Rain warnings are only issued for the danger levels 2 - 5.

Effects:

Local swelling of streams or local flooding possible in areas where the ground is already saturated

Behaviour:

Keep an eye on local weather developments, and act appropriately, according to the information you  receive on the conditions

Description of measurement and prognostic values:

• Sustained rainfall north of the Alps and in the Alps: 30-50 mm/24 h
• Sustained rainfall south of the Alps and in Simplon: 70-100 mm/24 h
• Sustained rainfall in Verbano, Valle Maggia: 100-150 mm/24

Effects:

• Swelling of streams, waterfalls and normally dry ditches, and flooding of exposed cave systems;
• Disruption to road traffic on exposed stretches

Behaviour:

• Keep an eye on local weather developments
• Stay away from water (as well as dry river or stream beds) and from shores and river banks
• Avoid steeply sloping terrain
• Always follow the official recommendations

Description of measurement and prognostic values:

• Sustained rainfall north of the Alps and in the Alps: 50-80 mm/ 24 h, 80-110 mm/48 h, 100-130 mm/72 h
• Sustained rainfall south of the Alps and in Simplon: 100-130 mm/24 h, 130-160 mm/48 h, 160-200 mm/72 h
• Sustained rainfall in Verbano, Valle Maggia: 150-200 mm/24 h, 200-250 mm/48 h, 250-300 mm/72 h

Effects:

• Potential for rivers to overflow onto floodplains and flood zones as well as around lake shores.
• Heavily swollen streams, waterfalls and normally dry ditches, and flooding of cave systems;
• Potential for localised landslides on steeply sloping terrain;
• Failure of drainage and sewer systems;
• Flooding of underpasses, underground garages and cellars/basements;
• Disruption to road and rail traffic.

Behaviour:

• Keep an eye on local weather developments
• Stay away from water (as well as dry river or stream beds) and from shores and river banks
• Avoid steeply sloping terrain
• Always follow the official recommendations

Description of measurement and prognostic values:

• Sustained rainfall north of the Alps and in the Alps: 80-120 mm/24h, 110-150 mm/48h, 130-170 mm 72h
• Sustained rainfall south of the Alps and in Simplon: 130-160 mm/24 h, 160-200 mm/48 h, 200-240 mm/72 h
• Sustained rainfall in Verbano, Valle Maggia: 200-250 mm/24 h, 250-300 mm/48 h, 300-350 mm/72 h

Effects:

• Flooding, even in areas which are not usually prone to flooding;
• Extreme swelling of streams, waterfalls or normally dry ditches, even in areas which are normally at low risk;
• Failure of drainage and sewer systems and flood protection barriers;
• Flooding of underpasses, underground garages and cellars/basements;
• Massive disruption to road and rail traffic;
• High likelihood of landslides on sloping terrain and mudslides.

Behaviour:

• Keep an eye on local weather developments
• Stay away from water (as well as dry river or stream beds) and from shores and river banks
• Avoid steeply sloping terrain
• Always follow the official recommendations

Description of measurement and prognostic values:

• Sustained rainfall north of the Alps and in the Alps: >120 mm/24 h, > 150 mm/48 h, >170 mm/72 h
• Sustained rainfall south of the Alps and in Simplon: >160 mm/24 h, > 200 mm/48 h, >240 mm/72 h
• Sustained rainfall in Verbano, Valle Maggia: >250 mm/24 h, > 300 mm/48 h, > 350 mm/72 h

No evaluation.