Editing Storm (section)

== Classification ==
A strict [[meteorology|meteorological]] definition of a terrestrial storm is a wind measuring 10 or higher on the [[Beaufort scale]], meaning a wind speed of 24.5 [[Metre per second|m/s]] (89&nbsp;km/h, 55&nbsp;mph) or more; however, popular usage is not so restrictive. Storms can last anywhere from 12 to 200 hours, depending on season and geography. In North America, the east and northeast storms are noted for the most frequent repeatability and duration, especially during the cold period. Big terrestrial storms alter the [[oceanographic]] conditions that in turn may affect food abundance and distribution: strong currents, strong tides, increased siltation, change in water temperatures, overturn in the water column, etc.  <!--The storm classification for assessing the relative power of northeasterly storms in the west-Atlantic has been developed by scientists at the [[University of Virginia]]. A relative frequency of 50% means here one such storm every two years and 0.1% once every 1000 years.

{| class="wikitable" style="text-align:center"
|-
! !! Class 1 weak !! Class 2 moderate !! Class 3 significant !! Class 4 severe !! Class 5 extreme
|-
! Average peak wave height (m)
| 2 || 2.5 || 3.2 || 5 || 7
|-
! Average duration (h)
| 8 || 18 || 34 || 63 || 96
|-
! Relative frequency
| 49.7% (2 years) || 25.2% (4 years) || 22.1% (5 years) || 2.4% (40 years) || 0.1% (1000 years)
|-
! Beach erosion
| minor || modest || across beach || severe || extreme
|-
! Dune erosion
| none || minor || significant || erosion and recession || destruction
|-
! Overwash
| none || none || none || severe on low-profile beaches || region-wide
|-
! Property damage
| none || modest || local || community-wide || region-wide
|}
-->
{{clear}}