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Brittany wave buoy daily means for Sep 2020

Daily means from the Brittany wave buoy for Sep 2020, 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

714 wave-buoy observations covered all 30 days. Typical wave height was 5.9 ft (10th–90th percentile 4.2–10.2 ft), while mean reported wave period; measurement type unavailable was 6.9 seconds (10th–90th percentile 5–8 seconds). Typical wind was 11.4 mph (10th–90th percentile 4.7–23 mph) and mean water temperature was 19.7°C (10th–90th percentile 19–20.2°C). 11 of 3,567 checked values (0.3%) were excluded by quality control. Across 10 comparable years, mean wave height was below the same-month mean of 7.5 ft and mean wave period was above the same-month mean of 6.8 seconds.

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

Typical Wave Height

5.9ft
Mean: 6.9 ft
P10–P90: 4.2 — 10.2 ft
Recorded extremes

0 — 26.6 ft

Available for 709 of 714 hourly samples

Mean Wave Period

6.9secs
P10–P90: 5 — 8secs
Recorded extremes

4 — 10secs

Available for 708 of 714 hourly samples

Mean Water Temperature

19.7°C
P10–P90: 19 — 20.2°C
Recorded extremes

17.9 — 20.8°C

Available for 711 of 714 hourly samples

Typical Wind

Variable, 11.4mph
Mean: 12.9 mph
P10–P90: 4.7 — 23 mph
Recorded extremes

0 — 36.9 mph

Circular concentration: 19%

Compared With Previous Septembers

Historical baseline from 7,039 observations across 10 years.

Wave Height
6.9ft
0.6ft below mean
Historical mean 7.5ft
Wave Period
6.9s
0.1s above mean
Historical mean 6.8s
Water Temperature
19.7°C
2°C above mean
Historical mean 17.7°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 Sep 2020Last observation shown
Metric
Mean wave height (ft)4467765545688655610QC rejected655716QC rejected976610
Mean observed period(s)6Reported5Reported7Reported8Reported7Reported6Reported7Reported7Reported6Reported6Reported8Reported8Reported9Reported7Reported6Reported5Reported5Reported6Reported8Reported7Reported8Reported8Reported6Reported8Reported8Reported7Reported7Reported7Reported7Reported7Reported
Mean wave power(kW/m)------------------------------
Mean wind directionSconcentration 97%SSWconcentration 97%Variableconcentration 24%NNEconcentration 91%Nconcentration 98%NNWconcentration 95%Nconcentration 90%ENEconcentration 59%NNEconcentration 81%NNEconcentration 94%NWconcentration 81%WSWconcentration 69%ESEconcentration 98%SSEconcentration 90%Sconcentration 96%Econcentration 92%ENEconcentration 99%Econcentration 96%NEconcentration 47%Nconcentration 53%Econcentration 88%WSWconcentration 31%WNWconcentration 82%WNWconcentration 96%NWconcentration 97%NNWconcentration 52%NWconcentration 71%Wconcentration 79%NWconcentration 51%Wconcentration 80%
Mean wind speed (mph)713891412758116612111315212198101019312719913822
Mean water temperature(°C)19.319.619.619.619.419.519.920.120.019.919.619.819.819.919.920.220.220.020.220.120.120.220.119.318.418.618.719.319.219.1

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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