Disrupted week ahead (January 6, 2025)

Foehn storm and cold front

The new week begins under the influence of depression Florianecentered on the North Sea. Over the past few hours, the pressure difference between the north and south of the Alps has gradually increased. This morning the southern overpressure between Lugano and Zurich was around 15 hPa, which resulted in a foehn situation extremely strong, even tempestuousin the northern valleys of the Alps. At 10 a.m., the highest wind speeds were 105 km/h in Altdorf and Glarus, and triple-digit gusts were also measured in Gersau (102 km/h) and Vaduz (101 km/h). In the mountains, gusts sometimes reached hurricane values ​​(Gütsch 145 km/h, Piz Martegnas 144 km/h or Säntis 124 km/h).

The foehn is also reflected very well in the temperature values: last night the temperature did not fall below 12 degrees in the St. Gallen Rhine Valley, especially in Oberriet and Bad Ragaz, and the minimum value has even summer of 13.5 degrees in Altdorf. During the day, this stormy foehn continues, with temperatures reaching 16 to 18 degrees in these regions, which sometimes places them in the top 10 highest values ​​ever recorded in January.

Under the influence of the Foehn, this start of the week is initially pleasant, especially in the east and along the Pre-Alps, while in the rest of the country, clouds largely dominate. Temperatures will reach 7 to 10 degrees in the plains with a southwest wind which will strengthen during the day, and may even be a little milder in the northwest of Switzerland. The depression mentioned at the beginning of this article will lead a cold front above our heads late in the afternoon and during the next night, thus ending the foehn phase. As the cold front passes, it may rain temporarily quite heavily, with the snowfall limit initially being around 1500 meters and dropping to around 900 to 1000 meters on Tuesday morning.

Au south of the Alps, humidity is accumulating today and the weather is often humid, especially in the afternoon, when it is very cloudy. With cool temperatures of 3 to 5 degrees, the snowfall limit increases from 800 to 1300 meters.

Trolling skies Tuesday

The conditions then look variable and windy mardi in a trolling sky. The weather will be characterized by an alternation of periods of fairly generous clearing and cloudier moments which may bring some areas of showers, particularly near the Jura along the Pre-Alps.

The snow limit will fluctuate between 600 and 900 meters above sea level depending on the areas and times of day and maximum temperatures will be between 4 and 7 degrees.

Warm front Wednesday

The next front will not be long in coming. From Wednesday morninga warm front will concern us, linked to a depression over the Atlantic Ocean. The start of the day is expected to be very cloudy with fairly frequent precipitation. The snow limit should rise to 1000 to 2000 or even 2200 meters above sea level but could be lower in Valais.

During the afternoon, the precipitation will stop in French-speaking Switzerland and the sky will tend to open up with beautiful patches of sunshine to be expected at the end of the day. Temperatures will be significantly milder since it should be over 10°C at low altitude.

No warm front without cold front

After the warm front will follow the cold front. We are already expecting precipitation during the night from Wednesday to Thursday, but it is especially Thursday afternoon when the cold front passes that precipitation will be most frequent. This deterioration will again be preceded by a short episode of foehn in the Alps.

The snow limit located initially at 1500 m altitude will quickly drop to 800 m, then we expect a few showers down to the plain during the night from Thursday to Friday. But precipitation will then be rare due to the arrival of drier air of polar origin.

Next warm front Friday?

Very possible! Most weather models predict at least some sort of “tongue of hot air” at altitude for Friday. This degradation should not be very active. There will be snowfall especially in the Jura along the Pre-Alps, but possibly also a few flakes even in the plain regions. Forecast still to be confirmed over the coming days.

The week-end next one is still uncertain. According to current forecasts, the weather will be cold with a moderate kiss and variable cloudiness with sunny periods. If there is precipitation, it will be snow up to low altitudes. The most recent forecasts on this subject are available on our website.