Overview
- The KNMI has issued a code yellow for Zeeland, Zuid-Holland, Noord-Holland, Friesland and Groningen after waterhozen were observed at sea and the alert remains in effect.
- Authorities specifically warn people on the water and operators of small boats to be cautious because waterhozen can generate strong, localized wind that may cause damage or injury.
- Waterhozen are short-lived funnel-shaped vortices that form over large water surfaces, become waterhozen only when they touch the water, and usually lose strength after moving onshore.
- KNMI meteorologist Rob Groenland said the historically warm North Sea acts like a ‘battery’ that feeds convective energy into waterhozen, which could make them more frequent in the near term.
- The KNMI stresses the code yellow is a precautionary safety warning rather than a navigation ban, and it highlights the challenge of forecasting single waterhozen because they are very local and brief.