Around 20 degrees on Thursday and locally maybe 25 degrees on Friday. These are special days that the Netherlands can expect for the weekend. It long-term average at the end of October is 13.3 degrees, and going that far beyond that is definitely unusual. If it gets warmer than 25.2 degrees, the record that was measured in Maastricht on October 27, 1937, will be broken.
Unusual, but also not unique, says climate scientist Peter Siegmund of the KNMI. Since the measurements in Bilthoven started in 1991, the mercury had risen above 20 degrees four times earlier at the end of October. Namely in 1937, in 2006 and twice in 2005. ‘It is plausible that the chance of these kinds of extremes is increasing. But we shouldn’t be too quick to ascribe everything to the climate,’ says Siegmund.
Pulleys
At first glance, it is simply the weather that plays a role: a high pressure area above Central Europe, combined with a low pressure area between Iceland and the United Kingdom. Together they form a kind of pulleys, which hoist warm air to the north via Spain. ‘Such a southerly flow is more common these days,’ says KNMI meteorologist Jos Diepeveen.
Yet the fingerprint of the climate does seem to be present in the background. A deeper cause of this warm weather is a U-shaped loop of the so-called jet stream, which currently bragging about heat in the south and propelling it to Europe. Such loops do seem to be becoming more common now that the Earth is warming. Because of the warming, the pole, as the coldest corner, warms up the fastest, so that the temperature difference between the pole and equator becomes smaller. This in turn has the consequence that the jet stream hangs ‘looser’ around the earth, and takes a detour more often.
Another thing that further fuels the situation, says meteorologist Diepeveen, is the drought in the south. In Spain, Portugal, Italy and the south of France in particular, the soil has dried out to such an extent that warm air hardly loses energy to evaporation. For example, a warm air bubble can penetrate much further into Europe, without losing much heat.
Disturbing Clouds
Hundreds of millions of Europeans will notice – or feel it already. In Italy and South France the coming weekend will be warmer than 25 degrees, and from Geneva to Berlin the mercury will pass 20 degrees. Only in Great Britain does rain throw a spanner in the works: there it rains for days, and it is still questionable whether it will be warmer than 20 degrees anyway.
In the Netherlands there is also a small risk that clouds will disrupt things, Diepeveen thinks. ‘It should all work out 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 that high temperature’, he says. After all, the sun only shines for a short time every day at this time of year, so it has less time to drive up the mercury.
The outcome is in any case nice weather, which has not happened in sixteen years, also next weekend. pass halfway next week The temperature is expected to drop again, although there is even a chance on Wednesday that the national daily record of 19.3 degrees (from November 2, 2020) will fall. However, from that day on, the chance of rain also increases considerably.