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K7 wave buoy daily means for Apr 2011

Daily means from the K7 wave buoy for Apr 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

718 wave-buoy observations covered all 30 days. Typical wave height was 11.2 ft (10th–90th percentile 6.9–18 ft), while mean reported wave period; measurement type unavailable was 7.7 seconds (10th–90th percentile 6–9 seconds). Typical wind was 19.7 mph (10th–90th percentile 11.4–27.8 mph) and mean water temperature was 8.8°C (10th–90th percentile 8–9.2°C). 1 of 3,590 checked values (0%) were excluded by quality control.

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

Typical Wave Height

11.2ft
Mean: 11.7 ft
P10–P90: 6.9 — 18 ft
Recorded extremes

4.9 — 23 ft

Available for 717 of 718 hourly samples

Mean Wave Period

7.7secs
P10–P90: 6 — 9secs
Recorded extremes

5 — 11secs

Mean Water Temperature

8.8°C
P10–P90: 8 — 9.2°C
Recorded extremes

8 — 10°C

Typical Wind

SW, 19.7mph
Mean: 19.1 mph
P10–P90: 11.4 — 27.8 mph
Recorded extremes

3.4 — 34.5 mph

Circular concentration: 68%

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 Apr 2011Last observation shown
Metric
Mean wave height (ft)12111214161317181071117141216151298898812QC rejected169866
Mean observed period(s)8Reported8Reported7Reported8Reported8Reported8Reported8Reported9Reported8Reported7Reported7Reported9Reported8Reported8Reported10Reported9Reported8Reported8Reported6Reported7Reported8Reported6Reported6Reported7Reported10Reported10Reported7Reported8Reported6Reported6Reported
Mean wave power(kW/m)------------------------------
Mean wind directionSconcentration 94%SWconcentration 96%SWconcentration 95%SWconcentration 79%SWconcentration 93%WSWconcentration 94%Wconcentration 99%Wconcentration 97%Sconcentration 90%SSWconcentration 97%WSWconcentration 87%Wconcentration 98%SSWconcentration 92%SWconcentration 95%WSWconcentration 93%WSWconcentration 99%SWconcentration 98%Sconcentration 96%WSWconcentration 63%SSWconcentration 97%SSWconcentration 75%ESEconcentration 98%Sconcentration 82%SWconcentration 89%SWconcentration 96%Wconcentration 96%SSEconcentration 96%Variableconcentration 19%SEconcentration 93%Econcentration 98%
Mean wind speed (mph)22192525262229231414192421181723211417171121191922151691315
Mean water temperature(°C)8.68.38.18.69.09.08.58.78.79.09.09.08.48.08.08.39.09.49.89.08.88.78.58.88.88.28.99.19.49.6

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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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