MétéoSwiss deploys AI to improve warnings for severe thunderstorms

Five-minute updates could give people across Switzerland more time to react when thunderstorms form. MétéoSwiss has placed a new artificial intelligence system into operation this summer, targeting three hazards that can change rapidly: hail, lightning and intense rainfall.

The system analyses radar and lightning data covering the entire country, then estimates the probability of each hazard during the coming hour. It sends that information to the MétéoSwiss app and website, where users can consult warnings for their location.

MétéoSwiss announced the deployment on August 27, 2026, after four years of development. The Swiss government says the system should help reduce false alarms while allowing warnings to reach the public more quickly. That matters in a country where weather conditions can shift sharply between the Alpine valleys, the Plateau and the Jura.

A warning that arrives sooner can influence practical decisions: whether to postpone a hike, move outdoor equipment, leave an exposed area or protect vehicles from hail. The tool does not predict every storm with certainty. It provides frequently refreshed probabilities that can support faster decisions as conditions evolve.

The model learns from how Swiss thunderstorms move and develop, rather than relying only on a single forecast snapshot. MétéoSwiss trained a deep learning algorithm on a vast dataset of radar and lightning observations collected across Switzerland.

The training process required substantial computing power and took place on supercomputers in Lugano. By processing past patterns, the system learned to connect observed storm signals with the later appearance of hail, lightning and heavy rain. It now repeats that analysis every five minutes, producing a rolling outlook for the next hour.

This approach suits thunderstorms because their location and intensity can change quickly. Radar shows precipitation structures, while lightning data provides information about electrical activity within storms. Together, those inputs give the algorithm a frequently updated picture of developing hazards.

The output is expressed as a probability, not a guarantee. That distinction is important for anyone reading an app alert. A high probability indicates increased risk in a particular area and period. It does not establish precisely where hail will fall, how much rain will accumulate or when the next lightning strike will occur.

Faster warnings have value only when people can understand and act on them. A five-minute refresh gives the public a more current view of storm risk than a forecast that remains unchanged while a cell moves across the country.

For residents, the practical benefit may be straightforward. A hiker can reconsider an exposed ridge. A sports organiser can pause an event. Farmers can move machinery or livestock when hail and heavy rain become more likely. Transport operators and local authorities can also use updated warnings when managing outdoor activity and vulnerable infrastructure.

The national coverage is especially relevant in Switzerland's varied terrain. Thunderstorms can develop near the Alps and affect valleys, passes or nearby communities at different times. An alert designed for one area does not automatically describe conditions elsewhere, which makes location-specific information important.

MétéoSwiss says the system is intended to reduce false alarms as well as accelerate warnings. Better targeting can help preserve public trust, since repeated alerts for storms that never arrive may cause users to ignore later notifications. The new tool therefore supports both speed and selectivity, while leaving people responsible for how they respond.