Windstorm Kyrill

A relatively recent example of a powerful extratropical cyclone was windstorm Kyrill, which left a large trail of damage in its wake on January 18th 2007. The UK, northern France, the Netherlands, Germany, Austria, Poland and the Czech Republic all reported substantial damage, with 45 deaths resulting from the storm.

Storm formation and track
Associated damage and insured losses

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 Formation and track

The origins of Kyrill crossed the east coast of North America at midday on January 16th, and, propelled by an exceptionally fast jet stream, reached the UK in just two days. As the system moved into the Atlantic it developed rapidly, with subsequent interactions with the jet stream resulting in a second low forming ahead of the initial low pressure system, which would go onto to become windstorm Kyrill.

Coupled with developing high pressure areas over southern Europe (see Figure 1), Kyrill enabled the formation large pressure gradients, which led to the high windspeeds measured across Europe. Unlike most systems, as Kyrill passed over the UK it deepened briefly, sustaining damaging winds as it moved into mainland Europe .

Figure 1: Click on image to open in a new window

Figure 1 shows an analysis chart at 0000GMT on 19th January 2007. Areas of high pressure over southern Europe, coupled with the low pressure system led to damaging winds over much of Northern Europe.

Kyrill was not an unusual windstorm in the sense of high windspeeds; however, it was somewhat unusual in that damaging windspeeds persisted for more than 24 hours. This was partly as a result of the reintensification as Kyrill crossed the UK. Kyrill did not have the intensity of the October 1987 storm, but did have similar footprint to Daria, although slightly lower windspeeds, as shown in Figure 2. The highest gust speed observed was 44m/s at Needles Lighthouse, while speeds exceeding 31m/s were recorded throughout central parts of England and Wales, with gusts in coastal areas exceeding 36m/s (Benfield, 2007).

Figure 2: Click on image to open in a new window

  Damage and Losses

Some of the highest windspeeds in the UK since 1990 were recorded as Kyrill struck on January 18th, with gusts up to 80mph causing structural damage to buildings, downing trees and power lines, and significant disruption to transport systems. Nine people lost their lives, while several hundred thousand homes were left without power, and railway lines were closed and flights from major airports cancelled. A British container ship grounded in the English Channel, with her crew airlifted to safety as she leaked 200,000 tonnes of oil, while containers washed ashore. Estimates for insured loss for the UK are in the region of €600m (ABI, 2007).

Germany saw gust windspeeds of up to 125mph in certain parts (Benfield, 2007), as Kyrill, the strongest extratropical cyclone to hit Germany since Lothar in 1999, passed over the country. Eleven people perished and over a million homes were left without power as winds caused widespread property damage. Storm surge coupled with heavy rain led to some coastal areas being flooded.

Wind damage and lowland flooding were also experienced in parts the Netherlands, France, Austria, Belgium, Denmark, Switzerland, Luxembourg, and the Czech Republic. Swiss Re report European-wide insured losses in the region of €3-3.5bn, with the German insurance association, GDV, stating approximately €1.5bn of insured loss was suffered by Germany alone.

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References

ABI (2007). ABI Statistics. www.abi.org.uk. Last accessed 9/1/2008.

Benfield (2007). European Windstorm Kyrill. London, Benfield Limited: 4.

Zanetti,  A. (2008). Natural Catastrophes and man-made disasters  2007. Sigma. Zurich, Swiss Re: 46.