Hi Just a quick question regarding wind conditions inland, I have been sailing at Grafham Water for the past few weeks, the last weekend both days had very little wind but plenty of sunshine! It was quite difficult to sail in.

I noticed in the afternoons a few more boats were on the water than in the mornings where there was only myself and perhaps one or two others. I didn't sail in the afternoons, but my question is; are the wind conditions better in the afternoon? Is the wind generally stronger inland after lunch? Could it have something to do with the land cooling?

I've sailed at Grafham for 30 years! 

During the summer, we SOMETIMES get a wind increase at around 5-7PM on summer days.  It has happened every summer I can remmeber, but it NOT predictable, but local weather did not predict it.  Maybe something to do with wind circulations as a result of sea winds.  I read something a while back that suggested you can get these kind of effects a fair way inland in certain conditions.....

Grafham is however a LONG way from the sea!!!

I plan to be at the club on Sunday and hopefully Wednesday next week,

On fine settled days, especially in summer, it is common for mornings to be still and a light breeze to fill in something around 10:30 or 11:00. This is because radiative cooling of the ground overnight causes a temperature inversion that prevents mixing of the air at ground level and a few 10s of metres up where the gradient breeze is stronger. As the sun heats the ground, the inversion breaks down, mixing begins and the breeze fills in. This is exactly the same reason why in the same conditions, you get a clear sky first thing in the morning but fluffy cumulus clouds start appearing from mid-morning onwards.

In terms of sea-breeze moving inland, I live around 30 miles from the south coast and a few times a year, an obvious sea breeze arrives around 18:00 in the evening. The fluffy cumulus clouds disappear and a noticeably cool breeze suddenly fills in from the south-west. I used to fly gliders from a nearby airfield and once enjoyed a late afternoon soaring in the rising curtain of air as the sea breeze arrived - a very noticeable and obvious effect. But conditions have to be perfect for the sea-breeze to get this far inland. 

It`s about 85 miles to grafham from felixstowe so it`s unlikey to be sea breezes,it`s much more likey that people have a lay in !!

Hmm - wind data given by a turbine sales company.

I'd take that with a very large pinch of salt! 

At Hunts if the conditions are right we do get a sea breeze in the height of summer. it normally appears between 1 and 2pm. I remember several oocasions over the last couple of years when the wind suddenly filled in from nothing to a steady F3-4 in a matter of minutes.

Remember Felixstowe is not the closest point on the coast from Grafham, I would suggest that the Wash/Norfolk coast is closer (not by much, but Grafham is probably only 8 or 9 miles as the crow flies from Hunts).

Felixstowe to grafham on google maps is easy to get a distance on but the wash to grafham is a lot more differcult.

jeffers :- "I remember several oocasions over the last couple of years when the wind suddenly filled in from nothing to a steady F3-4 in a matter of minutes".

Remember jeffer`s that this happens sometimes but a sea breeze tends to happen 3 out of 4 days regularly not just several occasions over the last couple of years.

Also the sea breeze has to be considered a local to the coast breeze & if it was a consitant inland breeze would & should have a differant name.

This is what I mean, because Hunts is a long way inland the conditions have to be right for the breeze to make it to us. Generally if the gradient wind is from the east and it gets reinforced by the sea breeze (and it is a hot day). These conditions don't happen very often...

I'm not convinced the term 'sea breeze' is correct for inland waters. 

Jim C is quite right about heating and gradients.  Plymouth is a great example - on a hot day the south facing slopes of Dartmoor heat, air rises and cooler air is sucked in off the sea giving the sea breeze.

Inland waters probably get a similar effect from local features.  I have heard that Datchet can get some type of 'sea breeze' (probably should call it thermally induced breeze) from the heating of the tarmac at Heathrow. 

Can't think what local feature at Grafham or Hunts would induce this effect, but i really can't believe that its the sea breeze from the Wash.  The flow cell for that air movement would cover most of East Anglia.

At risk of raising an old topic.  Sea breezes do occur over Northern East Anglia under specific conditions.  They do tend to flow from the wash direction, and tend to be more prevelant here and make it further inland than elsewhere in the country as suface friction is low (have you noticed how flat it is?) and the massive thermal effect of the huge fields and dark earth in mid spring (before the crop cover becomes to thick)

However the breeze is rarely very strong and doesn't last very long, usually 1500-1700ish.