during Gilbert; I expect the top winds in Dean will be 10 mph slower than that.


Figure 1. Wind analysis of Dean at 3:30pm EDT 8/19/07. Areas in yellow mark winds of Category 1 and stronger (65kt, 74 mph). Dean was moving west-northwest, and the most intense winds (120kt, 140 mph) should stay barely south of the island. Image credit: NOAA's Hurricane Research Division.

I'll have a full update Monday morning at about 10am EDT.

Jeff Masters