Swiss better prepared for megastorms, experts say

It's nearly 10 years since Switzerland and other countries in Europe were surprised by a devastating storm called Lothar.

The Swiss were completely unprepared for the extreme weather event on December 26, 1999, which packed winds of almost 250 kilometres an hour, laid waste to buildings and uprooted 10 million trees.

But weather experts say that Switzerland is now better equipped to anticipate storms such as Lothar, which caused 600 million francs worth of damage to buildings and a further 750 million francs of losses in the forestry sector.

“The main progress we have made since Lothar is in numerical forecasting”, Daniel Murer a weather forecaster and warning expert told Swisster.

“Today we have better models and better resolution with grid spacing (identifying specific geographic areas) that can be as low as two kilometres”, he said.

Murer said improved technology means that computers can paint a clearer picture of upcoming weather systems.

There are about 1,000 weather balloons around the world that provide weather data for computers, he said.

These make a series of mathematical calculations to predict the weather, Murer said.

In 1999, a false reading from a weather balloon in Newfoundland, Canada, left Switzerland unprepared for Lothar.

The weather station on the Canadian east coast, where the storm was brewing, was forced to release a second balloon after the first launch failed.

This led to a fateful delay in the transmission of information about the storm.

Lothar subsequently killed 14 people as it swept across Switzerland on Boxing day, with winds reaching record speeds of 249 kilometres per hour on the Jungfraujoch peak and 241 km/hour on the Uetliberg mountain in canton Zurich.

A further 15 workers died during the subsequent clear-up of forest debris.

Initially entering Switzerland via the canton of Jura, Lothar sped to the central part of the country before heading northeast.

“We have moved forward since then,” Adrian Aeschlimann, spokesman for the National Office of the environment (OFEV), told Swisster.

National institutions such as OFEV, MeteoSuisse and the Davos-based institute for snow now work closely together to issue warnings and react appropriately in the case of an oncoming cyclone.

But Switzerland's geography still poses challenges.

“The problem is a hurricane is very difficult to predict, especially with the Alps," Aeschlimann said.

"We can see that it comes from Atlantic, but we don’t know where it will travel.”

As a result, weather forecasters have to respond quickly, he said.

The aftermath of Lothar and major flooding from rainstorms in 2005 has also given rise to a national task force capability and an early warning system.

The task force is activated in the case of a wind storm that is expected to affect several cantons. Its role is to assess damage to forests and buildings and to map out an assitance plan.

Heavy depressions such as Lothar pass through Switzerland every 50 or 100 years in the lowlands and more often in the mountains (every 20 to 50 years).

But global warming and subsequent changing weather patterns could increase the likelihood of extreme storms.

“Due to climate change we must expect further outbreaks of violent storms in the future,” the Swiss environment department said in a statement issued this week.

One way to prepare for such events is to plant a diversity of trees in forests, so they can better withstand heavy winds, the department said.