Background
The authors write that "extra-tropical cyclone frequency and intensity are currently under intense scrutiny because of the destruction recent windstorms have brought to Europe," and that "several studies using reanalysis data covering the second half of the 20th century suggest increasing storm intensity in the northeastern Atlantic and European sector," a scenario that is often promoted by climate alarmists.

What was done
Barring and Fortuniak analyzed "inter-decadal variability in cyclone activity over northwestern Europe back to AD 1780 by combining information from eight storminess indices applied in a Eulerian framework," which indices "use the series of thrice-daily sea level pressure observations at Lund and Stockholm."

What was learned
The two Swedish scientists say their results show that former reanalysis studies "cover a time period chiefly coinciding with a marked, but not exceptional in our 225-year perspective, positive variation in the regional cyclone activity that has more recently reversed [our italics]," noting that "because of the inter-decadal variations, a near-centennial time perspective is needed when analyzing variations in extra-tropical cyclone activity and the associated weather conditions over northwestern Europe."

In taking this more proper approach, the two researchers were rewarded by finding that (1) "there is no significant overall long-term trend common to all indices in cyclone activity in the North Atlantic and European region since the Dalton minimum," that (2) "the marked positive trend beginning around 1960 ended in the mid-1990s and has since then reversed," and that (3) "this positive trend was more an effect of a 20th-century minimum in cyclone activity around 1960, rather than extraordinary high values in [the] 1990s."

What it means
There is no basis in real-world data to suggest that the global warming of the late 20th century (now long-gone) produced any increase in storminess over northwest Europe.