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Sevenstones wave buoy observations on Wed, Sep 21, 2016

Hourly readings from the Sevenstones wave buoy for Wed, Sep 21, 2016, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Oldest observation available

Daily means for

Latest

Period Summary

Programmatically generated summary. Hog Says

23 wave-buoy observations were recorded during the day. Typical wave height was 5.9 ft (10th–90th percentile 5–7.1 ft), while the reported wave period averaged 10 seconds (10th–90th percentile 8.2–11 seconds). Typical wind was 16.1 mph (10th–90th percentile 9.4–20.8 mph). All 92 checked values passed quality control.

Generated only from the observations and comparisons shown on this page.

Line chart showing wave height, wave period and sea temperature for Sevenstones. Use the detailed observations table below for the same data in text form.

About Sevenstones wave buoy

Sevenstones Lightship (WMO 62107) is a UK Met Office station west of Land's End, near the Seven Stones reef in the Western Approaches. Its exposed offshore position shows Atlantic systems before they reach Cornwall and the western English Channel and provides context for a notoriously hazardous shipping area.

Its current data source reports wave height, wave period, wave direction, directional spread, wind conditions, sea temperature, separate swell and wind-sea components and wave spectra.

Metrics are rows; hours run left to right. Times use your device time zone.
Sevenstones wave buoy hourly observations Wed, Sep 21, 2016Last observation shown
Metric
Significant wave height (ft)65667876555654-667767786
Maximum wave height (ft)------------------------
Maximum crest height (ft)------------------------
Maximum trough height (ft)------------------------
Peak period (s)------------------------
Average period (s)------------------------
Mean period Tm02 (s)------------------------
Zero-crossing period (s)------------------------
Maximum wave period (s)------------------------
Reported period (s)1111111112111110101011111110-1099988899
Peak wave direction------------------------
Mean wave direction------------------------
Directional spread (°)------------------------
Wind directionEEEESESEWSWWSWWSWWSWSWSWSSWSSWSW-SSSWSSWSSWSSWSSWSSWNWNW
Wind speed (mph)1388101011171715914141516-202122212016162516
Water temperature(°C)------------------------

Swipe sideways to see more hours.

Wave metric colour key

Colours move through the scale as each number increases. They do not by themselves mean that conditions are good, safe or suitable for you.

Wave & swell height0–40+ ft
Wave & swell period0–22+ s
Wind speed0–75 mph

The displayed numbers remain the source of truth; colour is an additional visual cue.

What does buoy wave power mean?

kW/m means kilowatts of wave power per metre of wave crest. It describes the rate at which the observed sea state carries energy past the buoy.

Unlike the shore-directed forecast value, buoy wave power is the total power at the observation point. It is not projected towards a particular beach and does not predict breaking wave height.

In deep water, wave power can be calculated with:

P is approximately 0.49 times significant wave height squared times wave energy period.

P is power in kW/m, Hs is significant wave height in metres, and Te is wave energy period in seconds.

  • Provider-reported power is used when available.
  • Otherwise, a value is calculated only when both significant height and a genuine energy period are available. The ≈ symbol marks calculated values.
  • A dash is shown instead of substituting peak, Tm02, zero-crossing or other period measurements.
  • Daily and monthly figures use the mean of hourly-normalized observation power values; they are not calculated from mean height and period.

Wave direction, spectrum, water depth and local bathymetry still matter. Wave power is best read alongside height, period and direction rather than as a standalone surf-quality score.

The observation data displayed on this page is from the Met Office Marine observations.

Learn how SurfHog combines, checks and summarizes observations in the data and methodology notes.

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