Effect Of Wind On Tides

[JohnK]

So today we have a strong southerly and I think high tide has come at least an hour earlier than the predicted time at Potter (four hours after Gorleston)

I would have expected the opposite as I thought a southerly pushed the water up the English Channel making tides here later.

What have I misunderstood? “Everything” is a viable answer

[Simon]

No idea if my thoughts are correct, hopefully someone more knowledgeable will come along and answer this.

could a strong southerly of held back the ebbing tide so actual low water was higher than predicted, thus high water at Potter was achieved earlier but with less incoming water. Plus add to this recent rain fall working its way in to the rivers.

also if the southerly wind is stronger than the flood tide would that not push the water somewhere, perhaps up the Bure quicker.

 

[Vaughan]

Anyone who understands and can predict the tides on the Broads could make a lot of money!

We are just coming off springs at the moment so normal tides are at their highest anyway. Yesterday there was a fairly deep depression over middle England which was causing the southerly wind.

What causes the surge tides is when a storm goes across the coast of Norway and then stays there for a bit, causing strong north west winds which funnel the water down the North Sea where it is constricted as it gets to the Channel and so piles up on the East Anglian coast. If this happens during spring tides then you will have floods.

On this occasion, I believe it is caused more by the heavy rainfall over the county which is trying to get away, down from the headwaters of the rivers, but is being held up by the high tides. This more like the Somerset Levels, if you like.

 

[JohnK]

Anyone who understands and can predict the tides on the Broads could make a lot of money!
We are just coming off springs at the moment so normal tides are at their highest anyway. Yesterday there was a fairly deep depression over middle England which was causing the southerly wind.
What causes the surge tides is when a storm goes across the coast of Norway and then stays there for a bit, causing strong north west winds which funnel the water down the North Sea where it is constricted as it gets to the Channel and so piles up on the East Anglian coast. If this happens during spring tides then you will have floods.
On this occasion, I believe it is caused more by the heavy rainfall over the county which is trying to get away, down from the headwaters of the rivers, but is being held up by the high tides. This more like the Somerset Levels, if you like.
 

Thanks Vaughan,
It would be fascinating to have a few tidal gauges dotted around the broads and compare actual to predictions and try and predict the deviations.
Especially if you compare Gorelston predicted to actual (for which I think there might be a gauge) and see how much extra deviation there is on the broads.
Or I’m very sad

I keep thinking about writing a smartphone app to try to do tides on the broads (predicted only to start with) but my programming ability falls well short.
I might try to create an Excel sheet to do it. That’s definitely doable.

[inserttitle]

John,

Some gauges here:

https://flood-warning-information.service.gov.uk/river-and-sea-levels?location=River Thurne at Repps

eg for Potter: https://flood-warning-information.service.gov.uk/station/6217?direction=u

--

[JohnK]

John,
Some gauges here:
https://flood-warning-information.service.gov.uk/river-and-sea-levels?location=River Thurne at Repps
eg for Potter: https://flood-warning-information.service.gov.uk/station/6217?direction=u
--

Awesome! Thanks for that. Didn’t know they existed for inland waterways.

[marshman]

Vaughan is getting pretty close to the mark, but he is right, there are just too many differing factors, all of which can come into play. And if you could try and write an app and build in the differing variables it would probably still be wrong - for no accountable reason!!

Although someone pooh poohed it some time ago, you do need to take into account pressure - at the moment pressure is low . Sit a high pressure over the top  of us for a few days and watch it start to fall! The water that is!

But at the moment, as he says it is all to do with the amount of fresh water pouring out of the middle of Norfolk - Norfolk is a big area to drain and the flatness of the land (generally! ) means it only goes slowly. And of course, it can only drain depending on the tides in the North Sea - when they are high or ish, where can the water go??

Out there, you have to remember that the Straits of Dover are a major bottle neck in the overall scheme of things but very very strong SW winds can just blow all the water out of the North Sea - down in N Kent during the hurricane of 1987, my boat was very, very secure! The boat sat on the mud all day and night whilst it was blowing as the tide never came in!!!!

 

 

[LondonRascal]

A very nice site is http://www.gaugemap.co.uk/

I prefer it's layout and data (scrubbed from the Environment Agency) but presented well. Just search for the local gauge such as Hoveton Broad:

[JohnK]

I’m thinking I’ll start with tides (just predictions read from t’internet)
Then add flows maybe with a graphic to show what rivers are flowing which way.
Then add gauges.
Then based on gauge data (read from t’internet) try and predict errors comparing gauge to actual (heights and times) when looking at wind speed, direction and air pressure.
I know it won’t be perfect (probably not even close) but I enjoy that sort of mental challenge.
I did try app building but it’s much too like “proper” programming for me so I’m now thinking Excel - possibly via office 365 to make it shareable.

[Guest]

3 hours ago, Vaughan said:

Anyone who understands and can predict the tides on the Broads could make a lot of money!

We are just coming off springs at the moment so normal tides are at their highest anyway. Yesterday there was a fairly deep depression over middle England which was causing the southerly wind.

What causes the surge tides is when a storm goes across the coast of Norway and then stays there for a bit, causing strong north west winds which funnel the water down the North Sea where it is constricted as it gets to the Channel and so piles up on the East Anglian coast. If this happens during spring tides then you will have floods.

On this occasion, I believe it is caused more by the heavy rainfall over the county which is trying to get away, down from the headwaters of the rivers, but is being held up by the high tides. This more like the Somerset Levels, if you like.

 

King Canute step forward please  iv tried n now i just go with the flow 

[TheQ]

We've had a northerly / north westerly for the last day, pushing tide down the north sea holding the tide level up for the broads and turning the tide to incoming early

This evening through tomorrow the forecast is for a South easterly which is fairly strong, through to Saturday a southerly.

So from tonight the tide should flow out much easier and by Saturday may be late to turn to incoming.

[oldgregg]

I’m thinking I’ll start with tides (just predictions read from t’internet)
Then add flows maybe with a graphic to show what rivers are flowing which way.
Then add gauges.
Then based on gauge data (read from t’internet) try and predict errors comparing gauge to actual (heights and times) when looking at wind speed, direction and air pressure.
I know it won’t be perfect (probably not even close) but I enjoy that sort of mental challenge.
I did try app building but it’s much too like “proper” programming for me so I’m now thinking Excel - possibly via office 365 to make it shareable.

Or if you can work out the model then perhaps someone might work with you on the other bit...

Sent from the Norfolk Broads Network mobile app

[marshman]

John - I admire you!

But me I would look out of the window, say its up a bit or down a bit, then jump in my boat and have a potter around one of unquestionably the best bit of the Broads!! 

Sod the App....!!!!!

[JohnK]

John - I admire you!
But me I would look out of the window, say its up a bit or down a bit, then jump in my boat and have a potter around one of unquestionably the best bit of the Broads!! 
Sod the App....!!!!!

Haha, I like technology too much. Why look out of the window when I can check the camera?
I genuinely enjoy creating that sort of stuff. One of the most interesting jobs I picked up in the last couple of years was to data model the chemistry in a 50,000 tonne doughnut shaped pile of gypsum. I fully accept how sad that sounds. But it keeps me out of trouble and pays for toys

[Guest]

JohnK the Acle gauge I find the “cleanest” data. 

[Chelsea14Ian]

6 minutes ago, JohnK said:

 

Haha, I like technology too much. Why look out of the window when I can check the camera?
I genuinely enjoy creating that sort of stuff. One of the most interesting jobs I picked up in the last couple of years was to data model the chemistry in a 50,000 tonne doughnut shaped pile of gypsum. I fully accept how sad that sounds. But it keeps me out of trouble and pays for toys

 

How jam in that bad boy?

[Chelsea14Ian]

Silly Billy should say how much jam in that bad boy?

[JohnK]

JohnK the Acle gauge I find the “cleanest” data. 

The Repps gauge is about 100 meters from me so we’ll be starting with that one . I can see the height if I don’t believe it.
Historic predicted and tide data I think I can access. But I’m not sure where to get historic weather data (wind speed, direction and air pressure). Ideally data tables.
Any ideas?

[Guest]

The Repps one always seems to be all over the place but it may be exactly that local variability you are looking for. 

Historic data must be possible - is there a met office archive. Data is $$$ though these days.

[JohnK]

The Repps one always seems to be all over the place but it may be exactly that local variability you are looking for. 
Historic data must be possible - is there a met office archive. Data is $$$ though these days.

Hmmm, the Repps one is right next to a big pump so maybe that’s having an impact. I’m not modelling that