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National Weather Service Glossary

This glossary contains information on more than 2000 terms, phrases and abbreviations used by the NWS. Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years and before many NWS products were directly available to the public. It is the purpose of this glossary to aid the general public in better understanding NWS products.

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The combination of both wind waves and swell. Used to describe the combination or interaction of wind waves and swell in which the separate components are not distinguished. This includes the case when swell is negligible or is not considered in describing sea state. Specifically, Seas2 = S2+W2 where S is the height of the swell and W is the height of the wind wave. When used, Seas should be considered as being the same as the Significant Wave Height