Cirrus clouds often precede severe weather

Today’s Image of the Day from NASA Earth Observatory features cloud temperature data that was collected by the GOES-R satellite about 45 minutes before a destructive tornado touched down in the Chicago suburb of Naperville on June 20, 2021. Warmer air is red and cooler air is blue.

“Notice the plumes of warm air downwind of updrafts – the cold overshooting cloud tops,” said Kristopher Bedka of NASA’s Langley Research Center. “Those are what we call ‘above-anvil cirrus plumes’ (AACPs) – cirrus clouds that were injected into the stratosphere.”

According to NASA, most thunderstorms can grow up to the tropopause, the boundary between the troposphere and the stratosphere. Here, their tops flatten out, giving them an anvil-like appearance. 

When an intense storm draws cirrus cloud tops into the stratosphere, above-anvil cirrus plumes form. These plumes are usually warmer than underlying anvil clouds.

“Detecting an AACP isn’t a guarantee that you’ll get a tornado or other severe weather like we saw with the Naperville event, but our analysis of more than 400 of these events observed by either GOES-14 or GOES-16 showed about three-quarters of the time these cirrus plumes appeared 10 minutes or more before the most severe weather hits,” said Bedka. 

“Cirrus plumes routinely occur atop the world’s most intense storms, and tracking them can provide valuable lead time that saves lives and property.”

Image Credit: NASA Earth Observatory 

–—

By Chrissy Sexton, Earth.com Staff Writer