High fog – a phenomenon of late autumn and winter
High fog is very rare in spring, summer and early autumn. The reason! for this is that inversions in the range of 1000 to 2000 meters do not last long, since in high pressure weather with a bise! these inversions are usually only weak during the day. Another important factor is the air humidity! which is usually low in summer in such weather conditions, so that high fog cannot! form at all. This is different in winter. At this time of year the lower layers! of air cool down more and more due to the negative radiation balance! which causes the relative air humidity to rise.! At some point condensation sets in and fog forms. The continued negative radiation balance increases the thickness of this layer of fog! When the bise now arises, this layer of cold air is! pushed against the northern slope of the Alps and lifted! The fog cover then changes into high fog.
Average relative sunshine duration [%] of all anticyclonic
Average relative sunshine duration [%] of all anticyclonic northeast conditions! in spring in the period 1981-2010 (88 cases). In spring, anticyclonic northeast conditions! hardly bring any more high fog, and the relative sunshine duration in the Central Plateau is not significantly lower than in the rest of Switzerland.
>Average relative sunshine duration [%] of all! anticyclonic northeast senegal phone number library conditions in spring in the period 1981-2010 (88 cases). In spring! anticyclonic northeast conditions hardly bring any more high fog, and the relative sunshine duration is not significantly lower in the Central Plateau than in the rest of Switzerland. (MeteoSwiss)
The strength of the bise and, to a lesser extent, the cyclonic nature determine the high fog ceiling
>Depending on the strength of the bise, the upper limit of the high fog occupies a different altitude owever, it is not only the strength of the bise that influences the upper limit of the high fog, but also the cyclonic nature. If the bise is determined by high pressure (anticyclonic curvature), the upper limit of the high fog is relatively low because the subsidence pushes the inversion downwards. If the bise is determined by low pressure – as in the last few days with a Mediterranean low – then the upper limit of the high fog is relatively high because the upward movement that generally prevails in low pressure areas further raises the altitude inversion caused by the bise.
Relative duration of sunshine in Zurich between February
26, 2023 and yesterday, March 2, 2023. On February 26, the strong how to quickly find broken links on a website bise still tore holes in the cloud cover. As a result, the high fog, which had a high upper limit due to the low-pressure bise, caused very little sunshine.
Relative duration of sunshine in Zurich between February 26, 2023 alb directory and yesterday, March 2, 2023. On February 26, the strong bise still tore holes in the cloud cover. As a result, the high fog, which had a high upper limit due to the low-pressure bise, caused very little sunshine. (MeteoSwiss)
Even though the sun was able to shine through at times in the Zurich area today, a cloudy layer of haze remained beneath the inversion.
>Even though the sun was able to shine through in the Zurich area today, a cloudy layer of haze remained under the inversion. (
