On Saturday, the pressure difference over Central Europe between a high with its centre over Scotland and a low over the western Miterranean increas. This caus a bise situation on the northern side of the Alps. The bise increas over the course of Saturday evening and reach its peak in western Switzerland on Sunday evening. During the night into Monday, the storm Juliette (which has since been upgrad and given a name) gradually shift its core from the Gulf of Genoa towards the Balearic Islands. This ruc the pressure gradient and the bise gradually subsid over the course of Monday.
New record values
The striking pressure differences of almost 9 hPa between Zurich and Geneva trigger an extraordinarily strong bise storm, especially in the western parts of the country. Record wind spes were measur for bise conditions in several places. MeteoSwiss weather stations record the highest values since measurements began, at 102.6 km/h in Mathod on the southwest shore of Lake Neuchâtel, 100.8 km/h in St.-Prex on Lake Geneva and 98.6 km/h in Geneva-Cointrin. During the night into Monday and in the morning, a strong bise continu to blow, especially in the west, with gusts of 50 to a maximum of 90 km/h, but it weaken further during the day. On Tuesday, the bise flow will then continue to ease and will only blow weakly to moderately.
The graph shows the maximum wind spes in Geneva spain phone number library since 1981 (only from October to March, to exclude thunderstorm gusts from the northeast), including the record value from yesterday Sunday evening. The next highest value is from 2004 at 95 km/h.
The graphic shows the maximum wind spes in Geneva since 1981 (only from October to March, to exclude thunderstorm gusts from the northeast), including the record value from yesterday Sunday evening. The next highest value is from 2004 at 95 km/h. (MeteoSwiss)
Interesting in this context is the graph below, which shows the hours of gusts at the Zurich/Kloten measuring station for the winter half-year since 1981. You can see a trend of increasing the hours of gusts over the past 40 years. However, this cannot be transferr to the entire Central Plateau.
Bisenstunden Zurich Kloten explanations in the text above
Twilight hours Zurich/Kloten, explanations in the text above (MeteoSwiss)
warnings
On Saturday morning, MeteoSwiss issu strong wind warnings for if you are not satisfi with the select image, delete it the event from Sunday to Monday: in the Lake Geneva region, in the western Jura and in the adjacent Mittelland, stormy with gusts between 80 and 100 km/h, over the Jura 120 to 150 km/h (warning level 3). For the other regions, a warning was issu for 70 to 90 km/h in the lowlands and 80 to 100 km/h in the higher elevations (level 2).
The warning was therefore accurate and the warning period was also well defin, alb directory especially since a warning outlook was issu in advance and people were made aware of the impending event in good time.
The forecasts of the various models also point quite reliably to the Bisen storm at an early stage and had captur the event well both in terms of timing and intensity.
