significant wave height

{
  "id": "MLC-T-MET-002490",
  "term": "significant wave height",
  "field": "Meteorology and atmospheric science",
  "definition": "The mean or average height of the highest one third of all waves in a swell train or in a wave generating region. It approximates the value an experienced observer would report if visually estimating sea height. When expressed as a range (e.g. Seas 2-4 ft) , indicates a degree of uncertainty in the forecast and/or expected changing conditions (not that all waves are between 2-4 ft). Generally, it is assumed that individual wave heights can be described using a Rayleigh distribution.\n\nExample: Significant Wave Height = 10 ft\n1 in 10 waves will be larger than 11 ft\n1 in 100 waves will be larger than 16 ft\n1 in 1000 waves will larger than 19 ft\n\nTherefore, assuming a wave period of 8 seconds, for a significant wave height of 10 feet, a wave 19 feet or higher will occur every 8,000 seconds (2.2 hours).",
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/significant-wave-height/"
}