Tornadoes not a uniquely American phenomenon; Europe gets its share, too
Stars and Stripes June 8, 2003
The sudden, violent and awe-inspiring nature of tornadoes has made them common fodder for legends.
For example, Pecos Bill is said to have lassoed a tornado, leaped onto its back and rode it across the Texas plain until it had calmed itself.
Here’s another one: Europe has no tornadoes.
That, too, is a tall tale of Bunyanesque proportions.
Europe has plenty of tornadoes, perhaps 300 or more a year, according to a study by Nikolai Dotzek, a scientist with the Institute of Atmospheric Physics — in Wessling, Germany.
That figure includes roughly 170 observed tornadoes in 25 countries and an educated guess that about 130 others were not reported because they dropped from the sky too briefly to be observed or landed unseen in unpopulated areas of the continent.
The United Kingdom has the most tornadoes of any European country, about 33 per year. That number jumps to 50 when unreported tornadoes are added.
This makes the United Kingdom the world’s leader in tornadoes based on number of twisters per area of land.
Tornadoes have been spotted on all of the world’s continents except Antarctica. Even in Japan, the tatsu maki has been reported. Australia also has not escaped the wrath of the “cockeyed bob.”
The United States is the world leader when it comes to tornadoes, roughly 1,400 per year. A flurry of funnels in May set a record, with about 400 recorded in seven days, more than doubling the previous record of 171 from May 12 to 18, 1995.
But while tornadoes in America are often muscular and destructive, tossing cars into the air like they were toys and wreaking havoc on trailer courts and downtowns as they dance across the landscape, Europe’s tornadoes rarely cause loss of life or high-dollar damage.
Don’t be fooled, however, warned Dotzek, who received a doctoral degree in meteorology from Germany’s University of Karlsruhe. Europe’s seemingly low risk can be misleading.
In both Europe and the United States, about 75 percent of the tornadoes are weak, he said, and about 22 percent are strong. The rest are violent.
But with fewer tornadoes in Europe, it takes longer for a violent tornado to appear and cause the type of damage seen so often in Oklahoma, Kansas and Texas.
“If we have 10 times fewer tornadoes, then it takes 10 times longer to get a violent effect,” Dotzek said in a telephone interview.
In Germany, which has about 10 observed tornadoes a year, a category F-5 tornado, with wind speeds of 261 to 308 mph, happens every 150 years, he said. An F-3 tornado, with wind speeds of 158 to 206 mph, happens every 40 to 50 years.
“It would be time now for an F-3 tornado or even a stronger one,” he said.
“If one would happen now, we could not say this was surprising. We would say this was expected.”
Large tornadoes have ravaged Europe in recent years. One smashed its way through Bognor Regis in southern England on Oct. 28, 2000, causing $7 million in damage and injuring four people.
Europe’s most destructive tornado tore through the German town of Pforzheim in July 1968, causing $25 million in damage.
“In Germany, we have been extremely lucky in many cases,” Dotzek said.
The tornado in Pforzheim, for example, struck around 10 p.m. and killed two people. Had it been two hours earlier, when a large crowd was gathered in the city center, the toll could have been 200, he said.
Tony Gilbert said the United Kingdom, too, has dodged plenty of bullets when tornadoes have come to visit. Gilbert is an official with the Tornado and Storm Research Organization, a private organization that is trying to better record the frequency and intensity of tornadoes in the United Kingdom.
He investigated a tornado in January 1999 that roared across ground for three miles before lifting into the sky just on the outskirts of the town of Petersfield. He said that tornado cut a swath across the ground 220 yards wide and might have been an F-3 in wind speed.
“I counted up to 150 trees completely uprooted,” he said. It took the roofs off two farmhouses, but caused no deaths or injuries.
And the same storm system that hit Bognor Regis spawned a tornado that struck another coastal town nearby, overturning cars, knocking down walls and blowing out windows.
“It’s lucky it was 6 o’clock in the morning,” Gilbert said. Streets were largely deserted.
Dotzek pointed out a practical reason that cannot be discounted for the limited damage caused by European twisters. European houses are built of brick and stone.
“They can resist tornadoes in a much better way than in the U.S., where you have these wooden frame houses in the Midwest,” he said.
And, of course, trailer courts, with their lightweight, poorly-secured homes, are considered deathtraps for occupants when tornadoes come calling.
America’s Midwest is also a perfect laboratory for tornadoes. For good reason, an area of the Great Plains is known as Tornado Alley.
“All the ingredients you need to create a tornado, you have to the extreme in the U.S.,” Gilbert said.
How tornadoes form is complex and not completely understood. But to grossly oversimplify, tornadoes can occur when cold dry air, like that which drifts over the Rocky Mountains, meets with warm, moist air, like air from the Gulf of Mexico.
Dotzek said the United States would have far fewer tornadoes if the Rockies suddenly vanished.
There are other reasons for the variation in tornado frequency between the United States and Europe.
“You have to take into account that we are at a higher latitude,” Dotzek said.
Boston is on roughly the same latitude as Madrid, Spain. Oklahoma City is almost directly west of the Strait of Gibraltar. The sharp angle of the sun’s rays striking Europe inhibits their ability to heat air to the degree needed to create prime tornado conditions.
Plus, the landscape of Europe changes quickly from mile to mile — from hills to river valleys and back to hills. This is unlike America’s midsection, where the terrain is flat and featureless for hundreds of miles.
The varied terrain, Dotzek said, modifies the wind scooting along the ground. It is broken and stymied and redirected before it can rise into a vortex. Even when it does, a sudden change in the terrain could alter the wind’s course and speed, shortening a tornado’s duration.
“The conditions are no longer favorable,” Dotzek explained.
For these reasons, Dotzek said, it is not surprising that the Netherlands has twice as many tornadoes as the much larger countries of France and Germany. The level Dutch landscape is more similar to that in America’s breadbasket.
Both Gilbert and Dotzek said Europe’s relative lack of destructive tornadoes has lulled many governments into a false sense of security.
Governments do not issue tornado warnings because they don’t want to spread panic.
Europe doesn’t have the Doppler radar that detects wind direction, providing American forecasters with a heads-up on tornadoes. Therefore, Europe’s governments fear issuing too many false alarms.
But, Gilbert and Dotzek said, a disaster in Europe is inevitable and will probably be what it takes to spur action.
“Unfortunately, something bad must happen before the situation will significantly change,” Dotzek said.
Gilbert said the goal of the Tornado and Storm Research Organization, which has about 300 volunteers around the United Kingdom, is to increase awareness of tornado conditions and their horrific possibilities.
“The government doesn’t seem to want to know this,” he said. “It hasn’t happened yet.”
There is movement on this storm front, however. Scientists around Europe are gathering more frequently to discuss tornadoes and other forms of violent weather. There is cooperation between Europe and the United States on the issue.
Dotzek said Europe was a leader in tornado research before World War II, while America lagged. But that changed after the war.
As proof, Dotzek said his study last year of tornado frequency in Europe was the first done since 1917, when German scientist Alfred Wegener estimated “at least 100 tornadoes per year in Europe.”
That figure had been quoted for eight decades before Dotzek’s work.
Dotzek said things are slowly changing in Europe and the interest in tornado research is reviving. That’s a good thing, he said.
“Even if they are less frequent than in the U.S.,” he said of tornadoes, “they are still a threat.”