What was done
Noting that "a great amount of evidence for changing storminess over northwestern Europe is based on indirect data and reanalysis data rather than on station wind data," the authors investigated trends in storminess over the Netherlands derived from hourly records of 10-m wind speed observations made at thirteen meteorological stations scattered across the country that have uninterrupted records for the time period 1962-2002.

What was learned
Smits et al. report that "results for moderate wind events (that occur on average 10 times per year) and strong wind events (that occur on average twice a year) indicate a decrease in storminess over the Netherlands [of] between 5 and 10% per decade." This result, in their words, "is inconsistent with National Centers for Environmental Prediction-National Center for Atmospheric Research or European Center for Medium-Range Weather Forecasts reanalysis data [our italics], which suggest increased [our italics] storminess during the same 41-year period." However, they further report that "evaluation of trends in geostrophic wind, both from station data and reanalysis data, and evaluation of trends in vector-averaged (upscaled) 10-m wind over the Netherlands point towards inhomogeneities in the reanalysis data [our italics] as the main cause of the discrepancy." Nevertheless, they add that an overestimation in their results "cannot be excluded," although they argue "it is unlikely that the real trend is positive."

What it means
Perhaps the safest thing to conclude from this study is that its near-surface-wind-derived results are not inconsistent with the conclusions of the Waves and Storms in the North Atlantic or WASA Group (1998), who - after reviewing numerous papers on the subject and conducting their own analyses of pertinent data - concluded, in the words of Smits et al., that "the wind climate along the European coast has not become more severe in the past 100 years or so (1881-1995)," or as the Group itself wrote, "the present intensity of the storm and wave climate seems to be comparable with that at the beginning of this century," when, of course, it was significantly colder than it is now.

Reference
WASA Group. 1998. Changing waves and storms in the northeast Atlantic? Bulletin of the American Meteorological Society 79: 741-760.