A buzzing heat bubble, on its way to the Netherlands, surprises meteorologists

About 20 degrees on Thursday and maybe 25 degrees locally on Friday. These are special days that the Netherlands can expect at the weekend. The long-term average at the end of October is 13.3 degrees, and going that far above that is certainly unusual. If the temperature is more than 25.2 degrees, the record that was measured on October 27, 1937 in Maastricht will be broken.

It’s unusual, but also not unique, says climate scientist Peter Sigmund of KNMI. Since measurements began at De Bilt in 1901, mercury has risen above 20 degrees four times earlier at the end of October. Namely in 1937, 2006 and twice in 2005. “It is plausible that the chance of these kinds of extremism will increase. `But we should not be too quick to attribute everything to the climate,'” says Sigmund.

pulleys

At first glance, it’s simply the weather that plays a role: a high pressure area over central Europe, along with a low pressure area between Iceland and the United Kingdom. Together they form a kind of pulley that lifts warm air north across Spain. “Such a southern flow is becoming more common these days,” says Jose Devin, a meteorologist at KNMI.

However, the climate signature appears to be in the background. The deeper reason for this warm weather is a U-shaped ring of the so-called jet stream, which is currently collecting heat in the south and pushing it into Europe. It seems that such episodes are becoming more common now with global warming. Warming is faster in the Arctic, the coldest corner of the world, reducing the temperature difference between the pole and the equator. This in turn results in the jet stream hanging more “flexibly” around the Earth, and that it takes a turn more often.

Another thing that is fueling the situation is drought in the south, says meteorologist Deppvin. In Spain, Portugal, Italy and southern France in particular, the soil has dried up to such an extent that the warm air hardly loses energy due to evaporation. For example, a warm air bubble can penetrate further into Europe, without losing much heat.

annoying clouds

Hundreds of millions of Europeans will notice – or already feel it. In Italy and southern France the temperature will be more than 25 degrees next weekend, and from Geneva to Berlin the mercury will exceed 20 degrees. Only in Great Britain does rain throw a wrench into the works: It’s been raining for days on end, and it’s still questionable whether it will be warmer than 20 degrees anyway.

Depvin thinks there is also a small risk in the Netherlands that clouds will disrupt things. Everything should work just fine. There is a front to the west of us, and if we also get a small cloud field, it’s easy to see with this high temperature, he says. After all, the sun only shines for a short time each day at this time of year, so it has less time to raise the mercury level.

The result is nice weather anyway, which hasn’t happened in sixteen years, next weekend as well. The temperature is not expected to drop again until the middle of next week, although there is a chance on Wednesday that the national daily record of 19.3 degrees (as of November 2, 2020) will fall. However, from that day onwards, the chance of rain also increases dramatically.