Why is the risk of thunderstorms often so difficult to assess?
A thunderstorm is by definition a local phenomenon that is difficult to prict in terms of time and space. Even if several thunderstorm cells combine to form a larger, organiz system, there is often still considerable uncertainty about the extent and intensity of the impending event.
When assessing the impending thunderstorm activity, meteorologists rely on the analysis of the requir
Ingrients
over a relatively large area. The ingrients of thunderstorms include moisture, instability, and a lifting mechanism. Often all three ingrients are necessary for significant thunderstorm activity. When we add wind acceleration to height (shear), we increase the likelihood that thunderstorms will become more organiz and more severe.
Local thunderstorms are difficult to prict
Things get complicat when it comes to specifying small-scale thunderstorm cells, both geographically and temporally. The difficulty of pricting thunderstorms increases for several reasons:
The presence or absence of the ingrients requir to trigger thunderstorms is not always easy to anticipate. For example, the risk for the afternoon of the next day may be influenc by the remnants of the previous day’s thunderstorm activity (residual cloud cover), which itself is uncertain.
Humidity, instability and air mass changes are very difficult to capture at a local level with a complex topography such as that in Switzerland.
Numerical forecast models are requir that simulate the switzerland mobile database processes associat with cloud microphysics and atmospheric conditions in the lower layers of the atmosphere as realistically as possible. However, even high-resolution models of the latest generation have difficulty correctly capturing all the ingrients of a thunderstorm. One example is wind convergence in the lower layers of the atmosphere, which often triggers thunderstorms.
The difference between the different thunderstorm warnings
MeteoSwiss issues both a severe weather warning or a so-call thunderstorm outlook and short-term warnings of thunderstorms with so-call “flash orages”.
Mium term : Thunderstorm warning outlooks (with or without advance warning) of possible severe thunderstorms for a relatively large area with a time horizon of about 6 to 36 hours. The thunderstorm warning outlooks are shown in hatch form in the app and on the homepage. If an advance warning for thunderstorms is issu at the same time, the authorities are also actively inform.
These warnings are bas on the analysis of the lws celebrates 40 years of the com domain name with exclusive promotions! thunderstorm ingrients mention above and warn the population and, with advance warning, the authorities that conditions are favorable for severe thunderstorms during the defin period. However, this does not mean that severe thunderstorms will actually occur in the entire warn area.
Wall cloud of a thunderstorm in central Switzerland on April 29, 2023.
Wall cloud of a thunderstorm in central Switzerland on April 29, 2023. (Photo: Meteomeldung/App)
Short term : So-call Flash Orage warnings are issu agent email list when a strong thunderstorm is underway that will affect the warn region within the next 30 minutes to 1 hour. In the app and on the homepage, these warnings are not shad, but fill with the color of the warning level. This means that it is no longer a warning outlook, but an active warning. If you receive a Flash Orage warning via the app, for example, it is advisable to seek shelter immiately.