Hurricane Opal was a large and powerful tropical cyclone that caused severe and extensive damage along the northern Gulf Coast of the United States in October 1995. The fifteenth named storm, ninth hurricane and strongest tropical cyclone of the unusually active 1995 Atlantic hurricane season, Opal developed from the interaction of a tropical wave and a low-pressure area near the Yucatán Peninsula on September 27 as Tropical Depression Seventeen. The depression crossed the Yucatán Peninsula and intensified into a tropical storm on September 30. Opal intensified into a hurricane on October 2 after entering the Gulf of Mexico. The cyclone turned northeastward and strengthened significantly. By October 4, Opal was an intense 150 mph (240 km/h), Category 4 hurricane. With a minimum pressure of 916 millibars (916 hPa; 27.0 inHg), Hurricane Opal was the most intense Category 4 Atlantic hurricane on record. However, the cyclone abruptly weakened to a low-end Category 3 hurricane prior to making landfall on the Florida Panhandle near Pensacola later that day. The storm quickly unraveled as it moved inland and became extratropical on October 5. The remnants of Opal moved northward and dissipated over Ontario the following day.
The precursor and initial stages of Opal brought heavy rainfall and flooding to Guatemala and Mexico. In the former, flooding and landslides left about 34,000 people homeless and damage to infrastructure and agriculture. A total of 31 deaths occurred in Guatemala. In Mexico, a number of rivers overflowed in the states of Campeche and Tabasco, forcing more than 42,000 people to evacuate. The storm left hundreds of millions of dollars in damage to agriculture in Campeche alone. Nineteen people were killed in the country. In Florida, high winds and storm surge left extensive damage in the panhandle. The majority of structures were swept away or experienced some degree of damage, particularly from Wakulla County westward. In Escambia, Okaloosa, Santa Rosa and Bay counties, nearly 300 homes were destroyed and 1,000 others suffered major damage. The storm left at least $2.1 billion in damage in Florida alone. Several other states were impacted by the storm, especially Alabama, where the storm spawned many tornadoes and strong winds downed numerous trees and left about 2.6 million people without electricity. A total of 13 deaths were attributed to Opal in the United States. The hurricane overall left about $4.7 billion in damage, much of which took place in the US. Due to its destructive effects, the name Opal was retired in the spring of 1996 and replaced with Olga for the 2001 season.
Meteorological history
The origins of Hurricane Opal were linked using satellite imagery and synoptic analyses to a tropical wave that left the western coast of Africa on September 11. Ten days later, the disturbance reached the Lesser Antilles after crossing the tropical Atlantic. Continuing westward, the disturbance showed little signs of organization before entering the western Caribbean Sea on September 23. There, the wave became entangled with a broad area of low-pressure east of Nicaragua, and the combined system drifted west-northwestward toward the Yucatán Peninsula; but even then, the disturbance lacked significant development. However, a burst of thunderstorm activity occurred near the storm's center on September 27, prompting the National Hurricane Center (NHC) to declare the system a tropical depression at 18:00 UTC that day. At the time, the depression was centered 80 mi (130 km) south-southeast of Cozumel, Mexico.
The primordial depression meandered across the Yucatán Peninsula during the three days following tropical cyclogenesis due to the lack of dominant steering currents. Despite remaining over land for an extended period, the depression developed organized rainbands, and ships in the region reported weather conditions that were suggestive of a stronger system. As a result, the NHC upgraded the disturbance to tropical storm intensity at 12:00 UTC on September 30 while the storm was over the north-central coast of Yucatán; this classification resulted in the tropical cyclone being named Opal, which also made it the first Atlantic storm to be given a name starting with the letter O. Over the next two days, Opal entered the Gulf of Mexico before tracking slowly west-southwestward into the Bay of Campeche. There, the storm strengthened into a hurricane at 12:00 UTC on October 2. Shortly afterward, a primitive eye began to form. At the same time, a strong trough tracking across the United States caused Opal to slowly turn northeastward.
After clearing the Bay of Campeche, Opal accelerated towards the United States Gulf Coast. The combination of warm sea surface temperatures associated with an unusually warm pocket of ocean waters and an upper-level high pressure area over the Gulf of Mexico resulted in a highly conducive environment for intensification. After a significant reorganization in Opal's internal structure, the hurricane was able to rapidly intensify in these favorable conditions. At 12:00 UTC on October 4, Opal reached peak intensity with maximum sustained winds of 150 mph (240 km/h), making it a Category 4 hurricane on the Saffir–Simpson hurricane wind scale, and a minimum barometric pressure of 916 hPa (27.05 inHg), a pressure typical for a Category 5 hurricane. The tropical cyclone's eye measured 12 mi (19 km) at peak intensity as the storm was beginning an eyewall replacement cycle. The progression of this cycle resulted in Opal's gradual weakening thereafter. At 22:00 UTC that day, Opal made landfall between Pensacola Beach, Florida and Navarre Beach, Florida, on a stretch of beach now known as "Opal Beach", as a weakened Category 3 hurricane with winds of 115 mph (185 km/h). Weakening quickened as Opal moved further inland, degenerating into a tropical depression over Tennessee less than a day after landfall. The diffusing cyclone transitioned into an extratropical cyclone shortly afterwards; these extratropical remnants tracked towards the northeast before they were last noted along the northern shore of Lake Ontario in Eastern Ontario.
Preparations
Although Opal was a weak system located over the Yucatán Peninsula at the time, 350 people evacuated from Grand Isle, Louisiana on September 28 after rough surf associated with the distant cyclone began to threaten Louisiana Highway 1—the only thoroughfare connecting Grand Isle with the Louisianan mainland. The following day, oil companies operating offshore oil drilling platforms in the Gulf of Mexico began evacuating workers from the rigs to land. On October 1, a coastal flood watch was issued for portions of the United States Coast due to the risk of storm surge from Opal. The United States Coast Guard issued an advisory for boaters in the Gulf of Mexico to use caution or remain in port where possible. The next day, the Galveston, Texas, emergency operations center opened to monitor the tropical cyclone and deliberate upon potential preparations for the city. Meanwhile, the launch Space Shuttle Columbia's STS-73 mission set for October 5 was postponed due to Opal's anticipated effects.
On October 3, a voluntary evacuation order was placed on Plaquemines Parish, Louisiana, due to the risks of potential storm surge. Schools were also closed by noon that day across the parish. Voluntary evacuation orders for the Florida panhandle, which would ultimately be the most heavily affected area, also began the same day with several counties giving evacuation orders. Farther west, a mandatory evacuation order was placed on Mobile County, Alabama, by then-Governor Fob James. Just before noon on October 4, with the hurricane near landfall, Escambia, Okaloosa and Santa Rosa counties halted evacuations, instead ordering those still within vulnerable areas to seek shelter instead. However, the large number of evacuees led to severe traffic congestion; Escambia County officials estimated that "tens of thousands" were still on evacuation routes within the county only a few hours before Opal made landfall. Mass evacuations in some other counties concluded during the afternoon of October 4, though many evacuees in other locations were unable to reach safe areas prior to the onset of gale-force winds.
An estimated 100,000 people evacuated from the United States Gulf Coast ahead of Opal, with 5 percent of evacuees seeking public shelters and over half of evacuees seeking shelter out of their home counties; in their post-storm assessment the Federal Emergency Management Agency (FEMA) noted that the landfalls of Hurricane Allison and Hurricane Erin on the Florida panhandle earlier in the year produced a dichotomous mood toward preparations for Hurricane Opal—some people may have taken a "wait and see" approach that resulted in complacency, while others affected by the widespread power outages caused by Erin may have acquired a greater sense of readiness toward the approaching hurricane. Regardless, the overall evacuation process was described as chaotic, and the failure to clear hurricane evacuation routes of casual or communal traffic was blamed for the relative unease during evacuations for Opal. Traffic congestion on these routes caused some evacuees to return to vulnerable areas along the coast while raising fears that stranded evacuees on highways could be subjected to potentially fatal hurricane-force winds.
The post-landfall watches and warnings released in accordance with Opal were a flash flood warning released on October 5 for portions of Alabama, northern Georgia, and the western parts of North Carolina and South Carolina. The warning also included eastern Tennessee. A flash flood watch was also in effect for portions of the Upper Ohio Valley, the Mid-Atlantic region, the central Appalachians, and the lower Great Lakes. Wind warnings were in effect for northwestern South Carolina all the way to western New York. A gale watch was also in effect for Lake Erie, Lake Ontario, and the southern sections of the St. Lawrence Seaway.
Six hours later, the gale warnings over Lake Erie, Lake Ontario, and the southern sections of the St. Lawrence Seaway were upgraded into a storm warning for Erie alone. The gale warning for the other two sections remained. The shoreline of Lake Erie was under a beach erosion warning from Buffalo, New York to Ripley, New York. The Storm Prediction Center released a tornado watch for northern and central New Jersey and portions of New York and Connecticut on October 6.
Significant non-surge areas of Escambia County, Florida, south of US 98 were included in evacuation areas because of the potential for isolation by flooding.
Impact
Mexico and Central America
As a tropical storm, Opal's slow movement led to prolonged, flooding rains over the Yucatán, killed 19 people in Mexico and another 31 in Guatemala. Tabasco received about 20% of its annual rainfall in four days. Across Campeche and Tabasco, more than 42,000 people were forced to evacuate as rivers overflowed their banks. According to Notimex, approximately 100,000 people evacuated due to the storm. By October 1, an estimated 500,000 acres of crops had been destroyed by the floods. In San Francisco de Campeche, flood waters reached a depth of 6 ft (1.8 m). Governor Jorge Salomon ordered the closure of all government offices, businesses, and schools by October 2 in light of the extensive flooding. At least 60 towns across the state were isolated by the extreme rainfall. By October 3, agricultural losses in Campeche alone were estimated in the billions of pesos (hundreds of millions of USD).
United States
Throughout the United States, Opal killed 13 people. Monetary damage totaled about US$4.7 billion (1995 dollars) in damage. This made Opal the country's third-costliest Atlantic hurricane at the time. Opal also produced an outbreak of 22 tornadoes across the southeastern United States.
Florida
Opal's storm surge affected the Florida panhandle coastline, estimated between 8 to 15 ft (2.4 to 4.6 m). The Panama City Beach pier recorded the highest observed surge, which was 8.3 ft (2.5 m) above sea level. High tides occurred as far east as Sarasota, which observed a 2 to 4 ft (0.61 to 1.22 m) storm surge. Rainfall in the state peaked at 15.52 in (394 mm) in Milton. The highest wind gust was 144 mph (231 km/h), recorded at Hurlburt Field, and the same station recorded sustained winds of 84 mph (135 km/h).
Most of the structural damage occurred near the coastline on the Florida Panhandle, due to intense surge. Nearly a mile of U.S. Highway 98 near Eglin Air Force Base was completely destroyed. The pavement was nearly replaced by mounds of sand left behind after storm surge. Opal also spawned an F2 tornado that killed a young woman in Florida. None died as a direct result of storm surge. This was quite unusual, considering the strength and landfall location of Opal. Okaloosa Island, Fort Walton Beach, was overwhelmed by storm surge. Numerous homes were under 3 to 10 feet (0.91 to 3.05 m) of water. Residents were not allowed to return to the island until the homes could be secured. A Humvee tour was arranged by the National Guard so home owners could 'see' the damage, but the homeowners were not allowed off the bus. Sand dunes along the stretch of US 98, normally 25 feet (7.6 m) high, were removed by wind and surge. Where once the ocean was obscured from view by the dunes for miles, a flat open space opened up along U.S. Highway 98.
Southeastern United States
The peak rainfall from Opal in Alabama was 19.42 inches (493 mm) 3 miles (4.8 km) east-northeast of Brewton, Alabama. Lesser amounts include 7.48 inches (190 mm) in Mobile and 6.1 inches (150 mm) in Anniston. The highest gust reported was a 95 mph (153 km/h) gust in Fort Rucker and a secondary one at Maxwell Air Force Base with a gust of 90 mph (140 km/h). The highest sustained winds reported from Opal was 75 mph (121 km/h) at Fort Rucker, 55 mph (89 km/h) in downtown Mobile and 47 mph (76 km/h) at Maxwell Air Force Base and Montgomery. Numerous downed trees across much of the southeastern United States left over 2 million people without power. Alabama reported that 476,000 residents were without power, which was a record at the time; however, this number was surpassed by Hurricane Ivan in 2004. Damage was heavy far inland, all the way to Montgomery, where sustained winds reached 90 mph (140 km/h).