Blocked large-scale weather situation
Surface weather map with fronts from this morning at 6 UTC.
Surface weather map with fronts from this morning at! 6 UTC. (Source: German Weather Service, DWD)!
For days now, the general situation in our weather! report has been talking about an “extensive”, “stationary” or “strong” high with its center! over northwestern Europe. A look at the surface weather map shows us that the high! extends from the North Atlantic south of Greenland to the Black Sea! This corresponds to a distance of around 5,000 kilometers! It is therefore clear that such an extensive high will not disappear from the weather map overnight.
The Bise
Pressure distribution over Europe during a bise situation (left picture)! the bise in the Swiss topography (right picture)!
A bise situation is typically triggered by! a high pressure area north or northwest of Switzerland. In the northern hemisphere! the wind blows clockwise around the high and is therefore noticeable here as a northeast! wind (see picture on the left, from our brochure “Typical weather conditions in the Alpine region”). In addition, the flow between the Jura/Black Forest and the Alpine arc is channeled and accelerated towards the west (picture on the right, source relief: https://maps-for-free.com)
The position of the high means that a bise has been blowing on the northern side of the Alps for days. At the weather station on the
Lägern (845 m)
The Bise has been blowing since May 12, 2023 with only short interruptions:
Course of the wind direction in degrees (hourly average) from May 10 to June 3, 2023 at the Lägern weather station.
Course of the wind direction in degrees (hourly average) spain phone number library from May 10 to June 3, 2023 at the Lägern weather station.
The phenomenon also occurs in the free atmosphere.
Balloon ascent in Payerne/VD
, which takes place twice a day, has been measured at around 1500 meters on 39 of 43 dates since May 12, 2023:
Wind direction at 850 hPa (approx. 1500 m) from 10 May to 3 June 2023, derived from radio soundings in Payerne, at 00 and 12 UTC, respectively.
Wind direction at 850 hPa (approx. 1500 m) from 10 May to 3 June 2023, derived from radio soundings in Payerne, at 00 and 12 UTC, respectively.
During the summer months, the bise typically brings dry air to the northern side of the Alps, whereas during the winter months, high fog often dominates.
You can find out more about Bise in our
brochure “Typical weather conditions in the ultimate guide to japanese management the Alpine region”
as well as in our
weather lexicon
.
For how much longer?
Over the course of the coming week, the center awb directory of the high pressure area will slowly shift over Scotland and the North Sea to Scandinavia. Switzerland will therefore remain on the southern edge of the high and the bise situation will remain with us until further notice.