Press release archive: 2011

European Atlas on adverse weather for transport

21.12.2011 14:57

The Finnish Meteorological Institute together with other four European research institutes has constructed a European atlas on the probabilities and occurrence of adverse weather events for transport. Conceivable impacts of global climate change on the occurrence of these events were also studied.

Photo: Eevu Heikura

Photo: Eevu Heikura

The EWENT project (Extreme Weather impacts on European Networks of Transport) funded by the European Commission under the 7th Framework Programme (Transport, Horizontal Activities) has the objective of assessing the impact of extreme weather on the European transport system. The work is coordinated by VTT Technical Research Centre of Finland.

The intermediate EWENT study provides the first comprehensive climatology of the adverse and extreme weather events affecting the European transport system by estimating the probability of phenomena for the present climate (1971-2000), and also gives an overview of projected changes in some of these adverse and extreme phenomena in the future climate up to the 2050s. The following phenomena were analysed: strong winds; heavy snowfall; blizzards; heavy precipitation; cold spells; and heat waves. In addition, visibility conditions determined by fog and dust events, small-scale phenomena affecting transport systems such as thunderstorms, lightning, large hail and tornadoes, and events that damage the transport system infrastructure were considered.

Weather and climate need to be considered to ensure the functioning of a safe, reliable and sustainable transport system that meets users’ needs for mobility. The weather and the climate affect all parts of the transport system: physical structures; controlling/communication systems; vehicles; and both traffic and infrastructure operations. Adverse weather has negative impacts on transport through reduced capacity and safety. In the worst cases, adverse weather results in economic losses and injuries or even fatalities.

Both negative and positive impacts on the transport sector

There are large differences in the probabilities and intensity of extremes affecting transport systems across Europe. Northern Europe and the Alpine region are impacted most by winter extremes, such as snowfall, cold spells and winter storms, while the probability of extreme heat waves is highest in Southern Europe. Extreme winds and blizzards are most common over the Atlantic and along its coastline. Heavy rainfalls occasionally impact the whole continent. Visibility conditions indicate a general improvement over the decades studied: severe fog conditions seem to have a strong declining trend at some of the main European airports.

The multi-model approach adopted by the researchers indicates robust changes in temperature extremes. However, the projections are less coherent with regard to extremes in precipitation and wind. Both cold extremes and snow events are likely to become rarer by the 2050s. On the other hand, heavy snowfalls are not expected to decrease all over Europe; instead, the models project a slight increase over Scandinavia. Extreme heat is likely to intensify across the entire continent, being more accentuated in the south.

Climate change is expected to have both negative and positive impacts on the transport sector. A reduction in cold events would have many positive impacts, reducing disturbances caused, e.g. by slipperiness, as well as reducing ice at sea and on rivers. On the other hand, the future increase in the frequency and severity of heat waves indicates the need to consider the heat tolerance of various transport modes. The ongoing work packages of the EWENT project will study the impacts and consequences of the climate changes projected.

The EWENT project is carried out by VTT Technical Research Centre of Finland, the Finnish Meteorological Institute, the German Aerospace Center, via donau (Austria), the Transport Economics Institute (Norway), the European Severe Storms Laboratory (Germany), Cyprus Meteorological Institute, Foreca Consulting Ltd (Finland) and the World Meteorological Organisation. EWENT is funded by the European Commission through its 7th Framework Programme.

Additional information:
Dr Heikki Tuomenvirta, EWENT Work Package 2 leader, Finnish Meteorological Institute, tel. + 358 50 5746824,

Dr Pekka Leviäkangas, EWENT Coordinator, VTT Technical Research Centre of Finland,, tel. +358 20 722 2058

Results of the EWENT Work Package 2: Probabilities of adverse weather affecting transport in Europe: climatology and scenarios up to the 2050s PDF

Website of the EWENT project