Weather Blog Making Sense of Holes in the Clouds Scientists speculated about these holes for decades, but it’s now well understood that cavum clouds are caused by airplanes. Read More… About Author See author's posts Post navigation Previous Flood alerts issued across London as Met Office shares weather warningNext Erupting Volcano causes Yellow Alert… Related Stories Spring Rains Saturate Michigan Weather Blog Spring Rains Saturate Michigan April 17, 2026 Eyeing the Richat Structure Weather Blog Eyeing the Richat Structure April 16, 2026 NASA’s SPHEREx Mission Maps Water Ice Throughout Cygnus X Weather Blog NASA’s SPHEREx Mission Maps Water Ice Throughout Cygnus X April 15, 2026