Hurricane Teddy

Hurricane Teddy was a large and powerful Cape Verde hurricane that was the fifth-largest Atlantic hurricane by diameter of gale and Atlantic Canada in September 2020. The twentieth tropical depression, nineteenth named storm, eighth hurricane, and second major hurricane of the record-breaking 2020 Atlantic hurricane season, Teddy initially formed from a tropical depression that developed from a tropical wave on September 12. Initially, the depression's large size and moderate wind shear kept it from organizing, but it eventually intensified into ''Tropical Storm Teddy'' on September 14. After steadily intensifying for about a day, the storm rapidly became a Category 2 hurricane on September 16 before westerly wind shear caused a temporary pause in the intensification trend. It then rapidly intensified again on September 17 and became a Category 4 hurricane. Internal fluctuations and eyewall replacement cycles then caused the storm to fluctuate in intensity before it weakened some as it approached Bermuda. After passing east of the island as a Category 1 hurricane on September 21, Teddy restrengthened back to Category 2 strength due to baroclinic forcing. It weakened again to Category 1 strength the next day before becoming post-tropical as it approached Atlantic Canada early on September 23. It then weakened to a gale-force low and made landfall in Nova Scotia with sustained winds of . The system weakened further as it moved northward across eastern Nova Scotia and then the Gulf of St. Lawrence, before being absorbed by a larger non-tropical low early on September 24, near eastern Labrador.

Tropical storm watches and warnings were issued for both Bermuda and Atlantic Canada in preparation for Teddy. Its large size and strength caused high waves and rip currents to impact areas hundreds of miles from its path, ranging from the Lesser and Greater Antilles to the East Coast of the United States and Atlantic Canada. Two people in Puerto Rico drowned from the strong waves while another drowned in New Jersey. Total damage is estimated to be at least $35 million.

Meteorological history

The National Hurricane Center (NHC) began to monitor a tropical wave over West Africa early on September 7. The wave moved over the Atlantic Ocean on September 10, accompanied by a large area of deep convection, and began to steadily organize, forming a broad low-pressure area over the following day. Though the wave was experiencing moderate northeasterly shear, convection increased early on September 12, which led to the development of a well-defined surface center and the formation of ''Tropical Depression Twenty'' around 06:00 UTC while the system was located about southwest of the Cabo Verde Islands.

Initially, the depression struggled to organize, due to its large size and moderate wind shear. After the shear decreased, the depression became better organized and became ''Tropical Storm Teddy'' near 00:00 UTC on September 14. It was the earliest-forming 19th tropical or subtropical storm on record in an Atlantic hurricane season, surpassing the old mark of October 4, set by the unnamed "Azores" subtropical storm in 2005. Teddy continued to intensify as it became better organized, with an eye beginning to form late on September 15. By 00:00 UTC, September 16, Teddy strengthened to become a category 1 hurricane while located about east-northeast of Barbados. The storm continued to intensify, becoming a category 2 hurricane later that day. Some slight westerly wind shear briefly halted further intensification, but when it subsided, the storm began another period of rapid intensification early on September 17. Teddy strengthened into a major category 3 hurricane near 12:00 UTC while centered about east-northeast of Guadeloupe, and to category 4 strength three hours later. Late that Day, Teddy reached its peak intensity with maximum sustained winds of a minimum barometric pressure of . On September 18, an eyewall replacement cycle caused the storm to weaken slightly to category 3; and the following day, an increase in southwesterly shear caused it to drop below major hurricane strength around 00:00 UTC on September 20. Teddy then moved over slightly cooler waters caused by upwelling from Hurricane Paulette, contributing to its weakening trend.

Teddy passed about east of Bermuda on September 21 as it turned northward and north-northeastward while interacting with a negatively tilted trough. This interaction caused an increase in both the storm's maximum wind speed and size. Teddy reached a secondary peak intensity of between 06:00 UTC and 12:00 UTC on September 22. Interaction with the trough also triggered the extratropical transition process; Teddy's wind field became more asymmetric, and the associated convection become less centralized. At about 18:00 UTC that same day, the hurricane weakened to Category 1 intensity, before becoming an extratropical low at around 00:00 UTC on September 23, while located about south of Halifax, Nova Scotia. Just before this transition, the diameter of gale-force winds measured up to across from northeast to southwest, making Teddy the 4th largest Atlantic hurricane on record.

At 12:00 UTC on September 23, the storm made landfall near Ecum Secum, Nova Scotia, with sustained winds of . The storm weakened as it moved northward across eastern Nova Scotia and then the Gulf of St. Lawrence, where it was absorbed by a larger non-tropical low early on September 24, near eastern Labrador. This low, fueled by Teddy's remnant energy, accelerated northward, before proceeding to make a counterclockwise loop over the Labrador Sea for the next couple of days, briefly strengthening back into a hurricane-force low, before weakening again. Afterward, it slowly drifted eastward, before being absorbed into another larger storm near Iceland on September 29.

Preparations and impact

Large swells were generated by the storm, which affected the Lesser Antilles, the East Coast of the United States, Bermuda, and Atlantic Canada. One buoy operated by the National Oceanic and Atmospheric Administration (NOAA) in the open northern Atlantic off the coast of Nova Scotia reported a wave height of early on September 22. Another wave height of was reported later in the day by the same buoy. Waves reached at another buoy just north of Teddy on the afternoon of September 22, with winds gusting near .

Bermuda

Tropical storm watches, which were later upgraded to warnings, were issued for Bermuda due to the impacts expected from Teddy. The Government of Bermuda shut down the island on September 21, closing all government services such as public transportation and schools. The L.F. Wade International Airport was closed during the storm, but reopened on September 22 after the storm passed. 220 homes lost power on the island, mainly in Hamilton and Pembroke parishes. Beach erosion was also reported.

United States

The National Weather Service warned of high winds and coastal flooding in eastern New England. A high wind warning was issued for Nantucket and coastal Plymouth County on September 22. In addition, a high surf advisory was issued for those areas and for Bristol County. A wind advisory was issued for other coastal communities on mainland Massachusetts. For all of Massachusetts, a Red Flag warning was issued, signaling that critical fire weather conditions were possible due dry weather and gusty winds. In North Carolina, a coastal flood warning was in effect for the Northern Outer Banks and Hatteras Island until September 21, but minor coastal flooding was forecasted by the National Weather Service until September 22. A coastal flood advisory was extended to for Pamlico, Southern Craven, Carteret and coastal Oslow counties as well as Ocracoke Island