Michigan after a recent storm buried the region in three feet of snow. 

Over a dozen cold Canadian whirlwinds, technically known as mesovortices, twisted their way south, creating a snow band that curled over the body of water.

Radar shows the whirlwinds swirling over Lake Michigan, thrusting an avalanche of  ‘lake-effect snow’ onto parts of the United States’ northern border.

Lake-effect snow occurs when cold air passes over the unfrozen and relatively warm waters, transferring warmth and moisture  into the lowest portion of the atmosphere.

The air rises, clouds form and grow into narrow band that produces two to three  inches of snow per hour or more – and this rare event dumped up 35 inches of snow in some regions.

Radar shows the whirlwinds swirling over Lake Michigan, thrusting an avalanche of ‘lake-effect snow’ onto parts of the United States’ northern border

Snow and ice cover the St. Joseph Lighthouses in Michigan as waves crash along the Lake Michigan ice shelf formed along Tiscornia Beach

‘I have never seen such a great example of mesoscale vortices down Lake Michigan as this one here. ‘WILD!!’,’ one local weatherman gushed on social media.

Only a few square-miles near the Great Lakes were effected by the torrent of snow, but the near whiteout impact of that arctic blast buried roads and paralyzed traffic.

The contrast was stark: Michigan City, Indiana, for example, was subsumed in 35 inches, or nearly three feet, of ‘sea smoke’ snow, while the city of South Bend just a half hour west only got 6 inches.

One crucial factor in the sudden, targeted micro-blizzard last Friday was the lake-effect snow.

‘Lake-effect snow is common across the Great Lakes region during the late fall and winter,’ according to one National Weather Service (NWS) resource on the phenomenon.

Meteorologists captured a ‘wild’ weather phenomenon over Lake Michigan after a recent storm buried the region in three feet of snow

Only a few square-miles near the Great Lakes were effected by the torrent of snow, but the near whiteout impact of that arctic blast buried roads and paralyzed traffic

Frozen lighthouses and ice pancakes create winter scene on Lake Michigan

Lake-effect mesovortices are always fascinating, but I can't remember another sequence of them as amazing as this one…

This radar loop is more than *30 hours* (0539z Fri to 1250z Sat)#weather #meteorology pic.twitter.com/5EfBkmtmwS

— Stu Ostro (@StuOstro) January 21, 2024

Lake-effect mesovortices are always fascinating, but I can’t remember another sequence of them as amazing as this one…

The NNWS reported that this ‘intense lake effect snow band’ hit at a snow rate of two to three inches-per-hour across last Friday, creating a new record snowfall (21.9 inches) for La Porte County, Indiana.

Temperatures are warming up following an Arctic blast that left dozens dead, putting millions under a new threat of heavy rain and flooding.

‘Portions of I-94 near Michigan City,’ NWS observers also reported, ‘had traffic backed up for several hours due to numerous crashes and slide offs.’

But this historic and oddly targeted winter downfall — the largest since weather stations in that region began keeping records in 1948 — was only just one feature of Friday’s weather event that captivated and confused meteorologists.
Researchers were amazed by the storm’s unusual radar images: a continuous, long and braided chain of ‘mesovortices,’ a term for significant, but mid-sized weather events that are smaller than the ‘synoptic scale’ events normally seen on a standard weather map.

‘Incredible stuff to see on radar,’ WISH-TV meteorologist Ryan Morse posted to X.

‘Lake-effect mesovortices are always fascinating,’ Weather Channel meteorologist Stu Ostro added, ‘but I can’t remember another sequence of them as amazing as this one.’

Atmospheric scientist Frank Marsik, who teaches at the University of Michigan’s  department of Climate and Space Sciences and Engineering (CLASP), hoped meteorologists-in-training will study this unusual series of meso-scale storms.

‘I am sensing a good term project in the future for any student interested in exploring this past Friday’s (1/19) mesovortices over Lake Michigan,’ Marsik said.

Purdue University meteorologist Robin Tanamachi told the Washington Post that, in her preliminary assessment, the odd snow squalls were caused by ‘converging winds [that] were also angled, behaving like two hands rubbing a rope of dough’

This #TimelapseTuesday, we're looking back to this past Friday, where @NOAA's #GOESEast 🛰️ captured a very cool phenomenon over Lake Michigan—more than a dozen cloud eddies (AKA: mesovortices) in a serpentine pattern that also dumped a lot of snow due to the #LakeEffect.

Check… pic.twitter.com/aWWYsZeLyU

— NOAA Satellites (@NOAASatellites) January 23, 2024

Aerial view of ‘smoke’ effect on Lake Michigan in Chicago

This #TimelapseTuesday, we’re looking back to this past Friday, where @NOAA’s #GOESEast 🛰️ captured a very cool phenomenon over Lake Michigan—more than a dozen cloud eddies (AKA: mesovortices) in a serpentine pattern that also dumped a lot of snow due to the #LakeEffect.

Check… pic.twitter.com/aWWYsZeLyU
— NOAA Satellites (@NOAASatellites) January 23, 2024
Purdue University meteorologist Robin Tanamachi told the Washington Post that, in her preliminary assessment, the odd snow squalls were caused by ‘converging winds [that] were also angled, behaving like two hands rubbing a rope of dough.’
The odd angles, she said, effectively spun up a series of small whirlwinds.
‘Imagine bringing your hands together around a glob of dough, and then moving them in opposite directions,’ Tanamachi explained.
‘You end up with a vertically oriented dough ‘rope’ rotating between your hands. The converging winds did something very similar all along the length of the snow band, creating the meso-vortices.’

Atmospheric scientist Frank Marsik, who teaches at the University of Michigan’s department of Climate and Space Sciences and Engineering (CLASP), hoped meteorologists-in-training will study this unusual series of meso-scale storms
While this chain of meso-scale squalls was reportedly unusual for Lake Michigan, a few regions closer to the equator experience this weather pattern more regularly.
Guadalupe Island off the Pacific coast of Baja California, the Cape Verde Islands and the Canary Islands off the coast of West Africa all commonly experience what’s known as von Karmen vortex shedding.
Named after a co-founder of NASA’s Jet Propulsion Laboratory, Theodore von Kármán, the chain alternating mesovortices typically form as a prevailing wind is obstructed by an oncoming land mass, like an island, a mountaintop, or a volcano.
Friday’s pattern across Lake Michigan managed to create a nearly identical weather event simply with two opposing forces of wind.