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K7 wave buoy daily means for Dec 2011

Daily means from the K7 wave buoy for Dec 2011, 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

732 wave-buoy observations covered all 31 days. Typical wave height was 15.1 ft (10th–90th percentile 10.8–25.9 ft), while mean reported wave period; measurement type unavailable was 8.6 seconds (10th–90th percentile 7–10 seconds). Typical wind was 23 mph (10th–90th percentile 11.5–38 mph) and mean water temperature was 8.5°C (10th–90th percentile 7.7–9.6°C). 7 of 3,660 checked values (0.2%) were excluded by quality control. Across 1 comparable year, mean wave height was above the same-month mean of 10.7 ft and mean wave period was above the same-month mean of 7 seconds.

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

Typical Wave Height

15.1ft
Mean: 17.2 ft
P10–P90: 10.8 — 25.9 ft
Recorded extremes

7.9 — 44 ft

Available for 725 of 732 hourly samples

Mean Wave Period

8.6secs
P10–P90: 7 — 10secs
Recorded extremes

6 — 13secs

Mean Water Temperature

8.5°C
P10–P90: 7.7 — 9.6°C
Recorded extremes

7.4 — 10.1°C

Typical Wind

W, 23mph
Mean: 24.8 mph
P10–P90: 11.5 — 38 mph
Recorded extremes

3.5 — 59.8 mph

Circular concentration: 44%

Compared With Previous Decembers

Historical baseline from 733 observations across 1 year.

Wave Height
17.2ft
6.5ft above mean
Historical mean 10.7ft
Wave Period
8.6s
1.6s above mean
Historical mean 7s
Water Temperature
8.5°C
0.6°C below mean
Historical mean 9.1°C

Chart showing grouped wave observations for K7. 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 K7 wave buoy

K7 (WMO 64046) is a UK Met Office buoy west of Shetland in the North Atlantic. Its position monitors ocean weather and sea conditions approaching the Northern Isles. The international feed can include wind, pressure, air and sea temperature, and wave observations when the relevant sensors are reporting.

Metrics are rows; days run left to right.
K7 wave buoy daily means Dec 2011Last observation shown
Metric
Mean wave height (ft)2213231915191320261615191514131114129131115262235222018161612
Mean observed period(s)9Reported7Reported10Reported9Reported9Reported9Reported8Reported9Reported10Reported8Reported8Reported10Reported9Reported9Reported8Reported8Reported8Reported8Reported7Reported8Reported7Reported8Reported10Reported9Reported12Reported10Reported10Reported9Reported8Reported9Reported7Reported
Mean wave power(kW/m)-------------------------------
Mean wind directionWNWconcentration 71%SWconcentration 86%NWconcentration 90%Nconcentration 88%NWconcentration 73%Nconcentration 51%Variableconcentration 9%NNEconcentration 37%NWconcentration 97%Wconcentration 54%SSWconcentration 87%SWconcentration 70%Sconcentration 55%NNWconcentration 89%NWconcentration 93%NWconcentration 93%NNWconcentration 95%NWconcentration 86%SSEconcentration 53%WNWconcentration 96%SSWconcentration 72%SWconcentration 91%Wconcentration 96%WSWconcentration 90%WSWconcentration 88%WSWconcentration 77%WSWconcentration 55%Variableconcentration 20%NNWconcentration 90%SSEconcentration 40%SWconcentration 84%
Mean wind speed (mph)31263219192421354026231921191721241617232426353338282628171722
Mean water temperature(°C)9.19.19.09.08.99.49.79.59.79.89.69.49.19.08.67.87.87.87.77.97.97.67.87.87.97.98.18.38.07.87.6

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.

Which wave period is shown?

The table shows the best period measurement supplied for each observation. It is not necessarily the energy period used to calculate wave power.

Tp
Peak period: the period at the strongest spectral peak.
Tavg
The provider's average wave period.
Tm02
A mean period calculated from the wave spectrum.
Tz
Mean zero-crossing period.
Reported
A legacy value whose period type was not recorded.
Mixed
A daily or monthly mean containing more than one period type.

Wave power needs a genuine energy period (Te). SurfHog does not substitute Tp, Tavg, Tm02 or Tz when Te is missing.

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 UK Met Office.

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