Hello,
Having recently moved to a new area where swell and waves are often too powerful to be prone surfed (my story here Ressources to learn prone foiling and surviving in heavy conditions?),
I had the idea of crunching some historical data to find when waves might be more friendly.
I am lucky, close to where I live we have an “anchored” meteorological buoys transmitting meteorological data on sea conditions (offshore or coastal) via satellite.
And I have access to historical data.
I focused on 2020-2024.
Source : https://candhis.cerema.fr/index.php
Among the tons of indicators the dataset has, I shortlisted 3:
- HM0 (Significant Wave Height) : is is big ?
- SZ13D (Wave Steepness) : is it curvy ?
- TP (Peak Wave Period): is it clean ?
Average value by month.
Without much surprise, it’s bigger in the winter, and the bigger it is, the longer the period.
Results are very significative with an average wave size going from 1m in the summer to 2.5m in the winter.
Steepness of the wave varies through the year but also peaks with swell size in the winter.
I also analyzed the results by tide.
I labeled tides ad the following:
H is the peak of high tide + 1.5 hours around it (45 minutes before and after).
HL1 are the first 4 hours doing from high to low tide.
HL2 are the other 3 or 4 hours left until we reach low tide.
L is the peak of low tide + 1.5 hours around it.
LH1 are the first 4 hours going from low to high tide
LH2 are the other 3 or 4 hours left until we reach high tide
There is no significant or consistant variation in size of wave.
But here is a significant result in curves and periods.
The ~6 hours after peak high tide, are your friends for clamer, mellower waves.
Last, I did some stats by hour of the day.
With great surprises, something very consistent happens around noon with better conditions (smaller, less curvy, longer period).
Is it linked to the sun’s tides ? Or to the warmth ?
Any comment welcome 