Shelf Clouds

Just when I thought about putting away my winter coats, the weather turned again. On Tuesday, I was driving home from work when a large mass of storm clouds loomed into view. Within a few minutes, thunder boomed and multiple lightning strikes flashed before me. I was actually enjoying the light show until the heavy downpour of rain came. Even though I had the windshield wipers going full blast, I could barely see the painted lines on the road. I never drove in rain as heavy as this before, and I slowed down along with other drivers on the road in the hope of avoiding an accident. Water swelled and flooded the streets. Suddenly, the storm disappeared as fast as it came, and the sun shone again . . .

Besides giving me a free car wash, Tuesday’s rain inspired me to do a post about storm clouds. This week’s post features storm clouds called shelf clouds. Here is a brief description of them from the Mother Nature Network website:

Shelf clouds are a type of arcus cloud, formed by colliding updrafts and downdrafts. As a storm vacuums up warm air from below, it also pumps out cooler air at the top, which can spill forward, slip below the warm updrafts and condense into a horizontal “shelf” . . . .


Thunderstorm with lightning (panorama photomontage)
Gewitter Thunderstorm.jpg
By sys-one (Franz Mattuschka) (Own work) [CC BY-SA 3.0], via Wikimedia Commons
Thunderstorm with lightning (panorama photomontage)
19 June 2009


This is a shelfcloud in front of a Squall Line (line of severe thunderstorms).
By Jumbo0 (Own work) [GFDL or CC BY-SA 3.0], via Wikimedia Commons
This is a shelfcloud in front of a Squall Line (line of severe thunderstorms). This cloud brought damaging winds and caused a lot of damage.
14 July 2010


Cumulonimbus shelf cloud over Varangerfjord
By Ricksulman (Self-published work by Ricksulman) [GFDL, CC-BY-SA-3.0 or CC BY-SA 2.5-2.0-1.0], via Wikimedia Commons
Cumulonimbus shelf cloud over Varangerfjord
17 July 2006


Some shelf clouds have a blue glow to them. The Mother Nature Network website describes this as a “’glow discharge,’” which “can occur when a thunderstorm is close to the ground, creating a large ‘surface charge density’ for a long, slow-burning lightning strike — similar to how an electrical charge illuminates suspended particles in a fluorescent light bulb.”


Storm, Almaty, Kazakhstan
By Sarik real [Public domain], via Wikimedia Commons
Storm, Almaty, Kazakhstan


Rolling thunderstorm (Cumulonimbus arcus)
By Photo by John Kerstholt.original upload by Solitude (From English Wikipedia) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons
Rolling thunderstorm (Cumulonimbus arcus)
photographed on July 17, 2004 in Enschede, The Netherlands


Furthermore, shelf clouds are not always as menacing as they appear to be. They “mainly serve as harbingers of more severe weather on the way — and even then, they’ve been known to exaggerate the threat. ”


Cumulonimbus cloud at the Baltic Sea near island of Öland, Sweden.
Cloud cumulonimbus at baltic sea(1).jpg
By Arnold Paul (Deutsch: Selbst erstelltes Foto) [CC BY-SA 2.5], via Wikimedia Commons
Cumulonimbus cloud at the Baltic Sea near island of Öland, Sweden.
18 July 2005


Shelf cloud in Warsaw
Chmura szelfowa nadciągająca nad Warszawę.jpg
By Dariusz Wierzbicki (Own work) [CC BY 3.0], via Wikimedia Commons
Shelf cloud in Warsaw
5 July 2009


Source for all quotes in this post: “9 scary images of shelf clouds” (a photo gallery with text by Russell McLendon) – Mother Nature Network


4 thoughts on “Shelf Clouds

    1. Yes, I agree! 🙂 In the second to the last photo called “Cloud cumulonimbus at baltic sea(1).jpg,” there is a couple with their arms around each other on the right side of the picture. I can’t believe they are standing there watching the storm come in! Hopefully they came to their senses and left before any bad weather appeared. Getting soaked with rain and possibly getting swept away by a storm tide does not sound romantic to me! 🙂

      Thanks for the great comment and for liking this post and “Shadow Show.” I hope you enjoy the rest of your weekend! 🙂

      Liked by 1 person

        1. I guess I was thinking about news stories I read about people on the shore being swept into the sea by strong ocean waves that suddenly appear without warning. These waves are called “sneaker waves.” They occur here in California and a few other parts of the world. Thanks again for your comments, and I hope you enjoy Sunday too. 🙂

          Liked by 1 person

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