me·​so·​cy·​clone ˌme-zə-ˈsī-ˌklōn How to pronounce mesocyclone (audio)
: a rapidly rotating air mass within a thunderstorm that often gives rise to a tornado

Examples of mesocyclone in a Sentence

Recent Examples on the Web The tornado forms as the mesocyclone accelerates from the bottom up—and the feature intensifies its rotation, in a way similar to an ice skater who pulls her arms into her body to spin faster, says Jana Houser, a supercell thunderstorm and tornado radar analysis expert at Ohio State University. Catherine Duncan, Smithsonian Magazine, 26 Apr. 2024 Other field campaigns followed, but scientists still haven’t definitively answered why some supercell thunderstorms create tornadoes while others don’t progress beyond a mesocyclone. Carolyn Wilke, Smithsonian Magazine, 1 Nov. 2023 Why there weren’t tornadoes What this squall line did not contain was small pockets of rotation called mesocyclones, which breed tornadoes. Dan Stillman, Washington Post, 30 July 2023 Exceptionally strong wind shear — winds that change in direction or speed with altitude — is needed for mesocyclones to develop, but the strongest shear Saturday afternoon remained well north of the region; there were tornadoes reported in New England. Dan Stillman, Washington Post, 30 July 2023 At one point, three distinct mesocyclones, or areas of rotation — each of which could have spawned a tornado — were orbiting one another. Matthew Cappucci, Washington Post, 20 Apr. 2023 Vertical wind shear can enable the midlevels of the storm to rotate, and upward suction from this mesocyclone can intensify the rotation within the storm's outflow into a tornado. CBS News, 3 Apr. 2023 Some research suggests that a wider mesocyclone is more likely to create a stronger, longer-lasting tornado than other storms. CBS News, 3 Apr. 2023 That helped stoke the storm’s updraft, contained within its mesocyclone. Jason Samenow, Washington Post, 5 July 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'mesocyclone.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1963, in the meaning defined above

Time Traveler
The first known use of mesocyclone was in 1963

Dictionary Entries Near mesocyclone

Cite this Entry

“Mesocyclone.” Dictionary, Merriam-Webster, Accessed 19 Jul. 2024.

More from Merriam-Webster on mesocyclone

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!