What is scarier than a tornado? How about a tornado made of fire and poisonous gas!
Incredible video was captured by an awestruck bystander Saturday showing an enormous cloud of smoke and ash looming ominously close overhead. Before long, a tendril-like funnel whirls out over the lake, probably with winds exceeding hurricane force.
This was the scene south of Blythe, a town of just under 20,000 in Southern California along Interstate 10 near the Arizona border. As the afternoon sun baked the ground with air temperatures to 110 degrees, a brush fire developed on the southern edge of town. Before long, the blaze grew into a monster, spewing smoke a whopping 25,000 feet into the air. The smoke plume grew so high it began to rotate, mimicking a supercell thunderstorm.
Winds at the surface were from the south about 10 to 20 miles per hour, so initially the smoke drifted northward. At the mid-levels, the winds came from the north, and high aloft, from the east. The combined change of wind speed and direction with height allowed the cloud to spin.
The red-against-green contrast is picked up very well on radar, depicting the convergence and some circulation within the cell. The cloud even produced a bit of rain, though most of it was evaporated to steam in the furious inferno.
An “overshooting top” can be seen on satellite imagery as well. That is the overachieving part of the cloud, where the rising motion is so strong it punctures through a level it ordinarily isn’t buoyant enough to reach. That’s the signal of a wicked updraft — one strong enough to even produce a tornado.
While intense heating at the ground can often whip up miniature vortices of fire akin to dust devils on steroids, this particular instance was very different. Instead, the rotation came from above. For the first minute of the video, an obvious rotation is perceptible in the behemoth smoke cloud. And notice that it is counterclockwise. This spin was forced by the surrounding environment in the atmosphere. We call this dangerous part of a storm cloud a mesocyclone.
From this rotating blob descended a fingerlike area of intense wind, touching down on the edge of land just over the water. Loosely based on the video, we estimate winds of 80 to 90 mph. Temperatures inside the toxic carbon-dioxide-filled whirl probably topped 500 degrees.
Does the funnel qualify as a tornado? If we look at the American Meteorological Society’s definition, the answer is yes.
According to the AMS, a tornado is defined as a “rotating column of air, in contact with the surface, pendant from a cumuliform cloud.” What happened in Blythe was obviously spinning and touching down — look at the patterns in the waves. And moreover, the convective bubble-up of the smoke plume — known as “pyrocumulonimbus” — is the fire-induced equivalent of any ordinary thundercloud. It doesn’t matter what produced the rotating storm cloud that dropped the tempest; by all definitions, this was a tornado.
But California is no stranger to fire tornadoes in the “gray area” of what technically is classified as a tornado. On April 7, 1926, a lightning strike ignited an oil fire that grew to 6 million barrels just south of San Luis Obispo. Thousands of firewhirls formed. One whirl was particularly intense, equivalent to a strong tornado. It trekked nearly 1,000 yards, lofting a house into the air for 150 feet and killing two occupants.