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Kopperl Heat Burst
08-02-2013, 09:24 AM
Post: #1
Kopperl Heat Burst
The Kopperl Heat Burst
Bill Murray | 9:00 am June 15, 2009 | Comments (12)

Quote:Forty nine years later, the people of Kopperl, Texas still refer to the meteorological phenomenon that struck their town during the early morning hours of Wednesday, June 15, 1960 as Satan’s Storm.

Newspapers that morning talked about Lyndon Johnson’s landslide victory to be Texas’ candidate for the Democratic Presidential nomination. Texas Republicans were backing Richard Nixon. President Eisenhower was traveling to Japan, where intense riots were underway as leftists protested the pro-Western government. But the people in Kopperl were just glad to see the sun rise.

Kopperl as a town on the edge of Lake Whitney in Bosque County, Texas, about fifty miles southwest of Fort Worth. It was founded in 1881 and named for a banker, Moritz Kopperl.
It was a typical June night in Kopperl. Skies were mostly clear. Some heat lightning was visible on the horizon. One clump of clouds rolled toward the town after midnight. The temperature was about 70F. Suddenly, a tremendous wind arose. It gusted to over 75 mph over a wide area. A store was unroofed. Trees were knocked over. The temperature shot up with an incredible momentum. In just a few minutes, it rose to over 100F. There are reports that thermometers designed to register temperatures up to 140F actually broke as the alcohol expanded so rapidly with the dramatic heat.

People awakened when their air conditioners went out as power failed. Suddenly, their houses were sweltering saunas. They rushed outside, thinking their houses must be on fire. They found that the air outside was scorching. It was hard to breathe. Lightning flashed. They thought the world was coming to an end. Parents wrapped their terrified children in wet sheets to keep them cool.

The next morning, farmers found that their corn that had been green the day before was cooked on the stalk. Ranchers found their young cotton fields burned to a crisp. Leaves on trees, shrubs, and plants were burned as if there had been a freeze.

The event was unexplained in 1960. But today, we know that it was a heatburst. It is a phenomenon that causes extreme winds, a dramatic rise in temperature and a rapid drop in humidity. It happens when air transported high in the atmosphere by a thunderstorm comes crashing back to earth in a downdraft. Most downdrafts are cool in nature, cooled by evaporating rain. But in a heatburst, there is no rain, and the air heats rapidly by compression, rises at 5.5 degrees F as it descends. The air can warm by over 100 degrees F. It rushes outward when it strikes the ground, much as any downburst. Most result in a 20 degree F rise in temperature. The Kopperl downburst was an extreme event, one of the worst heatbursts ever recorded.

An excerpt from "Texas Weather" by Harold Taft and Ron Godbey, copyright 1975:

Quote:Shortly after midnight on the morning of June 15, 1960, under clear skies and otherwise normal conditions, a damaging, scorching northwest wind struck terror and near disaster to a 25-mile stretch across the northwest side of Lake Whitney for nearly 3 hours.

It was like any other Texas night in mid-June. The temperature was in the 70's, the stars were out and a light breeze was blowing. There had been some lightning earlier, but no one paid much attention to it. The without struck. A searing blowtorch-like wind hit hit with speeds estimated at 80-100mph, and the temeprature jumped from near 70 to 140 degrees!!!

The Mooney Village Store lost the roof and was badly damaged. The interior was smashed and loaves of bread and canned goods blown from the shelves. The strong winds smashed down a huge tree at the home of Mrs. Vergie Moon, near the damaged store. She said it took three people to keep the wind from blowing down her front door. The D.L. Downeys took refuge in their storm cellar, which was soon filled with neighbors seeking shelter from this quite unusual and frightening storm.

The heat and searing wind were stifling. Mothers wrapped their crying babies in wet sheets and towels to protect them from the intense heat. Fire sprinkler systems were set off, car radiators boiled over and panic-striken women were crying, thinking the end of the world had come.

The cotton field (picture) of rancher Pete Burns was scorched by the hot wind. It was an average stand of cotton which he had plowed on Tuesday. The wind and the heat carbonized it, leaving only a few burnt stalks standing. Corn fields in the area, green when the sun went down Tuesday evening, were scorched and wilted at sunup Wednesday.

No one knows for sure how hot it was, but the thermometer outside the Charley Riddle Bait & tackle Shop in Kopperl, jumped from near 70 degrees at midnight to 100 degrees in just a few minutes and the highest was 140 degrees. There was nothing wrong with the thermometer. It was working all right the next day and if anything was reading a little low.

The event would have gone undocumented except for veteran cameraman Floyd Bright who, hearing the incident the next morning, recorded it all on film.

As to what happened....edited for brevity

Scattered thunderstorms had earlier been detected on radar but they disappeared off the scope shortly before midnight. Weather observations at Waco showed a temperature at midnight of 87F.

It may be that the downward thrust of air (downdraft) continued even after the rain shaft dissipated. in doing so, it would heat at a rate of 5.5F for every 1000 feet.

The downward force of this air from the old dried-up thunderstorm must have been fierce, for heated air tends to rise, not fall. The bases of the thunderstorms that night were 8-10K feet. If the air temperature in the dissipating cloud at a height of 20K feet was 20-25F, then the falling air would be heated by compression another 100F by the time it reached the ground and this added to the initial temperature would be close to the 140F observed.

Except for the film story on file at the television station in Fort Worth, there is no other record of this most unusual Texas storm.

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