Much too wet first half of November in the north!

Massively too wet in the north in some places

The first half of November was characterized by lows repeatedly passing to the north of us, whose repeated fronts in the north resulted in a much too wet first half of November (see Fig. 1). Locally, Valais, the region with the largest surpluses, received more than five times the normal long-term average precipitation. In the south, on the other hand, under the protection of the Alps, it has so far been widely too dry, in some cases significantly so.

In absolute figures, Clusanfe in Lower Valais and Saentis have had the most precipitation so far, with just under 400 liters (see Fig. 2).

The first snow has already fallen locally in the Swiss Plateau

Last Sunday, a warm front passed over a cold base layer, which meant that the first snowflakes fell locally in the Swiss Plateau before the wind arrived. Especially in the Bernese Plateau, Solothurn and Aargau as far as the Lucerne region, it turned white in places (see Fig. 3). This is a fairly early date for the first snowfall.

About normal temperature

After a much too warm September and October, there has only been a small surplus of a few tenths of a degree across the whole of Switzerland in November (see Fig. 4). It was too mild in the Swiss Plateau, but too cool in the mountains. The reason for this is, among other things, the virtual absence of fog in the Swis Plateau with often windy conditions and thus good mixing of the air masses.

Still largely frost-free in the Swiss Plateau

While the first snow has already fallen locally in the Swiss Plateau, as mentioned above, the first frost at 2 meters above ground has not yet occurred in many places (see Fig. 5). This means that the date for the first frost is significantly later than the long-term average in most places.

Warmest fall since records began likely

So far, the temperature surplus in the fall (September to November) is around 2.9 degrees (see Fig. 6). The mildest fall so far was 2006 with a deviation of around 2.5 degrees. It is therefore quite likely that this will be the warmest fall since records began.

Hardly any sun in the west

With the exception of individual areas in the far east and south, the duration of sunshine was below average (see Fig. 7). Particularly in the west, in the Jura and along the Alps, the sun has hardly shone at all so far in November.

In absolute figures, Boltigen, La Brévine and Chasseral have had the least sunshine so far, with just 9 hours (see Fig. 8).

Windy first half of November

In the first half of November, repeated disturbances in the north brought some very strong and sometimes gale-force winds, especially on the Jura heights and in the mountains. The strongest gust of 177 km/h was recorded on the Jungfraujoch and 161 km/h on Crap Masegn (see Fig. 9). The gale-force gust of 118 km/h in Rünenberg is also noteworthy. The maximum gusts of the small storm depression Frederico, which will pass just north of us on Friday night, are also likely to be in this category.

The number of days with squalls (gusts > 75 km/h) also shows that it was frequently stormy, especially at high altitudes: This is locally in the double-digit range; on the Chasseral, for example, there have been squalls on 13 out of 15 days so far (see Fig. 10).

Northern lights as far as the Alps on November 5

Although not a weather phenomenon, the red northern lights in the Alps on November 5 are also worth mentioning (see Fig. 11). Northern lights that can be observed this far south are very rare.