Category 1: Continuous rain and flash flood. 25 to 35 mm rain within 6 hours. Valid for: Nordsjælland, Frederikssund, Furesø, Allerød, Hørsholm, Rudersdal and Egedal. Heavy rainfall. Risk of flash flood, flooding of low-lying areas, flooding of basements, water on roads and viaducts (aquaplaning), and reduced visibility.