The most potent thunderstorms roil and churn, like a pot of boiling water.
With the National Oceanic and Atmospheric Administration's (NOAA) latest weather-imaging satellites, this aggressive storm behavior is easily visible from space. Such dynamic thunderstorm activity was on full display Monday, when conditions ripe for severe weather and tornadoes swirled over the Southern Plains. NOAA's GOES-16 satellite captured the action from some 22,000 miles above Earth.
"It looks like a big bomb going off," said Jeff Weber, a meteorologist with the University Corporation for Atmospheric Research.
#GOESEast saw this powerful storm over Texas as severe weather was starting to ramp up across the central and southern Plains on Monday afternoon. More than 20 tornadoes were reported across Kansas, Missouri, Oklahoma and Texas. More imagery: https://t.co/JeQmIesXtI pic.twitter.com/kpJvdbyXKD
— NOAA Satellites (@NOAASatellites) May 21, 2019
The roiling storms here are supercells, a type of violent thunderstorm that can spawn tornadoes. And indeed, many of these May 20 supercells did form twisting columns of air that swept the ground in the region, noted Weber.
The key elements of this cloud churning appearance are updrafts — potent winds shooting up through a thunderstorm. "The 'boiling appearance' you are seeing is due to the strength of the updraft of the storm," said Kristin Calhoun, a research scientist at NOAA's National Severe Storms Laboratory.
The very nature of thunderstorms is to rapidly transport heat and moisture up from the ground and into the sky. "It rises six to eight miles in the atmosphere in a pretty short amount of time," noted Brian Tang, an atmospheric scientist at the University at Albany. These rising winds travel at 30 to 50 mph, but have hit speeds of up to 100 mph, Tang said.
Eventually the warm air and water-rich clouds reach the top of the thunderstorm where it "billows out," explained Weber. Gravity then pulls the clouds back down, creating the roiling effect.
"That's indicative of a very powerful storm," said Weber.
Impressive view of severe thunderstorms moving from Texas into Oklahoma from GOES-16 1-min visible imagery over 1.5 hr time period. Rapid initiation to development of OTs and AACPs. #txwx #okwx pic.twitter.com/5xCq9x4s6W
— Bill Line (@bill_line) May 20, 2019
In severe-weather prone places, like the U.S. plains, a calm cloud can rapidly transform into a fuming supercell thunderstorm. That's why, when viewed from space, these storms sometimes appear to burst out of the atmosphere. "On these really violent days we can see a cloud go from a normal cloud to a severe thunderstorm in a matter of 20 minutes," said Stephen Strader, a severe weather expert at Villanova University who chases these storms through the U.S. plains. "Within 30 minutes [the storm] could have a tornado warning."
When we view NOAA's satellite imagery, though, we're seeing a sped up version of what's transpired on Earth. It's a time-lapse of detailed satellite photography. But the boiling motion is the same. "It's moving," said Tang. "Just like a pot of water on a stove."
Today, this boiling atmospheric behavior is now clearly visible because NOAA's newest weather imaging satellites, GOES-16 and GOES-17, can take highly-detailed images every 30 seconds. GOES-16, which captured the roiling storms above the Texas Panhandle, is situated over the equator and can see the entire U.S.
Image: Kristin Calhoun / Noaa
On May 20, a number of powerful supercell thunderstorms formed because the right ingredients were available and then mixed together. There were bounties of moisture, colliding masses of warm and cool air, and amplified atmospheric instability as air within the developing storms twisted and changed direction while rising even higher.
Severe weather pummeled the region, infrastructure was mangled, trailer homes demolished, and people hurt — but there weren't as many supercell storms as forecasters projected, explained Strader. "The models indicated that this would be a historic event," said Strader. "That’s what didn’t unfold. Society got luckier than we thought was possible."
That's because in Oklahoma a cap of warm air suppressed one of the primary storm ingredients, instability, explained Strader. This cap, born in Mexico, sat over the thunderstorms, keeping a lid on some of the storm activity, Strader explained.
But many roiling storms still formed. And some 20 twisters were spotted in the greater region.
"It certainly was not a busted forecast," said Weber