List of Category 4 Atlantic hurricanes
A Category 4 Atlantic hurricane is a tropical cyclone that reaches Category 4 intensity on the Saffir–Simpson scale. Category 4 hurricanes that later attained Category 5 strength are not included in this list. The Atlantic basin includes the open waters of the Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Category 4 is the second-highest hurricane classification category on the Saffir–Simpson Hurricane Scale, and storms that are of this intensity maintain maximum sustained winds of 113-136 knots. Based on the Atlantic hurricane database, 143 hurricanes have attained Category 4 hurricane status since 1851, the start of modern meteorological record keeping.
Statistics
Wind, damage, and storm surge statistics
Category 4 hurricanes have maximum sustained winds of 113-136 knots. "Sustained winds" refers to the average wind speed observed over one minute at a height of 10 meters above ground. Gusts can be up to 30% higher than the sustained winds. Mobile homes and other buildings without fixed structures can be completely destroyed, and the lower floors of sturdier structures usually sustain major damage. In addition to the winds, the cyclones generally produce a storm surge of 13–18 feet above normal, potentially causing major beach erosion. Heavy, irreparable damage and/or near complete destruction of gas station canopies and other wide span overhang type structures are also very common, and mobile and manufactured homes are often completely destroyed. Low-level terrain may be flooded well inland, as well. In addition, Category 4 hurricanes are often Cape Verde-type hurricanes. Cape Verde hurricanes are usually the strongest, and their track sometimes points them towards the United States, or other land.History of Category 4 Atlantic hurricanes
The number of Category 4 and 5 hurricanes appears to have nearly doubled in occurrence from 1970 to 2004. It is possible that the increase in Atlantic tropical storm and hurricane frequency is primarily due to improved monitoring.Due to growing population in major coastal cities, many areas have become more vulnerable to strong hurricanes, especially categories 4 and 5.
Meteorological measurements
All of the storms listed in this analysis are listed in chronological order, but they also list the minimum central pressure and maximum sustained winds. Each of these meteorological readings are taken using a specific meteorological instrument. For modern storms, the minimum pressure measurements are taken by reconnaissance aircraft using dropsondes, or by determining it from satellite imagery using the Dvorak technique. For older storms, pressures are often incomplete, typically being provided by ship-reports or land-observations. None of these methods can provide constant pressure measurements; thus it is possible the only measurement occurred when the cyclone was at a lesser strength. Sustained winds are taken using an Anemometer at 10 meters above the ground.Climatology
A total of 94 hurricanes in the Atlantic Ocean Basin, including the Gulf of Mexico and the Caribbean, have reached Category 4 status as their peak intensity.Most Category 4 hurricanes occur during September, with 51 storms occurring in that month. This coincides with the average peak of the Atlantic hurricane season, which occurs on September 10. Most Category 4 hurricanes develop in the warm waters of the Gulf of Mexico and the Caribbean Sea. Several Category 4 hurricanes are Cape Verde-type hurricanes.
There have been no Category 4 hurricanes to form in either May or December, or in any other month outside the traditional bounds of the Atlantic hurricane season.