5,021 articles
Current meter
A current meter is an instrument for measuring the velocity of water at a point in an open channel, used to compute river discharge by the velocity-area method.
Curve number method
The curve number method is an empirical hydrological technique that estimates direct runoff depth from storm rainfall on a watershed using a single parameter, the curve number.
Cut-off grade
A cut-off grade is the grade, or metal concentration in rock, that decides whether mined material is treated as waste or sent to a processing facility, defining ore.
Cut-off low
A cut-off low is a closed cold low-pressure system in the upper troposphere that breaks away from the jet stream, lingers for days, and often causes heavy rainfall and flooding.
Cyclone
A cyclone is a rotating low-pressure weather system with winds circling a low-pressure center, spinning anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Cyclone Aila
Cyclone Aila was a severe cyclonic storm that struck the West Bengal coast of India and south-western Bangladesh in May 2009, killing about 300 people and affecting millions.
Cyclone Alfred
Severe Tropical Cyclone Alfred was a 2025 Coral Sea cyclone that struck southeast Queensland and northern New South Wales, causing about $1.36 billion in damage and one death.
Cyclone Amphan
Cyclone Amphan (Thai: อัมพาน) was a powerful tropical cyclone that hit West Bengal, India, and Bangladesh in May 2020, causing about $14 billion in losses.
Cyclone Chido
Cyclone Chido was an intense tropical cyclone of the 2024–2025 season that struck Mayotte on 14 December 2024 with gusts over 220 km/h, then hit Mozambique.
Cyclone Ditwah
Cyclone Ditwah, officially Cyclonic Storm Ditwah, was a tropical cyclone that struck Sri Lanka in late November 2025, causing the country's deadliest cyclone disaster since 2004.
Cyclone Eline
Cyclone Eline, first named Severe Tropical Cyclone Leon, was a long-lived February 2000 cyclone that crossed the Indian Ocean, struck Madagascar and Mozambique, and contributed to devastating floods.
Cyclone Eloise
Tropical Cyclone Eloise was a tropical cyclone of the 2020–21 South-West Indian Ocean season that struck near Beira, Mozambique, in January 2021, killing at least 15 people.
Cyclone Fani
Cyclone Fani was an extremely severe cyclonic storm that struck Puri, Odisha, on 3 May 2019, prompting the evacuation of over 1.4 million people in Odisha.
Cyclone Freddy
Cyclone Freddy was a long-lived tropical cyclone of the 2022–23 South Indian Ocean season that struck Madagascar, Mozambique, and Malawi and set the world duration record.
Cyclone Gabrielle
Cyclone Gabrielle was a severe tropical cyclone that struck New Zealand's North Island in February 2023, killing 11 people and becoming the country's costliest non-earthquake disaster.
Cyclone Gafilo
Cyclone Gafilo was an intense tropical cyclone that struck Madagascar twice in March 2004, at the time the most intense cyclone observed in the south-west Indian Ocean.
Cyclone Gezani
Cyclone Gezani was an intense tropical cyclone of the 2025-26 Southwest Indian Ocean season that struck Toamasina, Madagascar, in February 2026, killing 62 people, then re-intensified near Mozambique.
Cyclone Gita
Cyclone Gita was a severe tropical cyclone of the 2017–18 South Pacific season that hit Tonga, Fiji, American Samoa, and New Zealand in February 2018.
Cyclone Gudrun
Cyclone Gudrun, also named Erwin, was an extratropical cyclone that struck Denmark and southern Sweden in January 2005, felling 75 million cubic meters of forest.
Cyclone Heta
Cyclone Heta was a Category 5 severe tropical cyclone of the 2003–04 South Pacific season that struck Samoa, American Samoa, Tonga, and Niue in early January 2004.
Cyclone Hudhud
Cyclone Hudhud was an extremely severe cyclonic storm that formed over the Bay of Bengal in October 2014 and made landfall near Visakhapatnam, Andhra Pradesh, with winds of about 185 km/h.
Cyclone Ianos
Cyclone Ianos (Ιανός) was an intense Mediterranean tropical-like cyclone, or medicane, that struck Greece on 18 September 2020 with hurricane-force winds, record rainfall, and floods that killed four people.
Cyclone Idai
Cyclone Idai, also known as Intense Tropical Cyclone Idai, struck Beira, Mozambique, in March 2019, killing more than 1,300 people across Mozambique, Malawi, and Zimbabwe.
Cyclone Jasper
Severe Tropical Cyclone Jasper was a category 5 cyclone that struck far north Queensland near Wujal Wujal on 13 December 2023, causing record rainfall and flooding.
Cyclone Kenneth
Cyclone Kenneth was an intense tropical cyclone that struck the Comoros and northern Mozambique in April 2019, with 220 km/h winds, the strongest on record to landfall in Mozambique.
Cyclone Maila
Severe Tropical Cyclone Maila was a Category 5 cyclone in the Solomon Sea in April 2026, killing at least 11 people in Papua New Guinea.
Cyclone Montha
Cyclone Montha, or Severe Cyclonic Storm Montha, was a tropical cyclone that crossed the Andhra Pradesh coast of India in October 2025, causing nine deaths.
Cyclone Narelle (2026)
Severe Tropical Cyclone Narelle was a long-lived category 5 tropical cyclone that in March 2026 crossed the Queensland, Northern Territory, and Western Australia coasts at severe intensity.
Cyclone Nargis
Cyclone Nargis, also known as Hurricane Nargis, was a tropical cyclone that struck Myanmar's Irrawaddy delta on 2 May 2008, killing at least 84,537 people.
Cyclone Pam
Cyclone Pam was an extremely destructive Category 5 tropical cyclone that struck Vanuatu on 12–14 March 2015 with sustained winds of 250 km/h, causing the worst natural disaster in the country's recorded history.