The storm classification table below has been developed by scientists
at the University of Virginia for assessing the relative power of northeasterly
storms in the west-Atlantic. The severity of such storms depends on wave
height, which not only depends on wind strength but also on its duration
and fetch, all necessary conditions to reach a 'fully
developed' sea state. Note that the wind speed is absent from this
wave height (m)
|Average duration (hr)||8||18||34||63||96|
|49.7% (2yr)||25.2% (4yr)||22.1% (5yr)||2.4% (40 yr)||0.1% (1000yr)|
|Beach erosion||minor||modest||across beach||severe||extreme|
|Dune erosion||none||minor||significant||erosion and
|Overwash||none||none||none||severe on low-
Notes: a relative frequency of 50% means one such storm every two years.
0.1% once every 1000 years.
Adapted from Cornelia Dean 'Against the tide, the battle for America's beaches'. 1999. Columbia University Press