Catastrophe modeling firm AIR Worldwide has issued a report on the aftermath of Extratropical Cyclone Xaver, which affected large parts of northern Europe, particularly the United Kingdom, Northern Ireland, Germany, the Netherlands, Belgium, Denmark, southern Sweden, Poland, and the Czech Republic, last week.
Xaver followed approximately five weeks after Windstorm Christian battered Denmark, Germany, the Netherlands, France, UK, and Sweden in late October. AIR estimated insured losses of between €1.5 billion and €2.3 billion [$2.065 billion to $3.165 billion] from Christian.
“Hurricane-force winds caused widespread power outages and travel disruptions throughout the region, but the greatest threat from Xaver resulted from its massive surge,” said Dr. Nicolai Thum, senior research associate at AIR Worldwide.
“Storm surge in the United Kingdom and the Netherlands was the highest seen since the deadly North Sea floods of 1953. However, flood defenses in both countries have been significantly strengthened since then, which helped to limit damage. Storm surge was also significant near Hamburg, which saw significant flooding in 1962 from a similar storm, but coastal defenses around the German city held and damage was limited.”
Power and/or communications disruptions affected 500,000 households throughout northern Europe. The storm also caused widespread travel disruptions, shutting down ferry and rail service and grounding flights.
The UK’s Environment Agency (EA) reported that 1,400 properties were damaged by flooding in coastal communities in Yorkshire, Lincolnshire, northeastern Wales, and by heavy precipitation that caused rivers to burst their banks. According to the EA, more than 2,800 km of flood defenses successfully protected more than 800,000 properties from some of the highest storm surges since 1953. The Thames Barrier was closed twice during the storm, successfully protecting London from flooding.
Dr. Thum noted: “In Germany, 6-meter [app.18 ½ feet] high waves battered Hamburg, the second highest surge level since 1825, the first year for which recorded measurements are available. Tidal floods that hit Hamburg were similar to those that drenched the city in 1962, causing the worst flooding in living memory. Hamburg’s harbor area and historic ‘Fischmarkt’ were submerged by Xaver’s storm surge. However, improved coastal defenses along the North Sea limited Xaver’s impact.”
AIR also pointed out that in the Netherlands, “the Eastern Scheldt barrier was closed for the first time in six years on December 6, just ahead of the high tide. Water levels reached up to 4 m, again the highest since 1953, but the flood defenses protected low-lying regions in the Netherland’s southwest delta. Flood damage reported from the Netherlands has thus far been limited.
“In Denmark the towns of Frederikssund and Frederiksvaerk, northeast of Copenhagen, were evacuated by police.”
Dr. Thum concluded, “Based on initial assessments, Xaver’s wind impact is expected to be less than that of Christian, as wind speeds were generally lower in regions affected by both storms. Winds toppled trees and caused widespread roof damage throughout the affected region, but significant structural damage is expected to be limited.”
Source: AIR Worldwide