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Brittany wave buoy daily means for Apr 2021

Daily means from the Brittany wave buoy for Apr 2021, 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

717 wave-buoy observations covered all 30 days. Typical wave height was 5.9 ft (10th–90th percentile 3.9–9.5 ft), while mean reported wave period; measurement type unavailable was 5.9 seconds (10th–90th percentile 5–8 seconds). Typical wind was 16.1 mph (10th–90th percentile 6.9–24.2 mph). 7 of 2,868 checked values (0.2%) were excluded by quality control. Across 11 comparable years, mean wave height was below the same-month mean of 8.5 ft and mean wave period was below the same-month mean of 7.1 seconds.

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

Typical Wave Height

5.9ft
Mean: 6.3 ft
P10–P90: 3.9 — 9.5 ft
Recorded extremes

2.6 — 12.8 ft

Mean Wave Period

5.9secs
P10–P90: 5 — 8secs
Recorded extremes

4 — 11secs

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 717 hourly samples

Typical Wind

ENE, 16.1mph
Mean: 15.7 mph
P10–P90: 6.9 — 24.2 mph
Recorded extremes

0 — 28.9 mph

Circular concentration: 71%

Available for 710 of 717 hourly samples

Compared With Previous Aprils

Historical baseline from 7,797 observations across 11 years.

Wave Height
6.3ft
2.2ft below mean
Historical mean 8.5ft
Wave Period
5.9s
1.2s below mean
Historical mean 7.1s
Water Temperature
–
Not enough comparable data
Historical mean 12.2°C

Chart showing grouped wave observations for Brittany. 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 Brittany wave buoy

Brittany buoy (WMO 62163) is maintained jointly by the UK Met Office and Météo-France in the Bay of Biscay. Its exposed position west of Brittany monitors Atlantic conditions approaching western France and the western entrance to the English Channel. The international feed can include wind, pressure, temperature and wave observations when available.

Metrics are rows; days run left to right.
Brittany wave buoy daily means Apr 2021Last observation shown
Metric
Mean wave height (ft)57964766467589854676567910116553
Mean observed period(s)6Reported6Reported6Reported5Reported5Reported6Reported6Reported5Reported5Reported6Reported6Reported5Reported6Reported6Reported6Reported5Reported6Reported9Reported8Reported8Reported7Reported5Reported5Reported7Reported7Reported7Reported5Reported5Reported6Reported5Reported
Mean wave power(kW/m)------------------------------
Mean wind directionEconcentration 94%ENEconcentration 99%ENEconcentration 100%ENEconcentration 94%NNEconcentration 96%NEconcentration 98%Econcentration 97%ESEconcentration 96%ENEconcentration 69%NNEconcentration 95%NNEconcentration 94%Econcentration 93%ESEconcentration 99%Econcentration 98%Econcentration 99%ESEconcentration 97%ESEconcentration 67%SEconcentration 92%SSEconcentration 59%Econcentration 50%ENEconcentration 78%Econcentration 89%Econcentration 68%ENEconcentration 69%ENEconcentration 95%ENEconcentration 94%NNEconcentration 94%Nconcentration 97%NNEconcentration 96%NNEconcentration 72%
Mean wind speed (mph)152124161719181714171712242321139911691916822261714136
Mean water temperature(°C)------------------------------

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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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