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2013а].  In  the  early  hours  of  28 th  October,  the  storm
crossed  the  south  of  the  United  Kingdom  and  moved
across  the  southern  North  Sea  towards  Denmark.
About  noon,  the  first  hurricane  force  gusts  (12  Beaufort
(Bft),  >  32.7  m/s,  >  118  km/h)  were  measured  on  the
German  North  Sea  coast.  The  weather  station  at  Sankt
Peter  Ording  recorded  a  gust  of  47.7  m/s  at  12:30  UTC,
the  maximum  value  in  the  meteorological  network  of
Deutscher  Wetterdienst  (German  National  Meteorological ­
  Service).  At  that  time,  the  centre  of  the  storm
was  located  off  the  northwest  coast  of  Denmark  with
a  core  pressure  of  about  968  hPa.  Remarkable  about
this  storm  event  were  the  high  sustained  winds.  Not
only  the  gusts  but  also  the  10-minute  sustained  wind
speeds  reached  hurricane  force,  especially  in  northern
Schleswig-Holstein.  At  the  station  Strucklahnungshorn,
e.g.,  a  10-minute  sustained  wind  of  38  m/s  was  recorded. ­
  During  the  storm's  further  shift  towards  southern
Scandinavia,  the  Danish  weather  station  of  Kegnaes
Fyr,  a  lighthouse  on  the  Baltic  Sea  coast  near  the  border ­
  of  Schleswig-Holstein/Germany,  recorded  a  gust  of
53.5  m/s  (Fig.  1).
About  one  month  later,  on  4 th  December  2013,  low
Xaver  formed  from  a  warm  front  wave  across  the  North
Atlantic  south  of  Greenland.  It  rapidly  strengthened  to
a  severe  storm  [DWD  2013b].  On  its  way  to  Southern
Sweden,  a  squall  line  in  connection  with  the  cold  front
of  the  storm  reached  northwestern  Germany  in  the  afternoon ­
  of  5 th  December,  along  which  the  first  hurricane
force  gusts  occurred  in  the  German  area.  Storm  Xaver
hit  its  peak  development  on  5 th  December  at  18  UTC
with  a  central  pressure  of  960  hPa  over  southern  Sweden. ­
  At  that  time,  the  cold  front  lay  across  the  Western
Baltic  Sea  and  caused  hurricane  force  gusts  also  in  that
region.  Across  the  North  Sea,  the  wind  turned  to  northwestern ­
  directions  which  led  to  several  severe  storm
surges.  While  on  6 th  December  Xaver  relocated  only
slowly  towards  the  Baltic  states,  the  German  North
Sea  and  the  Baltic  Sea  regions  still  experienced  stormy
weather  with  peak  gusts  of  hurricane  force.  In  the
course  of  the  day,  the  wind  turned  from  west  to  northwest ­
  also  on  the  Baltic  Sea.  The  highest  gusts  on  5 th
and  6 th  December  were  between  40  m/s  and  45  m/s.
Notable  are  the  sustained  high  wind  speeds,  persisting
during  the  6 th  December  and  weakening  only  during
the  course  of  7 th  December  in  the  Baltic  Sea.  The  wind
speed  showed  noticeable  variations  of  intensity  due  to
high  atmospheric  instability.
Overall,  storm  Xaver  caused  mostly  lower  wind  speeds
in  the  German  North  Sea  area  and  in  Schleswig-Holstein
than  storm  Christian,  while  it  was  the  opposite  in  the
German  Baltic  Sea  region.
Results  of  the  Measurements  at  the  FINO  Platforms
FINOl
Storm  Christian  approached  FINOl  from  the  southwest. ­
  Already  during  the  early  morning  of  28 th  October
2013  (4  UTC)  atmospheric  pressure  decreased  below
990  hPa  at  the  height  of  the  platform  deck  (22.5  m,  in
the  following  all  heights  refer  to  marine  chart  zero/

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