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Brittany wave buoy daily means for Dec 2018

Daily means from the Brittany wave buoy for Dec 2018, 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

705 wave-buoy observations covered all 31 days. Typical wave height was 12.5 ft (10th–90th percentile 4.9–20 ft), while mean reported wave period; measurement type unavailable was 7.8 seconds (10th–90th percentile 6–10 seconds). Typical wind was 21.9 mph (10th–90th percentile 8.1–28.9 mph). 3 of 2,820 checked values (0.1%) were excluded by quality control. Across 8 comparable years, mean wave height was below the same-month mean of 13.8 ft and mean wave period was below the same-month mean of 8.3 seconds.

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

Typical Wave Height

12.5ft
Mean: 12.4 ft
P10–P90: 4.9 — 20 ft
Recorded extremes

3.9 — 29.9 ft

Available for 702 of 705 hourly samples

Mean Wave Period

7.8secs
P10–P90: 6 — 10secs
Recorded extremes

5 — 12secs

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 705 hourly samples

Typical Wind

SW, 21.9mph
Mean: 19.9 mph
P10–P90: 8.1 — 28.9 mph
Recorded extremes

1.1 — 40.3 mph

Circular concentration: 63%

Compared With Previous Decembers

Historical baseline from 5,756 observations across 8 years.

Wave Height
12.4ft
1.4ft below mean
Historical mean 13.8ft
Wave Period
7.8s
0.5s below mean
Historical mean 8.3s
Water Temperature
–
Not enough comparable data
Historical mean 13.4°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 Dec 2018Last observation shown
Metric
Mean wave height (ft)14131391111161824129152018201615QC rejected161514101186655556
Mean observed period(s)8Reported7Reported8Reported8Reported7Reported7Reported8Reported9Reported11Reported9Reported6Reported9Reported10Reported10Reported9Reported8Reported8Reported9Reported9Reported8Reported7Reported7Reported8Reported8Reported6Reported6Reported7Reported8Reported8Reported6Reported6Reported
Mean wave power(kW/m)-------------------------------
Mean wind directionWSWconcentration 99%WSWconcentration 99%WSWconcentration 96%SSWconcentration 86%SWconcentration 87%WSWconcentration 97%Wconcentration 93%Wconcentration 98%WNWconcentration 97%SSWconcentration 73%SSWconcentration 62%SSWconcentration 66%WNWconcentration 83%SWconcentration 74%WSWconcentration 87%WSWconcentration 93%SSWconcentration 92%SWconcentration 87%Wconcentration 99%WSWconcentration 94%WSWconcentration 99%SWconcentration 92%SWconcentration 100%Sconcentration 91%SSEconcentration 99%SEconcentration 97%Econcentration 65%Sconcentration 78%Sconcentration 74%SEconcentration 99%SEconcentration 98%
Mean wind speed (mph)26242316252330292512232221182724272624232617201115125471417
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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