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Sevenstones wave buoy daily means for Nov 2012

Daily means from the Sevenstones wave buoy for Nov 2012, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Monthly means for

Latest

Period Summary

Programmatically generated summary. Hog Says

720 wave-buoy observations covered all 30 days. Typical wave height was 7.5 ft (10th–90th percentile 3.9–12.1 ft), while the reported wave period averaged 8.5 seconds (10th–90th percentile 7–10 seconds). Typical wind was 23 mph (10th–90th percentile 9.5–36.9 mph). 13 of 2,863 checked values (0.5%) were excluded by quality control. Across 2 comparable years, mean wave height was below the same-month mean of 8.1 ft and mean wave period was below the same-month mean of 8.6 seconds.

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

Typical Significant Wave Height

7.5ft
Mean: 7.9 ft
P10–P90: 3.9 — 12.1 ft
Recorded extremes

2.3 — 20.3 ft

Available for 708 of 720 hourly samples

Mean Observed Wave Period

8.5secs
P10–P90: 7 — 10secs
Recorded extremes

6 — 13secs

Available for 716 of 720 hourly samples

Typical Observed Wind

W, 23mph
Mean: 22.7 mph
P10–P90: 9.5 — 36.9 mph
Recorded extremes

2.2 — 50.8 mph

Circular concentration: 38%

Available for 714 of 720 hourly samples

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 720 hourly samples

Compared With Previous Novembers

Historical baseline from 1,423 observations across 2 years.

Wave Height
7.9ft
0.2ft below mean
Historical mean 8.1ft
Wave Period
8.5s
0.1s below mean
Historical mean 8.6s
Water Temperature
–
Not enough comparable data
Historical mean 12.6°C

Chart showing grouped wave observations for Sevenstones. Use the table on this page for a text version of the same measurements. To open hourly observations, use a linked day name in the table.

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; days run left to right.
Sevenstones wave buoy daily means Nov 2012Last observation shown
Metric
Mean significant wave height (ft)8979843561096711845710991411891513645
Mean maximum wave height (ft)------------------------------
Mean maximum crest height (ft)------------------------------
Mean maximum trough height (ft)------------------------------
Mean peak period (s)------------------------------
Mean average period (s)------------------------------
Mean period Tm02 (s)------------------------------
Mean zero-crossing period (s)------------------------------
Mean maximum wave period (s)------------------------------
Mean reported period (s)887876698101078111110910889999898789
Mean peak wave direction------------------------------
Mean wave direction------------------------------
Mean directional spread (°)------------------------------
Mean wind directionWconcentration 96%WSWconcentration 97%WSWconcentration 95%WSWconcentration 91%NNWconcentration 71%NWconcentration 76%Wconcentration 97%Wconcentration 84%SWconcentration 96%Wconcentration 95%WNWconcentration 68%WSWconcentration 98%Sconcentration 96%ESEconcentration 78%Econcentration 92%Econcentration 38%NWconcentration 90%SWconcentration 75%Sconcentration 97%SSWconcentration 86%WSWconcentration 39%SSWconcentration 82%WSWconcentration 81%ENEconcentration 66%WSWconcentration 89%NNWconcentration 88%Nconcentration 98%Nconcentration 97%Nconcentration 69%SSWconcentration 50%
Mean wind speed (mph)32292627312217142323192422161211172030222135142630403725104
Mean water temperature(°C)------------------------------

Swipe sideways to see more days.

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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