Sea Breezes

[William Grimsley]

Hi there,I have a question about sea breezes, they are happening quite often here in Newton Poppleford seen as I am near the sea. I understand the basic concept of that they form when the air temperature has to be higher than the sea temperature and that the wind has to be quite light but I am uncertain about what strength the wind cannot exceed for it to form.

 

There is currently one on the coast but not here and I was wondering how long on average it takes for a sea breeze to track from the coast to a few miles inland?

 

Have I identified all the ingredients or is there more to the sea breeze formation than that?Thanks,William

[johnholmes]

Hi there,I have a question about sea breezes, they are happening quite often here in Newton Poppleford seen as I am near the sea. I understand the basic concept of that they form when the air temperature has to be higher than the sea temperature and that the wind has to be quite light but I am uncertain about what strength the wind cannot exceed for it to form.

 

There is currently one on the coast but not here and I was wondering how long on average it takes for a sea breeze to track from the coast to a few miles inland?

 

Have I identified all the ingredients or is there more to the sea breeze formation than that?Thanks,William

 

 

hi William

Somewhere in the Guides is an article I did some years ago which you may find helpful.

Your basic idea T overland exceeding T over the sea is correct as is your comment re wind strength. A lot depends on the topography between you and the coast. Can any funnelling effects occur, is there any high ground that may hinder or increase the flow off the sea or the land, type of soil in the area between yourself and the sea. 

As the sea breeze develops on the coast it ALWAYS veers with time, this is due to the Coriolis effect, Google that or go to this site (sorry since I got my new pc I can never find things-will post when I find it)

If this is not enough please pm me and I will try to answer things for you

[William Grimsley]

hi William

Somewhere in the Guides is an article I did some years ago which you may find helpful.

Your basic idea T overland exceeding T over the sea is correct as is your comment re wind strength. A lot depends on the topography between you and the coast. Can any funnelling effects occur, is there any high ground that may hinder or increase the flow off the sea or the land, type of soil in the area between yourself and the sea. 

As the sea breeze develops on the coast it ALWAYS veers with time, this is due to the Coriolis effect, Google that or go to this site (sorry since I got my new pc I can never find things-will post when I find it)

If this is not enough please pm me and I will try to answer things for you

I have a lot of hills to the S of here where the coast is, though it seems like the sea breeze happens first and finishes last in the valley and not up here on the hill.

[johnholmes]

I have a lot of hills to the S of here where the coast is, though it seems like the sea breeze happens first and finishes last in the valley and not up here on the hill.

 

the valley will see the breeze first and last as you say, simple physics really that it happens that way?

[William Grimsley]

the valley will see the breeze first and last as you say, simple physics really that it happens that way?

It is interesting as I have finally got a sea breeze now. The wind seems to go very calm and then slowly pick up from the SE/SSE/S/SSW/SW. Sometimes though the wind comes from the land which is the land breeze.All I was really wanting to know is that if anything instead of just temperature, wind speed and topography would limit sea breeze development. I don't really understand the bit about the type of soil?

[johnholmes]

It is interesting as I have finally got a sea breeze now. The wind seems to go very calm and then slowly pick up from the SE/SSE/S/SSW/SW. Sometimes though the wind comes from the land which is the land breeze.All I was really wanting to know is that if anything instead of just temperature, wind speed and topography would limit sea breeze development. I don't really understand the bit about the type of soil?

 

different soils will heat at differing rates so some areas will get warmer more quickly thus the temperature above them will do so as well. This will create a quicker and larger difference land to sea so the sea breeze might come in earlier over say a sandy soil rather than a clay soil. A rather similar effect occurs in marginal sea breeze situations when the sand is either wet or dry. Hence the sometimes quoted comment that the sea breeze comes in with the tide-not strictly true but an element of truth in it. Did you find the Guide I mentioned?

[William Grimsley]

different soils will heat at differing rates so some areas will get warmer more quickly thus the temperature above them will do so as well. This will create a quicker and larger difference land to sea so the sea breeze might come in earlier over say a sandy soil rather than a clay soil. A rather similar effect occurs in marginal sea breeze situations when the sand is either wet or dry. Hence the sometimes quoted comment that the sea breeze comes in with the tide-not strictly true but an element of truth in it. Did you find the Guide I mentioned?

Oh I see so basically the drier and dustier the soil is, the quicker the sea breeze will move over the land and if the ground is drier then it will come in sooner. So, if the tide comes in in the morning then the sea breeze will come in with it possibly? Also, I can't find this "Guide"?

[johnholmes]

Oh I see so basically the drier and dustier the soil is, the quicker the sea breeze will move over the land and if the ground is drier then it will come in sooner. So, if the tide comes in in the morning then the sea breeze will come in with it possibly? Also, I can't find this "Guide"?

the link

http://forum.netweather.tv/forum/24-learning-about-weather-and-meteorology/

scroll down until you find the guide?

[William Grimsley]

the link

http://forum.netweather.tv/forum/24-learning-about-weather-and-meteorology/

scroll down until you find the guide?

Oh yes I've found it. Thanks.

[William Grimsley]

A very interesting post, John. All that was on your post was basically what I knew already but in greater detail. It didn't mention anything to do with the ground, though.

[Lauren]

William, we often holiday in Colyford. We often notice that what we experience on the hill is often quite different to what you experience just down the road and as you say the breeze follows the valley. We stopped off in Newton Poppleford for lunch one day and noticed the sharp breeze seemed to arrive there several hours after we had it in Colyford.

 

Don't know the science behind it, but I have experienced what you have.

[East_England_Stormchaser91]

Basically, a sea breeze will form when winds are light, I.e no real prevalent direction under a high pressure. The higher the contrast in temperature from land to sea, the stronger the sea breeze will be.

Also, flat areas tend to get influenced by them a lot. Here in Peterborough, we always get the sea breeze from the wash some 30 odd miles away. After all we are some 2-3 metres below sea level around here in some parts!

[William Grimsley]

William, we often holiday in Colyford. We often notice that what we experience on the hill is often quite different to what you experience just down the road and as you say the breeze follows the valley. We stopped off in Newton Poppleford for lunch one day and noticed the sharp breeze seemed to arrive there several hours after we had it in Colyford.

 

Don't know the science behind it, but I have experienced what you have.

That's interesting and thanks for visiting Newton Poppleford! Can you recall a date?

Basically, a sea breeze will form when winds are light, I.e no real prevalent direction under a high pressure. The higher the contrast in temperature from land to sea, the stronger the sea breeze will be.Also, flat areas tend to get influenced by them a lot. Here in Peterborough, we always get the sea breeze from the wash some 30 odd miles away. After all we are some 2-3 metres below sea level around here in some parts!

Yes, I understand that. It does seem that river valleys seem to be more affected as they are at a lower height and are flat.

[Lauren]

That's interesting and thanks for visiting Newton Poppleford! Can you recall a date?

Yes, I understand that. It does seem that river valleys seem to be more affected as they are at a lower height and are flat.

 

Erm, it must have been sometime in late March/early April 2013. Whatever the Easter weekend was.

[William Grimsley]

Erm, it must have been sometime in late March/early April 2013. Whatever the Easter weekend was.

Yeah, I think I remember something then.

[East_England_Stormchaser91]

Yeah, I think I remember something then.

The last time I saw snow !

[William Grimsley]

Hmmm, not getting a sea breeze today even though the wind isn't that strong. It's very warm and there are sea breezes on the coast but not here. What's stopping them?

[knocker]

Well your temp is only 20C with a NE wind gusting 11mph so perhaps the pressure differential isn't strong enough give a sea breeze far inland.

[William Grimsley]

Well your temp is only 20C with a NE wind gusting 11mph so perhaps the pressure differential isn't strong enough give a sea breeze far inland.

So how much pressure differential would I need? A good 0.5 hPa?

[knocker]

So how much pressure differential would I need? A good 0.5 hPa?

 

To be honest I've no idea but you have to take other factors into account such as the NE wind that wouldn't help if the onset of a sb is marginal. I would be surprised if 20C warm enough to create one inland but you would know better than me being familiar with the area.

[johnholmes]

I think maybe you are not understanding pressure differential William, forgive me if I am wrong though.

This is, I think, explained in the Guide I referred you to.

The link below shows the surface chart and the isobars, the pressure difference is the gradient or geostrophic wind ( use Google to help explain that or again the Net Wx Guides-still cannot find the link I wanted the other day yet), that is the speed of the flow at 2000ft (assumed), the distance between the two isobars over your area and the nearest coast.

Hard to measure on the chart shown so the Met Fax below it is a better way as it does show the scale in the top left. It is only every 6 hours though.

http://meteocentre.com/analyse/map.php?hour=0〈=en&map=UK

http://www.weathercharts.org/ukmomslp.htm

A VERY rough rule is less than 20 knots and a sea breeze with the other factors mentioned in the Guide suggests a sea breeze is possible.

hope this helps?

[knocker]

This is the only link I've found John. If I may add as usual an excellent explanation.

 

http://forum.netweather.tv/topic/38567-the-mechanism-behind-a-sea-breeze/

Edited June 17, 2014 by knocker

[johnholmes]

thanks mate but it is a web site that was started by another ex senior forecaster, a veritable treasure trove for objective weather data. I will find it eventually and bookmark it again.

[johnholmes]

found it at last

http://weatherfaqs.org.uk/

a really useful site for anyone but it is really for William in the context of this.

 

sods law!

nowt about sea breezes, never mind.

 

Have you seen my above post please William?

Edited June 17, 2014 by johnholmes

[knocker]

Ah didn't realise you were looking for that site John.

 

For a simple explanation of the pressure gradient.

 

http://cimss.ssec.wisc.edu/wxwise/seabrz.html