Hurricane Dolly (2008) - Meteorological History

Meteorological History

An area of disturbed weather formed over the tropical Atlantic about 1600 miles (2600 km) east of the southern Windward Islands on July 13 in association with a strong tropical wave. The wave tracked across the Caribbean Sea during the third week of July. Despite producing strong convection and tropical storm-force sustained winds, it failed to develop a low-level circulation until July 20. That morning, reconnaissance aircraft found a low-level circulation and the system was identified as a tropical cyclone by the National Hurricane Center (NHC). The reconnaissance data showed that the storm had maximum sustained winds exceeding the 34-knot (39 mph; 63 km/h) threshold for tropical storm status. Additionally, buoy data corroborated that the system was producing speeds of this velocity at sea level, so the NHC declared the system to be a tropical storm—bypassing the tropical depression stage altogether—and giving it the name Dolly.

At this point, Dolly was located 270 mi (435 km) east of Chetumal, and 230 mi (365 km) southeast of Cozumel; the tropical storm was expected to make landfall later that day. At the time of Dolly's approach to Quintana Roo, 100,000 tourists were in the state, and 45,000 of them in Cancún. Originally, the storm was forecast by the Servicio Meteorológico Nacional (Mexico's national weather service) to make landfall between Playa del Carmen and Tulum. However, as the storm approached the Quintana Roo coastline, it lost its organization and its surface circulation center disappeared. When the storm was just offshore, it began reorganizing, and a new circulation center formed in the heavy convection on the northern sector of the storm. In essence, this caused the storm to briefly move parallel to the coastline, shifting the point of Dolly's first landfall to north of Cancún. The northward shift also caused the bulk of the storm to stay over water, reducing its impact on the Yucatán Peninsula.

After moving into the Gulf of Mexico, weather conditions became favorable for additional intensification, with low wind shear and warm sea surface temperatures. Dolly strengthened steadily beginning on July 21, and by the afternoon of July 22, it strengthened into a Category 1 hurricane on the Saffir-Simpson Hurricane Scale. At this point, the storm was located about 165 mi (265 km) east-southeast of Brownsville, Texas. Steady strengthening continued that evening and into the morning of July 23, at which point Dolly reached Category 2 intensity while just east of the Rio Grande Valley at 10:00 that morning with winds of up to 100 mph (160 km/h) and a minimum central pressure of 963 mbar. At 1:00 pm CDT (1800 UTC) that same day, Dolly made landfall on South Padre Island, Texas, slightly weaker as a Category 1 hurricane with 85 mph (140 km/h) sustained winds and a pressure of 967 mbar. Hurricane Dolly then moved west-northwestward over the Laguna Madre crossing onto the mainland near the Cameron-Willacy County line. South Padre Island, Port Isabel, Laguna Vista, Los Fresnos, Bayview, Brownsville, San Benito, Rio Hondo, Arroyo City and especially Harlingen suffered heavy wind and flooding. Hurricane Dolly then thrashed the Delta Region along and north of Highway 107 with its most fierce winds and rain. Towns like Santa Rosa, La Villa, Edcouch, Elsa, Monte Alto and San Carlos were hit hard by the slow-moving, wet hurricane which dumped 10-20 inch rains. According to Mid Valley Town-Crier newspaper, the Weslaco Airport clocked gusts of 68 knots (78 mph). Dolly weakened to a tropical storm after passing US 281 (west of San Manuel and Linn, Texas) late on the 23rd, and then a tropical depression, as it moved slowly inland into Mexico. The circulation weakened into a remnant low over northern Mexico on the afternoon of July 25, then crossed back into the United States, passing through the Ciudad Juárez, Chihuahua/El Paso, Texas metropolitan area on the morning of July 26 and then north across New Mexico. The remnant low of Dolly finally began to dissipate late in the evening of July 27 approximately 100 km (62 mi) west-northwest of Dalhart, Texas.