Warm UK Seas

[Graham Easterling]

Just how cold the sea can be when the wind's generally offshore is well demonstrated here, where the sea temperature at 10S off S America is around 17C, the same as Cornwall at 50N

What may not be appreciated by many is just how fast the SST falls within a few 100m of the shore when the wind turns offshore. In a northerly I've seen 17C at Perranportth, 13C at the Penzance bouy. Yes, if you want to go swimming in the UK, beware of a strong offshore wind. A gentle sea breeze on a sunny day makes a huge difference, it piles up pools of 'warm'  surface water against the shore, often just 2-3' deep.

For a similar reason, the water on many beaches it Portugal (not the Algarve, bit further north) can be colder than SW England, if there's an Azores ridge across southern UK.

Very autumnal this morning. I'm getting a new underwater camera for my birthday in mid October, I'm beginning to regret promising to use it on the day.

Graham

Penzance

[Len W]

Dept of water of course plays a part in SST.

Particularly chilly off SW peninsula across to Brittany atm.

A strong southerly can blow it across to us.

Nice and toasty around IOW.

I suggest you try your camera out in the Jubilee pool.

:-)

Len

Wembury

[Graham Easterling]

That colder patch off Brittany is often there, probably down to tidal mixing. Individual days can show big variations in where the cooler patches are. Using your chart the SST off Devon & Cornwall (16-17C) is still a good degree above normal.

Temperature anomaly averaged over the week ending 25th. (Base period 1981-2010 - I think). About the biggest positive anomaly over the N Atlantic that I can remember seeing.

Real time data around the English coast https://coastalmonitoring.org/realtimedata/ Quite a lot of detail if you dig down.

Graham

Penzance

[Len W]

Yes, tidal currents and upwelling of deep cold water will play their part. It is 90+ metres deep in places off the Brittany coast.

The weather then might move the cold pool about on a daily basis.

Len