Other forms: cloudbursts
A cloudburst is a sudden deluge of rain that sends you running for cover. If the sky looks ominous and gray in the morning, you may want to grab an umbrella in case there's a cloudburst later.
A cloudburst is exactly what it sounds like: torrential rain that seems to burst from a saturated cloud. This American English word was coined in the early 19th century, modeled after the German Wolkenbruch, or "cloud break." Whenever the weather abruptly changes from not raining to a downpour of heavy rain, you can call it a cloudburst.