The Great U.K. October Cyclone 0f 1987 Western Europes Perfect Storm

1
The Great U.K. October Cyclone 0f 1987Western
Europes Perfect Storm!

• Jonathan Ariel Forest Byrne
• AMS/Blue Hill Observatory
• Boston MA

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Storm Highlights

• Lowest Central Pressure 952 mb
• Lowest observed pressure in 150 yrs!
• Peak wind gust 60m/sec ( 134 mph)
• Observed at Point de Roc near Granville, Normandy
• Highest mean wind speed 38m/sec ( 85mph)
• Observed at Shoreham by the Sea for 20 minutes!
• Widespread wind gusts 42m/sec ( 94 mph)
• Observed across the south coast of the U.K. and
  channel islands

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Regional Impact

• Storm return frequency 200 yrs
• 15 million trees lost resulted in
• Hundreds of blocked railways
• Hundreds of blocked roads
• Additional Statistics
• 20 fatalities
• 1.3 million reported damage incidents
• Economic losses 2.3 billion dollars
• Contributed to the October 1987 stock market
  crash

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Synoptic Overview Antecedent Conditions

• Hurrican Floyd recurvature off the SE coast of
  the U.S contributed to
• Cross mid-Atlantic baroclinic zone, characterized
  by
• A series surface Rossby waves ( or serial
  cyclones).
• Lead (or most eastward) cyclone eventually
  developed explosively into the parent cyclone.
  

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Cyclogenetic Forcings

• Baroclinic instability characterized by a
  meridional 850 mb temperature gradient 0c over
  Ireland 20c south coast of England.
• 85m/sec jet streak that propagated across the
  Atlantic at 30m/sec
• Stacking of lower and upper level PV
• Associated tropopause fold

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A Hybrid Superstorm?

• Type 1A TC to ETC transition with minimal change
  in Integrated Kinetic Energy hybridization
  e.g Hurricane Edna, 1954, NE Hurricane 1938.
• Type 1B TC and ETC spatial and temporal
  interaction resulting in rapid/explosive
  intensification of original ETC hybridization
  e.g. No-Name Storm, Oct. 1991 Saxbys Gale Oct.
  1869.
• Type 2 Rapid spin-up of ETC resulting in hybrid
  characteristics e.g. Superstorm of 1993 Great
  Christmas Noreaster of 1994.

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Conclusion

• The dynamic evolution and synoptic features are
  most consistent with a Type 1b hybrid superstorm.