Hurricane Isaias
Hurricane Isaias was a destructive tropical cyclone that caused extensive damage across the Caribbean and the East Coast of the United States while also giving rise to the strongest tropical cyclone-spawned tornado since Hurricane Rita in 2005. The ninth named storm and second hurricane of the extremely active and record-breaking 2020 Atlantic hurricane season, Isaias originated from a vigorous tropical wave off the coast of Africa that was first identified by the National Hurricane Center on July 23. The tropical wave gradually became more organized and obtained gale-force winds on July 28 before organizing into Tropical Storm Isaias on July 30. Isaias marked the earliest ninth named storm on record, surpassing 2005's Hurricane Irene by eight days. Isaias strengthened into a Category 1 hurricane on the next day, reaching an initial peak of, with a minimum central pressure of 987 mbar. On August 1, the storm made landfall on North Andros, Bahamas and subsequently weakened to a tropical storm, before paralleling the east coast of Florida and Georgia. As Isaias approached the Carolina coastline, it reintensified back into a hurricane. Soon afterward, Isaias reached its peak intensity, with maximum 1-minute sustained winds of 90 mph and a minimum central pressure of, before making landfall near Ocean Isle Beach, North Carolina, at 03:10 UTC on August 4, at the same intensity. The storm proceeded to accelerate up the East Coast of the United States as a strong tropical storm, before transitioning into an extratropical cyclone over Quebec on August 4. Isaias's extratropical remnants persisted for another day, before dissipating on August 5.
Numerous tropical storm watches and warnings as well as hurricane watches and hurricane warnings were issued for the Lesser Antilles, Greater Antilles, Bahamas, Cuba, and the East Coast of the United States. Isaias impacted portions of the Eastern Caribbean and caused significant damage in the Eastern United States. Devastating flooding and wind damage were reported in Puerto Rico and the Dominican Republic, with many towns without electricity or drinking water. Trees were uprooted and power lines were downed in much of the Eastern United States from both damaging winds and tornadoes, with more than 3 million power outages reported, nearly half of them in New Jersey. Isaias was also the second tropical cyclone to affect the Northeastern States in 3 weeks after Tropical Storm Fay in early July. Many people were without power for days after the storm in New York and Connecticut, leading to investigations into power and electricity companies. There were 17 storm-related deaths : 14 in the contiguous United States, two in the Dominican Republic, and one in Puerto Rico. Overall, Isaias caused approximately $5.025 billion in damage, with $4.8 billion in damage occurring in the U.S. alone, making Isaias the costliest tropical cyclone to affect the Northeastern United States since Hurricane Sandy in 2012. The Spanish name Isaias was found by many people to be difficult to enunciate, and was mispronounced by some weather forecasters in the United States. Isaias was one of several destructive 2020 hurricanes whose names were not retired following the season by the World Meteorological Organization, along with: Sally, Delta, and Zeta.
Meteorological history
The National Hurricane Center first began tracking a vigorous tropical wave off the west coast of Africa on July 23. The wave gradually organized and became better defined, developing a broad area of low pressure on July 25. Though the circulation was broad and disorganized, convection continued to increase over the system, and the system obtained gale-force winds on July 28. Although the system still lacked a well-defined center, an imminent threat of tropical cyclogenesis and tropical storm-force winds to land areas prompted its designation as Potential Tropical Cyclone Nine at 15:00 UTC on July 28. The system moved just south of Dominica on July 29, and at 03:00 UTC on the following day, the system organized sufficiently to become a tropical cyclone. Due to its precursor disturbance already having gale-force winds, it was immediately declared a tropical storm and given the name Isaias. When Tropical Storm Isaias developed, it became the earliest ninth named storm on record, breaking the record of Hurricane Irene in 2005 by eight days. Isaias continued strengthening after reaching tropical storm status, with 1-minute sustained winds reaching on July 30 as it made landfall on the southern coast of the Dominican Republic. Contrary to predictions by meteorologists, the mountainous terrain of Hispaniola did not weaken the storm as the system had a broad circulation and developed a new low-pressure center to the north of the island, allowing Isaias to maintain its intensity.Early the next day, hurricane hunters unexpectedly found that Isaias had strengthened into a hurricane. After fluctuating between for 18 hours, Isaias reached its initial peak intensity with, 1-minute sustained winds of and a minimum central pressure of. Moderate to strong southwesterly wind shear and dry air entrainment began affecting the storm a few hours later, resulting in the low-level circulation center being exposed near the western edge of the convection. After a brief weakening trend, Isaias began to intensify again, with deep convection firing over the exposed center and an eye feature forming, as seen on Bahamian radar. Later that evening, data from another hurricane hunter reconnaissance aircraft confirmed a closed eyewall and a lower minimal central pressure of. The storm strengthened afterwards to reach another peak, with 1-minute sustained winds of, despite a somewhat ragged appearance on satellite imagery. At 15:00 UTC on August 1, Isaias made landfall on Northern Andros Island, Bahamas with sustained winds of, slightly weaker than its peak. Land interaction and the continued effects of wind shear and dry air continued to weaken the system, and Isaias dropped below hurricane strength at 21:00 UTC, as its center became completely devoid of convection, although a large burst of convection formed over the center shortly after it moved back over water.
As the storm approached South Florida, a strong mid-level circulation formed just northeast of the storm's low-level circulation center, spawning intense convection mainly north and east of the LLCC. The storm then paralleled the east coast of Florida and Georgia, with its winds fluctuating between. As the storm turned northeastward, it entered a more favorable environment for strengthening, with wind shear relaxing just enough to allow the storm to redevelop intense convection. The storm began to quickly reintensify, regaining hurricane status at 18:00 UTC on August 3, before reaching its peak intensity, with 1-minute sustained winds of and a minimum central pressure of. At 03:10 UTC on August 4, the hurricane made landfall near Ocean Isle Beach, North Carolina at the same intensity. With its landfall, Isaias became the earliest fifth named storm to make landfall in the United States. The previous record for the earliest fifth storm to make a U.S. landfall was August 18, set during the 1916 season. Following landfall, Isaias continued to accelerate and only weakened slowly, dropping below hurricane status at 07:00 UTC over North Carolina. Isaias moved quickly to the north-northeast, crossing through Virginia, Maryland, Pennsylvania, New Jersey, and then into New York. The system lost tropical characteristics as it merged with a cold front to the west, becoming extratropical at 03:00 UTC on August 5, over southern Quebec, east-southeast of Montreal, with the NHC discontinuing advisories on the storm at 09:00 UTC. Afterward, Isaias's extratropical remnant moved northwestward, before turning eastward on August 6. Later that day, Isaias's low-pressure center split into two separate lows, with the newer low to the east absorbing the original low shortly afterward.
Preparations
Numerous tropical storm, hurricane, and storm surge watches and warnings were issued for areas in the path of Isaias.Antillean Islands
The first tropical storm watches and warnings were posted for Puerto Rico, the Virgin Islands, the Leeward Islands, the Dominican Republic, and Haiti when the system was designated Potential Tropical Cyclone Nine.Bahamas
With the system approaching and strengthening, hurricane warnings were posted for the Northwestern Bahamas at 00:00 UTC on July 31. The sudden upgrade to hurricane status caused all of the Bahamas to go under a hurricane warning at 03:40 UTC.People living on Abaco and Grand Bahama islands were evacuated before the storm. Many of the citizens were still living in temporary structures due to damage caused by Hurricane Dorian in 2019. Many of the structures were weak and could be easily destroyed by tropical storm and hurricane-force winds. The meteorology department of the Bahamas advised citizens to "hunker down". The government of the Bahamas lifted the COVID-19 lockdown instituted for controlling the virus before the storm so people could freely travel to safer places. Shelters were opened on larger islands in the island chain, with people on smaller, less populated, islands needing to travel to reach a shelter. Bahamas Power and Light shut off electricity to areas at high risk of flooding on New Providence, the most populous island in the Bahamas, until it was safe to re-energize.
United States
Once Isaias made landfall late on August 3, several airlines issued flight waivers for flights involving East Coast airports.Southeast
Tropical storm watches were first initiated in South Florida at 21:00 UTC on July 30, with more watches and warnings going up as the storm got closer. Hurricane warnings were issued as the storm approached, but they were downgraded to tropical storm warnings when the storm weakened. Hurricane warnings were issued for areas near the South Carolina–North Carolina border after the storm was forecasted to reach minimal hurricane status again just before landfall. At one point, tropical storm watches and warnings extended over 1,000 miles from Florida to Maine. Tornado watches were also issued in Northeastern South Carolina and Eastern North Carolina.In anticipation of the storm, the state of Florida closed COVID-19 testing sites on July 30 due to potential impacts from Isaias. The next day, Florida governor Ron DeSantis declared a state of emergency for the eastern coast of Florida ahead of Isaias. Both Biscayne National Park and the Everglades National Park closed in preparation for Hurricane Isaias, although Dry Tortugas National Park remained open.
In Georgia, beaches were closed and the Coast Health District suspended all operations. The Sidney Lanier Bridge in Glynn County was closed at 6 a.m. on August 3 as the storm approached. Savannah's Talmadge Memorial Bridge was also scheduled to close at 2 p.m. that day, but remained open. Inspections were planned for both bridges after the storm passed. Cumberland Island National Seashore was closed in preparation of the storm as well.
On July 31, North Carolina governor Roy Cooper declared a state of emergency ahead of the storm. A mandatory evacuation of Ocracoke Island, North Carolina, was issued that same day. Both Cape Lookout National Seashore and Cape Hatteras National Seashore closed ahead of the hurricane on August 1.