A sizzling heat bubble, en route to the Netherlands, surprises meteorologists

Around 20 degrees on Thursday and locally maybe 25 degrees on Friday. These are special days that the Netherlands can expect for the weekend. This long-term average at the end of October is 13.3 degrees, and going much beyond that is definitely unusual. If it gets hotter than 25.2 degrees, the record that was measured on October 27, 1937 in Maastricht will be broken.

Unusual, but not unique either, says KNMI climatologist Peter Siegmund. Since the start of measurements at De Bilt in 1901, the mercury had exceeded 20 degrees four times earlier at the end of October. Namely in 1937, in 2006 and twice in 2005. “It is plausible that the risk of these kinds of extremes is increasing. But we shouldn’t be too quick to attribute everything to the climate,” says Siegmund.

Pulleys

At first glance, it is simply the weather that plays a role: an area of ​​high pressure over central Europe, combined with a low pressure area between Iceland and the United Kingdom. Together, they form a kind of pulleys, which hoist the hot air northwards via Spain. “Such a southerly flow is more common these days,” says KNMI meteorologist Jos Diepeveen.

However, the imprint of the climate seems to be present in the background. A deeper cause of this hot weather is a U-shaped loop of the so-called jet stream, which currently boasts of the heat in the south and propel it towards Europe. Such loops seem to be becoming more common now that the Earth is warming. Warming is fastest at the North Pole, which is the coldest corner of the world, reducing the temperature difference between the pole and the equator. This in turn causes the jet stream to be “looser” around the earth and detour more often.

Another thing that is further fueling the situation, says meteorologist Diepeveen, is the drought in the south. In Spain, Portugal, Italy and the south of France in particular, the ground has dried up so much that the warm air hardly loses energy by evaporation. For example, a hot air bubble can penetrate much farther into Europe without losing much heat.

ominous clouds

Hundreds of millions of Europeans will already notice or feel it. South of France next weekend will be over 25 degrees, and from Geneva to Berlin the mercury will pass 20 degrees. Only in Great Britain does the rain throw a spanner in the works: there it rains for days, and one can still wonder whether it will be over 20 degrees in any case.

In the Netherlands there is also a small risk of clouds disrupting things, Diepeveen thinks. ‘Everything should be fine. There is a front to the west of us, and if we also get a small cloud field, that’s easy to see with this high temperature,” he said. After all, the sun only shines for a short time each day at this time of year, so there’s less time for the mercury to rise.

The result is in any case good weather, which has not happened for sixteen years, also next weekend. pass halfway next week The temperature is expected to drop further, although there is even a chance on Wednesday that the national daily record of 19.3 degrees (as of November 2, 2020) will fall. However, from this day the chance of rain also increases significantly.