Winter Storm Xynthia kills 62 in Europe

Devastating Winter Storm Xynthia ripped a swath of destruction through Portugal, Spain, France, Belgium, and Germany over the weekend, killing at least 62 people. It was Europe's 5th deadliest winter storm of the past 60 years. Hardest hit was France, where at least 51 died. The storm also caused six deaths in Germany, including a 2-year-old boy blown into a river and drowned. Three people were dead in Spain, and Belgium, Portugal, and England had one fatality each. At least ten people are still missing. Most of the deaths in France occurred when a powerful storm surge topped by battering waves up to 25 feet high, hitting at high tide, smashed though the sea wall off the coastal town of L'Aiguillon-sur-Mer. A mobile home park built close to the sea wall was particularly hard-hit. The sea wall was several hundred years old, built in the time of Napoleon, and locating a mobile home park so close to it showed poor coastal development practices, critics said. The storm cut power to more than 1 million homes in France, and up to 1 million customers in Portugal also lost power. A few wind peak wind gusts measured during the storm:

Portugal
Pampilhosa da Serra 147 km/h (91 mph)
Penhas Douradas 126.1 km/h (78 mph)
Porto (Airport LPPR) 113km/h (70 mph)

Spain
Lardeira: 196.1 km/h (122 mph)
Serra do Eixe: 157 km/h (98 mph)
Campus de Vigo: 146.9 km/h (92 mph)
Gandara: 145.8 km/h (91 mph)

France
Eiffel Tower, Paris: 175 km/h (106 mph)
Saint-Clement of the Whales: 159km/h (99 mph)
Charente-Maritime: 161km/h (100 mph)

A Personal Weather Station in Les Portes-en-Re recorded sustained winds of 143 km/h (89 mph) gusting to 180 km/h (112 mph) before losing power at the height of the storm. According to Meteo France, the maximum recorded gust from Xynthia for elevations lower than 1200m was 160 km/h along the coast and 120 km/h inland. In 1999, Winter Storm Lothar brought gusts of almost 200 km/h to coastal areas and up to 160 km/h in the interior at these lower elevations.


Figure 1. Six-hour animation of the surface winds as Winter Storm Xynthia crossed the Bay of Biscay and smashed into France.

Destructive European storms of the past 60 years:
2010: Winter Storm Xynthia of February 27, 2010 killed 51 people in France, Spain, and neighboring countries, and did $2 - $4 billion in damage. Lowest pressure: 967 mb.

Winter Storm Klaus hit northern Spain and southwest France January 23 - 25, 2009, and was Earth's most costly natural disaster of 2009, causing $5.1 billion in damage and killing 26. Minimum pressure: 967 mb.

Kyrill (January 18, 2007) killed at least 45, with Germany suffering the most fatalities (13). Minimum pressure: 964 mb.

Back-to-back winter storms Lothar and Martin December 26-28, 1999) killed 140 people, 88 of the victims in France. Minimum pressure: 961 mb (Lothar), 965 mb (Martin).

The Burns' Day Storm of 1990 killed 97, mostly in England. Minimum pressure: 949 mb.

The Great Storm of 1987 was Europe's "storm of the century". It killed 22 people in England and France. Minimum pressure: 953 mb.

The North Sea Flood of 1962 killed 318 people--315 of them in Hamburg, Germany.

The North Sea Flood of 1953 killed 2,000 people in the Netherlands and England.

Xynthia's warm air surge sets records
One reason Xynthia became so powerful is that it formed very far south, where it was able to tap into an airmass that was unusually warm and moist. Satellite measurements (Figure 2) showed a plume of high total precipitable water (the amount of precipitation one can produce by condensing all the water vapor from the surface to the top of the atmosphere), about 300% above average, flowing from southwest to northeast along Xynthia's cold front. Enhancing the amount of moisture was the presence of very warm sea surface temperatures 1°C above average along this plume. As this extra moisture flowed into the storm, the moisture condensed into rain, releasing the "latent heat" stored up in the water vapor (the extra energy that was originally used to evaporate the water into water vapor). This latent heat further intensified Xynthia. The storm's central pressure fell to 966 mb at the storm's peak intensity, reached at 18 GMT Saturday after it passed over Spain's northwest corner.

As warm, tropical air surged northeastwards in advance of Xynthia's cold front, it set several all-time high temperature records for the month of February. Melilla, Spain hit 34°C (93°F) at 3pm local time on the 27th, beating previous highest February temperature of 30.6°C, set in 1979. The temperature surged upwards a remarkable 9.1°C (16°F) in one hour as Xynthia's warm front passed through. Record February warmth was also observed in the Canary Islands as Xynthia's warm front passed though.


Figure 2. Satellite measurements show a region of high total precipitable water (the amount of precipitation one can produce by condensing all the water vapor from the surface to the top of the atmosphere) up to 300% above average, flowing from southwest to northeast along Xynthia's cold front. Enhancing the amount of moisture was the presence of very warm sea surface temperatures along this plume, about 1°C above average. If this pool of very warm water is still around in July, it could lead to an earlier than average start to the Atlantic hurricane season. Image credit: Sheldon Kusselson, NOAA/NESDIS, and National Hurricane Center.

Next storm
For the the U.S., the next winter storm of note is a moderately strong low pressure system currently over Texas that is expected to move quickly eastwards today and Tuesday. The storm should bring an inch or so of snow to Atlanta and northeast Alabama, and 2 - 4" to the nearby mountains of South and North Carolina, including Charlotte. After that, the models show a long break from winter storm activity for the Eastern U.S. Beginning Sunday, it looks like it will be the Midwest's turn, when a powerful winter storm will drop out of the Rockies, then move across the northern tier of Midwestern states early next week.

Next post
I'll have a new post Tuesday or Wednesday.

Jeff Masters