Hurricanes (and some tropical storms) typically produce widespread rainfall of 6 to 12 inches or more, often resulting in severe flooding. In the past 30 years in the U.S., inland flooding has been the primary cause of tropical cyclone-related fatalities. Large amounts of rain can occur more than 100 miles inland where flash floods and mudslides are typically the major threats. The risk from flooding depends on a number of factors: the speed of the storm, its interactions with other weather systems, the terrain it encounters, and ground saturation.
In general, the rains are generally heaviest with storms moving less than 10 mph. Although the heaviest rain usually occurs along or near the cyclone track in the period six hours before and six hours after landfall, these storms can last for days, as was the case with Hurricane Mitch in 1998.
Even storms that fall below hurricane strength can produce copious amounts of rain and severe flooding.
With the groundwater table in the Cayman Islands being very high, it does not take much rain for the ground to become saturated. All low lying areas inland are therefore vulnerable to flooding which is made worse by wave action and storm surge.