Watch pictures of powerful tornadoes dancing like the utterly devastated “Fingers of God” across the plains of the American Midwest and you’ll quickly conclude that this region must be the world’s champion hurricane. But: that only seems to be the case when you look at the brute force of storms. Just get out the numbers and find out that the Netherlands has more than twice as many tornadoes per square meter than those notorious tornadoes. Hurricane Alley†
At least: when you assemble what in the United States is called “spout” and “hurricane”. Tornadoes form from thunderstorms, while spouts can also form under regular clouds. However, in Holland, all such trunk-shaped storms are always called tornadoes or tornadoes, no matter how they originated.
The most powerful so-called hurricanes in the United States, the trunks of the monsters we know from the screams of TV documentaries and movie movies like Cyclone, fueled by thunderstorms known as “giant cells” in the parlance of meteorological muscles. These are powerful thunderstorms that are already circling inside, so that makes the hurricane even more powerful. Moreover, these giant cells are known for the massive amounts of lightning they emit and centimeter-sized hailstones that spread above the ground.
between the two types
And while we sometimes see giant tornadoes like this in the Netherlands – in 2019 another relatively weak Supercell passed over Amsterdam IJ – most cyclones in our country originate in a different way: air rises through plumes under cumulonimbus clouds. Pops up, in English terms.
The typhoon that crossed Zirkzee on Monday was between the two types in terms of strength. It was a real hurricane, but it didn’t form under the strongest type of thunderstorm, a super torrent. At least that’s the first opinion of Peter Grunmeijer, director of the European Severe Storms Laboratory (ESSL), who has been researching hurricanes in Europe throughout his career.
“This appears to be the type of hurricane that forms in the shadow of a fairly strong storm, but it’s not exceptionally strong,” he says. As the winds over land blew in a southeasterly direction, but blew in a westerly direction over the sea, a shift of the winds could occur over Zierikzee, eventually resulting in a hurricane. “This was not a super sale.”
Exactly how powerful the resulting tornado is is still unknown. Meteorologists use the so-called Fujita scale, named after Japanese physicist and meteorologist Ted Fujita. This scale runs from 0 (for the weakest of tornadoes) to 5, and is determined by the amount of damage a tornado causes.
This may sound a bit arbitrary, but since meteorologists can’t just stick an anemometer into a hurricane’s box, it’s currently the best method available. The cyclone that passed over Amsterdam in 2019 was rated F1 based on damage to roof tiles in a ‘strong building’. How the cyclone scaled down in Zierikzee is likely to become clear later this week.