Hurricane Delta
Hurricane Delta was a destructive tropical cyclone that became the record-tying fourth named storm of 2020 to make landfall in Louisiana, as well as the record-breaking tenth named storm to strike the United States in that year. The twenty-sixth tropical cyclone, twenty-fifth named storm, tenth hurricane, and third major hurricane of the record-breaking 2020 Atlantic hurricane season, Delta formed from a tropical wave which was first monitored by the National Hurricane Center on October 1. Moving westward, the tropical wave began to quickly organize. A well-defined center of circulation formed with sufficiently organized deep convection on October 4, and was designated as Tropical Depression Twenty-six and soon thereafter, Tropical Storm Delta. Extremely rapid intensification ensued throughout October 5 into October 6, with Delta becoming a Category 4 hurricane within 28 hours of attaining tropical storm status. The rate of intensification was the fastest in the Atlantic basin since Hurricane Wilma in 2005. After peaking in intensity however, an unexpected increase in wind shear and dry air quickly weakened the small storm before it made landfall in Puerto Morelos, Mexico as a Category 2 hurricane with winds. It weakened some more over land before emerging into the Gulf of Mexico, where it was downgraded to a Category 1 hurricane. After that, it began to restrengthen, regaining Category 3 status late on October 8. It then turned northward and reached a secondary peak intensity of and winds of 120 mph early on October 9. Delta then began to turn more north-northeastward into an area of cooler waters, higher wind shear, and dry air, causing it to weaken back to Category 2 status. Delta then made landfall at 23:00 UTC near Creole, Louisiana with winds of and a pressure of. The storm began to weaken more rapidly after landfall, becoming post-tropical just 22 hours later.
Widespread tropical cyclone watches and warnings were issued throughout the Western Caribbean and the Mexican states of Yucatán and Quintana Roo, which had just been hit by Hurricane Gamma, in preparation for the storm. As Delta moved out of the Gulf of Mexico, more watches were issued for the U.S. Gulf Coast, an area that had already seen multiple strong hurricanes such as Laura and Sally earlier in the season. States of emergency were also declared in the U.S. states of Louisiana, Mississippi, and Alabama and several coastal and low-lying areas were ordered to evacuate. In Mexico, trees and power lines were blown down, and roofs were ripped off homes and other buildings. Louisiana and Southeast Texas were again affected by heavy rain, high winds, and storm surge, and 14 weak tornadoes were confirmed in Mississippi, Alabama, Georgia and the Carolinas. Total insured losses resulting from the storm amounted to $3.09 billion, with $2.9 billion in the US and US$186 million in Mexico.
Meteorological history
Hurricane Delta originated from a tropical wave that departed off the west coast of Africa on September 26, 2020. It lacked deep atmospheric convection as it trekked across the tropical eastern Atlantic. With time, showers and thunderstorms began to increase within the wave, although no distinct circulation center was detected. Early on October 1, the National Hurricane Center began to monitor the tropical wave moving into the Eastern Caribbean for potential tropical cyclogenesis. As the system moved across the Lesser Antilles, thunderstorm activity fluctuated, inhibited from development by moderate vertical wind shear and dry air intrusion. At 18:00 UTC on October 4, analysis of satellite imagery and scatterometer data found a well-defined circulation center sustaining sufficiently-organized deep convection, marking the formation of Tropical Depression Twenty-Six about south of Kingston, Jamaica. Convection continued to increase after formation, but was initially confined to the southern portion of the circulation due to northerly wind shear. Once the shear lessened on October 5, convection became more symmetric around the center, and the system strengthened to become Tropical Storm Delta by 12:00 UTC that day about south-southwest of Montego Bay, Jamaica.While accelerating west-northwestward over the Western Caribbean along a building subtropical ridge to its north and northeast, Delta commenced a phase of rapid intensification over ideal environmental conditions encompassing warm seas, low wind shear, and high levels of moisture aloft, becoming a Category 1 hurricane 12 hours after being named. As it finally began to turn northwestward early on October 6, Delta reached Category 2 status just nine hours later at 09:00 UTC, before becoming a Category 3 major hurricane three hours later at 12:00 UTC. Delta's intensification was described as the fastest in a 24-hour period since Hurricane Wilma of 2005. The storm was characterized as a very symmetric and compact system as a pinhole eye began to form. At 15:20 UTC, an NOAA hurricane Hunter aircraft indicated that the storm's 1-minute sustained wind speed was at, making Delta a Category 4 hurricane. Delta intensified from a tropical depression to Category 4 hurricane in just over 36 hours, breaking the record of 42 hours that Hurricane Keith set in 2000. Measured at in width, the eye was slightly larger than the smallest eye ever observed in Hurricane Wilma in 2005.
Delta attained its peak intensity by 18:00 UTC with maximum sustained winds of and a barometric pressure of. Delta had intensified by in over 36 hours, which only four other tropical cyclones had been able to achieve since the satellite era. At this time, Delta exhibited its pinhole eye surrounded by very intense deep convection. Its pressure was unusually high for a storm this strong, which indicated that Delta's circulation did not extend as far into the upper troposphere as would be expected for a storm of its intensity. Additionally, the storm's eye was barely visible on visible satellite imagery, although it was seen on microwave images. Delta did not keep this intensity for very long as an increase in mid-level wind shear and dry air entrainment significantly disrupted Delta's small core, and the storm abruptly weakened with its banding features becoming less defined and its eye completely disappearing. The storm accelerated northwestward and at around 05:45 UTC on October 7, made landfall at Puerto Morelos, Quintana Roo, Mexico, as a high-end Category 2 storm with winds of. It subsequently weakened some more as it moved over the Yucatán Peninsula and into the Gulf of Mexico as a Category 1 hurricane. The storm remained well-organized throughout its passage over the peninsula, situating over conducive atmospheric and oceanic conditions; as such, Delta again intensified.
Satellite imagery revealed a central dense overcast as the system gradually intensifies into a Category 2 hurricane at 06:00 UTC of October 8. Delta steadily became more organized, with an eye occasionally becoming evident on satellite imagery and a lowering minimum central pressure as it turned northward ahead of an approaching trough to its northwest. Delta regained Category 3 status by 18:00 UTC about south of the Texas–Louisiana border. Early on October 9, Delta attained its secondary peak intensity with sustained winds of and a central pressure of. The storm held the intensity overnight until an increase of southwesterly wind shear and a decrease in ocean heat weakened it over the northern Gulf of Mexico into a Category 2 hurricane at 18:00 UTC. As an asymmetrical storm, Delta made another landfall near Creole, Louisiana at 23:00 UTC with winds of. After that, Delta began to weaken more rapidly, dropping to Category 1 status an hour after landfall at 00:00 UTC on October 10 and a tropical storm six hours later. It accelerated northeastward and transitioned into an extratropical cyclone over Western Mississippi by 18:00 UTC. The system continued to weaken and its circulation broadened through the day on October 11, and by 00:00 on October 12, it opened into a trough of low pressure over the southeastern United States.
Preparations
Cayman Islands and Cuba
were issued for the islands of Grand Cayman and Cayman Brac when advisories were first initiated on Potential Tropical Cyclone Twenty-Six. In the Cayman Islands, all public schools were closed from October 5 to October 6 as the rainbands were forecast to bring high winds and flooding to the islands. All government offices were on the afternoon of October 5 and remained closed for the entire day on October 6. Cayman Airways reported cancellation of its flights. The Red Cross shelter on Huldah Avenue was on stand-by in the event of flooding. The government set up facilities for shelter with proper protocol for COVID-19 for people with the virus isolating at home. All Government events on October 5–6 were cancelled, including Older Person's Month activities.When the initial advisory was issued for Potential Tropical Cyclone Twenty-Six, a hurricane watch was issued for the provinces Pinar del Río, Artemisa and the Isle of Youth while a tropical storm watch was issued for La Habana. Three hours after the storm was upgraded to Tropical Storm Delta, the watch for Pinar del Río was upgraded to a hurricane warning while a Tropical Storm Warning was issued for the Isle of Youth. This, however, was downgraded to a tropical storm warning when Hurricane Delta jogged south and put less of the area in harm's way.