Thunderstorms, possibly with gusts, hail and abundant rainfall. BE AWARE that thunderstorms may occur. Take extra care in exposed areas, like mountains, forest and open terrain. Disruption to outdoor activities is possible.

KNMI Royal Netherlands Meteorological Institute

Thunderstorms are locally expected with: 10 to 30 l/m² in 1 hour, or 20 to 40 l/m² in 6 hours, or 25 to 50 l/m² in 24 hours, possibly with local strong windgusts or hailstones of 1 to 2 cm. Be careful.

Royal Meteorological Institute of Belgium