Storm chasers are known for putting themselves in the path of some pretty gnarly storms in the hope of seeing something amazing. Once in a while, however, the best views don’t come from tornadoes or towering clouds. Instead, they appear after the storms have passed.
He had been crisscrossing the southern Plains and Ozarks all day, beginning with an early-morning trip to Joplin, Mo., from his temporary home in Arkansas. He intercepted a morning storm before blasting west and ending up south of Tulsa. From there, he chased storms near the border with Arkansas before returning to Missouri for Sunday night’s lunar eclipse.
“It was over 800 miles,” he said in a phone interview Tuesday morning, laughing at how crazy his day had been. “The kicker was, it was 20 hours of driving. I probably paid about $120 or $130 in gas.”
The photos Forister captured, however, are mesmerizing — including that of a sky that looks as though it’s covered in bubble wrap.
Forister was among many storm chasers who photographed the otherworldly display.
“Mammatus” originates from the Latin word “mamma,” meaning “udder” or “breast.” Each lobe in a mammatus cloud is usually a few hundred yards across. The lobes organize in disjointed fields that can stretch for miles. Although the clouds in and of themselves are harmless, they often portend severe weather nearby.
Atmospheric scientists still don’t fully understand what makes the clouds. Some hypothesize that pockets of dry and saturated air subsiding from beneath a thunderstorm anvil warm at different rates in their descents, causing turbulent overturning that makes for a lumpy cloud base.
The chase today was meant to be all about intercepting some monster hail out there in eastern Oklahoma but will end up being remembered for that epic #mammatus display near sunset. What a fun day 👍— Jason H (AU) 🇦🇺 (@OreboundImages) May 16, 2022
w/@twstdbro & @shannbil #okwx #TeamBlueMoose #usastormseason2022 #StormHour pic.twitter.com/292RvBgLW5
Another possibility is that evaporative cooling occurs as parcels of air containing precipitation sink beneath an anvil cloud. That cooling causes sinking until the air pocket reaches “equilibrium.” A “restoring force” of rising air curls the edges of that air pocket upward, shaping the base of the clouds into lobes.
Whatever the case, mammatus clouds are a staple of storm chases, especially during sunset, when underside lighting can bathe the protuberances in amber and red hues.
More Mammatus from yesterday's storm in Oklahoma! Love phones and the stuff they can do! Technology is AMAZING! ❤️🙌— Shannon Bileski☈ (@shannbil) May 16, 2022
Second image is of a power pole that was taken out in the storm, hearing 70mph winds were in that one! #LivingMyBestLife #chasecation pic.twitter.com/uecF6TLe0l
The storm Forister chased began in eastern Oklahoma and was one of several that formed along an “outflow boundary,” or the leading edge of cool-air exhaust left behind by the previous day’s storms.
“There was a very obvious outflow boundary lined up just north of Interstate 40, and it was intersecting all little outflow boundaries,” he said. “I just sat there and, eventually, storms fired up.”
Since the storms formed in an environment characterized by high cloud bases and northwest flow, the tornado risk was minimal. Instead, large destructive hail proved the primary hazard. Softball-size stones fell in Okemah in eastern Oklahoma, with reports of baseball-size hail in Wetumka.
“Basically, I didn’t want to [core] punch the supercell because I didn’t want to total my car,” Forister said. Instead, he bailed off the storm, encountering a brief burst of 70 mph winds wrapping around the back side of its circulation.
“Then I sat there and enjoyed the view, and the mammatus display started,” he said. “It ended up being the entire sky being filled with them. They were the perfect shape, size, golden-hour lighting ... the contrast, too.”
Mammatus clouds aren’t rare, and even garden-variety thundershowers in the Mid-Atlantic and Northeast frequently have a few bumps in them. But next-level displays like what Forester encountered are special.
“I stopped at a gas station, and we met up with a whole bunch of friends who had been on the storm, as well,” he said. Among them were Virginia Tech colleagues and University of Oklahoma friends like Andrew Shearer and Elizabeth Spicer, who also had been chasing the storm.
Spicer called the display “truly spectacular.”
“They seemed to grow across the sky, leaving us with an almost 360 degree view,” she wrote. “I had seen these clouds before but never like this. I couldn’t decide where the best view was since we were literally surrounded by these beautiful bulbous clouds.”
The mammatus clouds wound up being a blessing and a curse for Forister. While they were an ephemeral treat in the sky, the parent thunderstorm anvil grew so large that it threatened to blot out another celestial spectacle — the anticipated total lunar eclipse.
“I drove back to southern Missouri, since the anvil of the storms went all the way up to the Kansas line,” Forister said of his pursuit of clear skies.
In the end, he spent 20 hours driving and covered a distance equivalent to traveling from New Hampshire to Raleigh, N.C., but he says it was worth it. His photography site is replete with new adventures, but, more important, he has the memories from his experiences.
“My day yesterday. Witnessed some of the most remarkable views nature has to offer,” he tweeted.
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