2 lovely days here in Penzance.

Quite a bit of sea-breeze convergence cloud, but prolonged warm sunshine in
most coastal spots. 21.2 yesterday, 22.0 degrees today. With virtually no
wind on either day it has felt very warm. Also very good visibilty.

Went swimming off the Battery Rocks (a popular spot amongst locals) the last
2 days, and it never ceases to amaze may how much the sea temperature varies
from day to day close to the shore, even when weather conditions appear very
similar. Today the water was far warmer than yesterday. I can only assume
this was due to what little breeze there was being off-shore yesterday, and
on-shore today.

Graham

Penzance
Cornwall
Holiday Cottage www.easterling.freeserve.co.uk
Penzance Weather www.easterling.freeserve.co.uk/weather.html

"Graham Easterling" wrote in message
...
2 lovely days here in Penzance.

Quite a bit of sea-breeze convergence cloud, but prolonged warm sunshine
in
most coastal spots. 21.2 yesterday, 22.0 degrees today. With virtually no
wind on either day it has felt very warm. Also very good visibilty.

Went swimming off the Battery Rocks (a popular spot amongst locals) the
last
2 days, and it never ceases to amaze may how much the sea temperature
varies
from day to day close to the shore, even when weather conditions appear
very
similar. Today the water was far warmer than yesterday. I can only assume
this was due to what little breeze there was being off-shore yesterday,
and
on-shore today.

Graham

Are you sure it is the water temperature changing, or is it just how it
feels relative to air temperature?

Regards,

Ian Sutherland


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Ian

In this case it was the water temperature. The air temperature was very
similar both days.

I have measured the temperature a couple of feet below the surface on a few
occasions, and changes in temperature of 2 degrees centigrade (which is very
noticeable) from one day to the next are not uncommon. Close in, upwelling
of cold water with an off-shore wind, and accumulation of surface water with
an on-shore is significant. But even out at Sevenstones in the open Atlantic
(http://www.ndbc.noaa.gov/station_pag...?station=62107) variations over 24
hours are quite significant. Yesterday 63.1 to 60.8 in just 3 hours.

Graham

"Ian Sutherland" wrote in message
...

"Graham Easterling" wrote in message
...
It never ceases to amaze may how much the sea temperature
varies
from day to day close to the shore, even when weather conditions appear
very
similar. Today the water was far warmer than yesterday. I can only
assume
this was due to what little breeze there was being off-shore yesterday,
and
on-shore today.

Graham

Are you sure it is the water temperature changing, or is it just how it
feels relative to air temperature?

Regards,

Ian Sutherland

"Graham Easterling" wrote in message
...
I have measured the temperature a couple of feet below the surface on
a few
occasions, and changes in temperature of 2 degrees centigrade (which
is very
noticeable) from one day to the next are not uncommon. Close in,
upwelling
of cold water with an off-shore wind, and accumulation of surface
water with
an on-shore is significant.

.... can't speak for the southwest coast, but certainly the north coast
of Cornwall (roughly Trevose Head northwards) is notorious for the
changes you describe - both in temperature and strength / character of
the sub-surface currents ('undertow'). Most years find the unwary
visiting the area and venturing a little too far out having problems due
to the variability in currents - driven as you say by local on/offshore
winds and reacting to the broader-scale energy driven by low pressure
well out in the North Atlantic. The gradient in temperature between
water close inshore (fed in some places by river-water which at this
time of year can be significantly warmer than the SST), and the
'open-sea' temperatures is quite marked. As the currents fluctuate, then
the ex-river water can be pushed one way or the other and lead to sharp
temperature changes at places not too far from the shoreline. I
understand the marine biologists get very excited about these sort of
things ;-)

Martin.


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