Hurricane Dean
Hurricane Dean was a powerful and destructive tropical cyclone that became the strongest of the 2007 Atlantic hurricane season. It ties with Hurricane Mitch for the tenth most intense Atlantic hurricane by atmospheric pressure. Additionally, it made the fifth most intense landfall in the basin by central pressure. A Cape Verde hurricane that formed on August 13, 2007, Dean took a west-northwest path from the eastern Atlantic Ocean through the Saint Lucia Channel and into the Caribbean Sea. It strengthened into a major hurricane, reaching Category 5 status on the Saffir–Simpson scale before passing just south of Jamaica on August 20. The storm made landfall on the Yucatán Peninsula on August 21 at peak intensity. It crossed the peninsula and emerged into the Bay of Campeche weakened, but still remained a hurricane. It strengthened briefly before making a second landfall near Tecolutla in the Mexican state of Veracruz on August 22. Dean drifted to the northwest, weakening into a remnant low which dissipated uneventfully over the southwestern United States. Dean was the second-most intense tropical cyclone worldwide of 2007 in terms of pressure, only behind Cyclone George in the Australian region, and tied with Felix as the most intense worldwide in terms of 1-minute sustained winds.
The hurricane's intense winds, waves, rains and storm surge were responsible for at least 45 deaths across ten countries and caused estimated damages of US$1.66 billion. First impacting the islands of the Lesser Antilles, Dean's path through the Caribbean devastated agricultural crops, particularly those of Martinique and Jamaica. Upon reaching Mexico, Hurricane Dean was a Category 5 storm, but it missed major population centers and its exceptional Category 5 strength landfall caused no deaths and less damage than in the Caribbean islands it passed as a Category 2 storm.
Through the affected regions, clean up and repair took months to complete. Donations solicited by international aid organizations joined national funds in clearing roads, rebuilding houses, and replanting destroyed crops. In Jamaica, banana production did not return to pre-storm levels for over a year. Mexico's tourist industry took almost a year to rebuild its damaged cruise ship infrastructure.
Dean was the first hurricane to make landfall in the Atlantic basin at Category 5 intensity since Hurricane Andrew on August 24, 1992. Dean's Category 5 landfall was in a sparsely populated area and thus far less damaging than Andrew's, even though Dean was much larger, but its long swath of damage resulted in its name retirement from the World Meteorological Organization's Atlantic hurricane naming lists.
Meteorological history
On August 11, 2007, a vigorous tropical wave moved off the west coast of Africa, producing disorganized showers and thunderstorms. It encountered conditions favorable for gradual development, and on August 12 it gained organization and became a low. Strong upper-level easterly winds slowed development, but on August 13 the tropical wave gained enough organization that the National Hurricane Center designated it Tropical Depression Four. At this time it was centered about 520 mi west-southwest of Cape Verde. The depression was already exhibiting persistent deep convection in the western portion of its circulation. It moved quickly westward, south of a deep layered ridge, escaping the easterly wind shear that had been slowing its development and moving over warmer waters. At 1500 UTC on August 14, the depression was upgraded to Tropical Storm Dean while still 1450 mi east of Barbados. Even as its convection waned slightly that afternoon, its intensity grew, and convection flared in the center that night. Dry air and cooler air inflow from the north slowed structural development; nevertheless, ragged bands began to form on August 15. By mid-morning, a rough banding eye had formed, and by the next morning a full eye developed. The storm was upgraded to Hurricane Dean at 0900 UTC August 16, 550 mi east of Barbados.A strong ridge of high pressure continued to push the system west, towards the Caribbean Sea. That afternoon, convective banding and increasing upper-level outflow strengthened the storm to a Category 2 hurricane on the Saffir–Simpson scale. The eye disappeared briefly overnight, possibly as part of a diurnal fluctuation, but returned by the morning of August 17. At 0930 UTC on August 17, the center of Hurricane Dean passed into the Caribbean Sea through the Saint Lucia Channel between the islands of Martinique and St. Lucia. The northern eyewall passed over Martinique where a weather station in the island's capital of Fort-de-France reported 13 in of rainfall. By this time the eyewall had closed, forming a distinct eye, and in an environment of low wind shear and increasing ocean temperature the hurricane began to intensify rapidly. Hurricane Dean strengthened to a Category 3 hurricane by the evening of August 17. Satellite imagery showed that a well defined eye and numerous cyclonically curved convective bands remained over the Lesser Antilles. That evening, another reconnaissance aircraft reached the hurricane and discovered that it had strengthened into a Category 4 hurricane, and by 0600 UTC on August 18, Dean reached Category 5 intensity for the first time with 165 mph winds. The storm's wind radii increased in all quadrants as the storm grew in both intensity and size. At 0800 UTC August 18, Hurricane Dean passed directly over NOAA sea buoy 42059 which reported a significant wave height of 33 ft. On August 18, Hurricane Dean developed a double eyewall, indicating that an eyewall replacement cycle was taking place and causing short term fluctuations in intensity as Dean weakened back to a Category 4 hurricane. That afternoon the hurricane continued to improve its outflow, and its numerous spiral bands gave it a well defined satellite presentation. Hurricane Dean finished the eyewall replacement cycle early on August 19 with some trochoidal wobbles.
On the morning of August 19, the storm remained slightly weakened from its peak strength. As a Category 4 hurricane with wind speeds between 140 mph and 145 mph, the center of Hurricane Dean passed 90 mi south of Haiti, and that evening passed 25 mi south of Jamaica. Two weather stations on the island of Jamaica, one at Ingleside and the other at Morant Bay, both reported in excess of 13 in of rainfall. In contrast, the weather station at Les Cayes, Haiti recorded only 1.18 in of rainfall. Hurricane Dean intensified through the night of August 19 and reinforced its completed eyewall replacement cycle by forming a tight single-walled eye. At 0100 UTC August 20, the storm passed 120 mi to the south of Sea Buoy 42056, which recorded a significant wave height of 36 ft. A concentric eyewall was briefly observed again on the morning of August 20, but it did not last long. In conditions of low wind shear, Hurricane Dean moved westward over waters with increasingly high heat content, and the storm exhibited a classic upper-tropospheric outflow pattern. The high pressure system over the southeastern United States continued to steer the storm west towards the Yucatán Peninsula. The eyewall became even better defined throughout the day. The cloud tops cooled, the minimum central pressure fell, and its winds increased to 160 mph, making Hurricane Dean a Category 5 hurricane once again. This time, it was less than 210 mi from its first landfall.
Although many of the convective bands were already located over the Yucatán Peninsula, Hurricane Dean continued to intensify until the eye made landfall. As the eye moved over Mexico near the town of Majahual in the Costa Maya area, the NHC estimated surface level winds of 175 mph, making Dean the first storm to make landfall as a Category 5 hurricane in the Atlantic basin since Hurricane Andrew in 1992. At the same time, a dropsonde reading from the hurricane's eye estimated a central pressure of 905 mbar, making Dean the fifth most intense landfalling Atlantic storm in history and tying Dean with Mitch as the tenth most intense hurricane ever recorded in the Atlantic basin. The landfall itself occurred in a sparsely populated area of the Costa Maya region of the Mexican state of Quintana Roo near 18.7 N 87.8 W at 0900 UTC August 21 and brought with it a storm surge of 12–18 ft. A weather station at Chetumal reported 6.65 in of rainfall during Hurricane Dean's landfall. As expected, the landfall caused significant weakening of the storm; the eye filled and the cold cloud-tops warmed. The land severely disrupted the storm's organization, and by the time Dean crossed the Yucatán Peninsula it had weakened to a Category 1 hurricane.
Hurricane Dean emerged into the Bay of Campeche as a Category 1 hurricane on the afternoon of August 21. Its inner core was largely disrupted, so although a ragged eye reformed over the warm waters of the bay, the hurricane no longer had the structure to support its previous strength. Nevertheless, the warm waters of the bay proved conducive for some development and the eye contracted overnight, indicating that the hurricane was regaining structure. With better structure came stronger winds of 100 mph, and the storm was re-categorized as a Category 2 hurricane.
The storm's strengthening pattern continued until Hurricane Dean made its second and final landfall at 1630 UTC August 22 near Tecolutla, Veracruz, just east of Gutiérrez Zamora and about 40 mi south-southeast of Tuxpan. A weather station at Requetemu, San Luis Potosí, recorded 15.4 in of rainfall during the storm's second landfall. Dean weakened rapidly, losing its low level circulation within hours and its mid-level circulation the next day as it encountered the Sierra Madre Oriental mountain range. Its remnants passed over the mountains and into the eastern Pacific Ocean as a broad area of low pressure. Hurricane Dean's remnant low pressure system then drifted north into southern California, bringing thunderstorms to northern San Diego County, and more than 2 in of rain to Lake Wohlford. In Escondido almost 2 in of rain fell in 90 minutes. The remnant low pressure system weakened over western Arizona and southern California before finally dissipating on August 30.