A horseshoe cloud is a relatively uncommon meteorological phenomenon^[1] which manifests as a cloud in the shape of a horseshoe or inverted letter "U".^[1][2]

They occur when a horseshoe vortex deforms a cumulus cloud.^[2] The clouds are relatively short-lived^[2] and is the last stage before one dissipates.^[3] Horseshoe vortex clouds are a form of "fair-weather" funnel cloud and are similar to the shear funnel type of funnel cloud.^{[citation needed]}

A March 2018 instance was explained by the United States National Weather Service:^[4][5]

As the updraft pushes flattish cumulus clouds up & a horizontal vortex develops from differential updraft speeds... As the vortex climbs, it's caught in the faster horizontal winds aloft, & the middle part of the vortex catches the faster speeds with the ends being slower.

These clouds do not occur often because all the needed conditions rarely occur together.^[3]

References

Wikimedia Commons has media related to Horseshoe vortices at Cumulus clouds.

This cloud–related article is a stub. You can help Wikipedia by expanding it.

• v
• t
• e