Weather and Waves data

The weather data is provided by UK Met Office.

The Wave / Swell height, direction and period data is provided by Open-Meteo.

Visibility

Visibility measures the distance at which an object can be clearly seen.

 

  • VP (Very Poor)      Less than 1 km
  • P (Poor)                   1.1 km to 4 km
  • M (Moderate)        4.1 km to 10 km
  • G (Good)                10.1 km to 20 km
  • VG (Very Good)   20.1 km to 40 km
  • E (Excellent)           Greater than 40 km

UV

UV exposure index and the protection required to help keep you safe:


0          No risk of UV – It’s safe to stay outside.

1-2       Low – You can safely stay out side. Consider sunscreen in direct sunlight.

3-5       Moderate – Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised.

6-7       High – Seek shade during midday hours, cover up and wear sunscreen.

8-10    Very high – Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential.

11        Extreme – Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Beaufort Wind Scale

Barometric pressure

Force -Wind – Wave – Description

            mph    meters

0           0-1            0     Calm-Sea like a mirror.

1           1-3         <0.3  Light Air-Ripples.

2           4-7         <0.6  Light Breeze-Small wavelets. 

3          8-12        <1.2  Gentle Breeze-Large wavelets.

4         13-18       <2     Moderate Breeze-Small waves.

5         19-24       <3     Fresh Breeze-Moderate waves.

6         25-31       <4     Strong Breeze-Large waves.

7         32-38       <5.5  Near Gale-Large waves.

8         39-46       <7.5  Gale-Moderately High waves. 

9         47-54       <10   Severe Gale-High waves. 

10        55-63      <12.5 Storm-Very high waves.

11        64-72      <16    Violent Storm-Exceptionally high waves.

12        72-83      >14    Hurricane-Extreme waves.

 

The standard barometric pressure at sea level is 1013 millibars and a normal range is between 965 and 1040.

High pressure typically indicates good weather, clear skies with the sun warming us and the earths surface.

Low pressure means colder weather, clouds blocking the sun, rain and wind.  Very low pressure over open water creates heavy winds which can turn into hurricanes or  typhoons.

 

Lower barometer means higher sea levels and higher values lower sea levels, roughly 1 millibar is equivalent to 1cm change in the sea level hieght.

Typically this is + / – 30cm, but with extreme pressure / weather changes this can be 60cm or more.

 

Wave data

Height of waves

Waves vary in height, a measurement referred to as ‘significant wave height’ is used, this is the average of the highest third of the waves.  The average most frequent waves will be about half the height of the significant wave and about 15% of waves will be biggger than the significant wave, with maximum wave occuring 1.5 to 2x the significant wave. 
 
Height range
The approximate range is the low and high end of the expected wave range rounded to a whole number (this is due to space available in the bevel).
 
Period of waves offshore 
The wave period is the number of seconds between one wave and the next, but as waves vary in frequency they are measured as the time between significant waves crest to crest.
 
Direction of waves
The arrow shows the average direction on the waves.
If the arrow points towards the coast the waves forecast should be more accurate, if the arrow is parrellel or away from the coast the waves will be smaller.

For a more information see the following links

Met Office – What does this forecast mean

Met Office – Understanding beach forecasts

How to read a shipping forecast

Thewaveshack –  How to read a surf report