The climatological autumn has its days numbered and is going to say goodbye in style. After a little rain and mild temperatures, the cold returns to our latitudes. And he is going to do it with force.
However, that is not the worrying thing. The worrying thing is what comes next: that in the rain department, we are going to lose a good part of December.
“Three days of pure cold.” That’s the summary of the rest of the week. And so says Roberto Granda, one of our greatest temperature experts. As he explains, the cold has already been noticeable in the lows on Tuesday. We have seen “drops of up to 4 and 6 degrees across the board.”
Wednesday will be the coldest day of this episode with widespread frost and much of the interior of the country below 10 degrees. However, the coldest night will be Thursday and the minimum temperatures will be below five degrees in most of the peninsular territory.
And after? Then we will have a reminder that we are still in autumn. One of those seasons in which the atmosphere casts lots for what is going to happen just before it happens.
In this case, despite there being many scenarios on the table, the most likely is that at the end of the week a ridge will settle over Spain to collapse almost immediately, allowing a trough from the north to approach our positions. That would mean more rain: not a lot, but it’s something.
Above all, because they may be the last for a long time. The European model has changed its forecast and everything seems to indicate that a NAO+ will be imposed during the first week of December.
NOT positive? In general terms, the North Atlantic Oscillation is the ‘dance’ between the Azores anticyclone and the Icelandic low, the two major atmospheric phenomena that govern the meteorology of the North Atlantic.
When the index we use to “measure who is winning” is negative, the Azores anticyclone is weaker than normal and, for this reason, it cannot block deep Atlantic storms. The direct consequence is that they circulate further south than usual: right at our latitude.
If, as everything seems to indicate, the NAO becomes positive, not a drop of moisture will enter from the west. The storms will move towards high latitudes (near Iceland and the Nordic countries) and, although stability will not be absolute, the situation will be very dry.
Good news for tourism, I guess. Because as Samuel Biener explains, “a predominant flow from the west or southwest, the temperatures could be between 1 and 3 ºC above the average in the center, northern third and on the shores of the Mediterranean” during the December long weekend. We do not have any quantification of what will happen in the south and in the Canary Islands, but we can get an idea.
Imagen | TropicalTridBits
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