In the aftermath of Winter Storm Xynthia, which struck Europe last weekend (26–28 February 2010) leaving damages that may range from at $2 - $4 billion, meteorology expert Jeff Masters asks (and answers) whether the frequency of such storms is changing, and whether we can expect the frequency to change in the future. 

Masters, who is the director of meteorology at the Weather Underground, concludes in his Wunder Blog: "The best science we have suggests that there has been an increase in intense wintertime extratropical cyclones in the Northern Hemisphere in recent decades, most notably in the Pacific and Arctic. These intense cyclones are expected to increase in number and shift northwards in a warming climate, with northwest Europe at significantly higher risk of seeing an increase in intense storms."  See The Future of Intense Winter Storms for Masters' full discussion. 

Number of intense winter cyclones with central pressure less than 970 mb in the Northern Hemisphere, North Pacific, and North Atlantic between 1899 - 1991. Image credit: Lambert, S.J., 1996: Intense extratropical Northern Hemisphere winter cyclone events: 1899-1991. J. Geophys. Res., 101D, 2131921325. 

Other Online Resources:

Winter Storm Xynthia Kills 62 in Europe.  By Jeff Masters, Wunder Blog, 1 March 2010. 

Violent Storm Strikes Western Europe, NASA's Earth Observatory, 1 March 2010.

Modeler: Europe’s Storm Xynthia Insured Loss Could Hit $4 Billion.  National Underwriter, 3 March 2010.