  The 10-minute average wind speed series recorded at 132 stations distributed
rather homogeneously in the territory of Switzerland are investigated. Wind
extremes are defined on the base of run theory: fixing a percentile-based
threshold of the wind speed distribution, a wind extreme is defined as a
sequence of consecutive wind values (or duration of the extreme) above the
threshold. This definition allows to analyse the sequence of extremes as a
temporal point process marked by the duration of the extremes. The average
probability density function of the duration of the extremes of the wind speed
measured in Switzerland does not depend on the percentile-based threshold and
decrease with the increase of the extreme duration. The time-clustering
behaviour of the sequences of the wind extremes was analysed by using the
global and local coefficient of variation and the Allan Factor. The wind
extremes are globally time-clustered, although they tend to behave as a Poisson
process with the increase of the minimum extreme duration. Locally, the wind
extremes tend to be clustered for any percentile-based threshold for stations
located above about 2,000 m a.s.l. By using the Allan Factor, it was revealed
that wind extremes tend to be clustered even at lower timescales especially for
the higher stations.
