Possible consequences

In the event of gusts of wind, the orange warning level violent wind warning is announced if violent winds reach between 90 km/h and 100 km/h.

The possible consequences include:

• broken tree branches;
• some fallen trees;
• damaged roofs and chimneys;
• vehicles swerving off the roads;
• localised disrupted road traffic, in particular in wooded areas.

In the event of snow or freezing precipitation, the orange warning level moderate snow or ice warning is announced when there is

• between 11 and 25 cm of snowfall within 12 hours
• or freezing precipitation across the country.

The possible consequences include:

• large quantities of snow or ice for the region concerned,
• very difficult traffic conditions throughout the network, in particular in wooded areas (trees may fall);
• increased risk of road traffic accidents.

In the event of a storm, the orange warning level (severe storm warning) is announced when

• there are violent winds between 90 and 110 km/h
• there is heavy rain between 25 and 35 l/h or hail between 1 and 3 cm
• and CAPE (Convective Available Potential Energy) 1000-2500 J/kg

The possible consequences include:

• significant localised damage to light housing and temporary structures;
• rapid localised flooding of caves and low-lying ground;
• the possibility of fires starting as a result of lightening not accompanied by rain;
• considerable material damage or risk of accidents following strong gusts of wind or hail.

If it gets especially hot, the orange warning level (great heat warning) is announced when the temperatures rise to between 33°C and 35°C with an average temperature of 23°C.

The possible consequences include:

• a risk of health problems, in particular for
  • older people,
  • children,
  • people with chronic illnesses or mental health issues,
  • people who have to take medication,
  • and people living on their own.
• dehydration or heatstroke with the following symptoms:
  • a temperature over 40°C,
  • hot, red and dry skin,
  • headaches,
  • nausea,
  • drowsiness,
  • intense thirst,
  • confusion,
  • convulsions,
  • loss of consciousness.

If it becomes particularly cold, the orange warning level (great cold warning) is announced when temperatures fall to between -11°C et -15°C.

The possible consequences include:

• a risk of health problems, in particular for
  • older people,
  • babies,
  • people with respiratory or cardiac illnesses,
  • people living on their own;
• a possible risk to people in good health who work outside (traffic officers, builders, farmers, etc.);
• hypothermia;
• frostbite.

In the event of rain, the orange warning level (heavy rain warning) is announced when the quantity of rain falling is

• between 31-45 l/m² within 6 hours
• between 41-60 l/m² within 12 hours
• or between 51-80 l/m² within 24 hours.

The possible consequences include:

• heavy rain likely to affect the economic functioning of several sectors of activity;
• flooding in areas that do not usually flood;
• localised unusual rises in the water level of streams and ditches;
• the risk that sanitation systems may overflow;
• potentially difficult road traffic conditions.

In the event of gusts of wind, the red warning level (very violent gale warning) is announced when very strong winds reach above 110 km/h.

The possible consequences include:

• much significant damage to housing, parks and plantations;
• heavily affected forests (significant damage to trees/uprooted trees);
• very difficult traffic conditions throughout the network, cars forced off the road;
• seriously affected air and rail traffic.

In the event of snow or freezing precipitation, the red warning level (severe snow or ice warning) is announced when there is

• a large amount of snow (over 25 cm within 12 hours)
• or freezing precipitation across the country based on expected damage.

The possible consequences include:

• large snowfall or ice which could seriously affect economic and human activity;
• roads swiftly becoming impassable over the whole network;
• a very great risk of air and rail traffic disruptions.

In the event of freezing precipitation:

• significant risk of damage to the high-voltage electricity distribution networks.

In the event of a storm, the red warning level (violent storm warning) is announced when

• there are gusts of wind exceeding 110 km/h
• or rainfall is greater than 35 l/h
• or there is hail larger than 3 cm
• and CAPE (Convective Available Potential Energy) above 2500 J/kg.

The possible consequences include:

• several very violent storms, with large hailstones and destructive gusts of wind;
• very significant localised damage to homes, parks, crops and plantations;
• very serious localised damage to forests;
• a risk of fire following a large number of lightening strikes;
• danger to light accommodation and temporary structures;
• flooding in caves and low-lying areas;
• very high water levels around streams and small rivers.

If it is especially hot, the red warning level (extreme heat warning) is announced when temperatures rise above 36°C with an average temperature of 23°C.

The possible consequences include:

• a general risk of health problems, even for people in good health;

the people at particular risk include:

• older people,
• people with disabilities,
• people with chronic illnesses,
• people with mental health issues,
• people who take regular medication,
• people living on their own;
• children;

• dehydration or heatstroke with the following symptoms:
  • a temperature over 40°C,
  • hot, red and dry skin,
  • headaches,
  • nausea,
  • drowsiness,
  • intense thirst,
  • confusion,
  • convulsions,
  • loss of consciousness.

In the event that it is especially cold, the red warning level extreme cold warning is announced when temperatures fall below -15°C.

The possible consequences include:

• an increased risk of health problems, in particular for
  • older people,
  • babies,
  • people with respiratory or cardiac illnesses,
  • people living on their own;
• a risk for people in good health but who work outside (traffic officers, builders, farmers, etc.);
• hypothermia;
• frostbite.

In the event of rain, the red warning level (torrential rain warning) is announced when the rain is torrential

• over 45 l/m² within 6 hours
• over 60 l/m² within 12 hours
• or over 80 l/m² within 24 hours.

The possible consequences include:

• very heavy rain which may affect economic and human activity for several days;
• very significant flooding, even in areas that are rarely flooded;
• localised torrential rises in the water level in streams;
• extremely difficult road traffic conditions;
• the risk that sanitation systems may overflow.