Hurricane Danielle (2022)

Hurricane Danielle (also known as Ex-Hurricane Danielle in Europe) was a high-latitude Category 1 hurricane that persisted over the central Atlantic Ocean for nearly two weeks. The fourth named storm, and first hurricane of the 2022 Atlantic hurricane season, and the first windstorm of the 2022–23 European windstorm season, its formation ended an almost two-month-long period of tropical cyclone inactivity in the Atlantic basin.

Danielle remained over the open ocean as a tropical cyclone before dissipating off the coast of Portugal as an extratropical cyclone. The Azores and much of Portugal received heavy rain from the system. Overall, damage from Danielle was moderate.

Meteorological history

On August 31, an area of low pressure formed along a decaying frontal zone over the central subtropical Atlantic. The disturbance quickly developed into Tropical Depression Five by 06:00 UTC on September 1, about southeast of Cape Race, Newfoundland, and then strengthened into Tropical Storm Danielle six hours later. Benefiting from abnormally warm sea surface temperatures and light wind shear, Danielle became a hurricane around 12:00 UTC on September 2, about west of Flores Island in the Azores. Later that day, the system slowed to nearly stationary as it was caught south of a blocking high, causing it to weaken back into a tropical storm by 06:00 UTC on September 3, due upwelled cooler waters. Later, Danielle drifted westward, escaping its cold wake. This move enabled the storm to re-strengthen into a Category 1 hurricane. Now moving through relatively warm ocean waters and experiencing low shear, Danielle attained peak sustained winds of by 18:00 UTC on September 4, while located about west of Flores Island. Danielle moved northeastward for the next few days, weakening and at times barely maintaining hurricane intensity, before rebounding slightly on September 7, when it attained a minimum pressure of .

Deep-layer shear increased late that day, causing Danielle to weaken to a tropical storm by 06:00 UTC on September 8. Six hous later, when located about north of Flores Island, the storm transitioned into an extratropical cyclone. From then through September 10, the cyclone made a counterclockwise loop over the open ocean while interacting with a deep-layer low moving eastward from Atlantic Canada. It then moved eastward and southeastward while gradually weakening, and made a series of slow loops near the coasts of Portugal and northwestern Spain, before dissipating about north-northwest of Lisbon, Portugal, late on September 15.

Preparations and impact

Large waves and heavy rain hit the Azores. Extratropical Danielle brought heavy rain to mainland Portugal. Between September 12–13, 644 accidents were reported throughout the country. Many downed trees and flash floods were reported. In Manteigas, floods and landslides caused major damage. Four vehicles were pulled into the Zêzere River. The municipality was under a "state of calamity" at the time, following intense summer forest fires in nearby areas of the Serra da Estrela mountain range, compounding the situation. Heavy rain extended to as far north as Braga. Covilhã saw of rain while Viseu saw of rain. Minor wind and flooding damage was reported in both Lisbon and Setúbal. One man was in serious condition when he was swept away and was under cardiac arrest. The mayor of Manteigas, Flavio Massano, stated that the damage was severe, quoting "Several vehicles were swept away by the force of the water, there are houses and businesses affected, roads, public lighting, water and sanitation infrastructures, sports and recreational equipment, among others". The Grândola Police Station had severe roof damage after Danielle hit. Civil Protection reported 380 emergency calls, and later on September 14, the number of calls had doubled. Yellow rainfall warnings were issued throughout Portugal due to Danielle. Many locations were hit by flooding, covering numerous roadways and damaging several bridges.

See also

* Weather of 2022
* Tropical cyclones in 2022
* Timeline of the 2022 Atlantic hurricane season
* Other tropical cyclones named Danielle
* List of Azores hurricanes
* Tropical cyclone effects in Europe – Other former tropical storms that have affected Europe
* Hurricane Nadine (2012) – followed an erratic hurricane and produced hurricane-force gusts to parts of the Azores
* Hurricane Pablo (2019) – a Category 1 hurricane which took an identical track to Danielle until it curved northward

References

{{2022 Atlantic hurricane season buttons

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2022 in Portugal
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September 2022 events in Portugal
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