# Tides



## duncs (Sep 8, 2008)

Just wondered, is there an equation to calculate differentiation in HW levels(as per UK Hydrographic) at different baro pressures? I am fully aware that low pressure gives higher than predicted tides.



Rgds
Duncs


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## seaman38 (Mar 16, 2016)

duncs said:


> Just wondered, is there an equation to calculate differentiation in HW levels(as per UK Hydrographic) at different baro pressures? I am fully aware that low pressure gives higher than predicted tides.
> 
> 
> 
> ...


There is, but a long time since used it, try The Meteorological Office in Exeter, their details will be on the net, but perhaps someone on here has a better memory than me.

Not opening a ferry service are you? (Smoke)


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## howardang (Aug 3, 2008)

duncs said:


> Just wondered, is there an equation to calculate differentiation in HW levels(as per UK Hydrographic) at different baro pressures? I am fully aware that low pressure gives higher than predicted tides.
> 
> 
> 
> ...


Tides are predicted using a standard pressure of 1013 mb. A change of pressure of 1 mb (up or down) causes a change of tide level by plus or minus 1 cm.

I hope that answers your question.

Howard


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## duncs (Sep 8, 2008)

Howard,

It does indeed answer my question. Many thanks for that info.


Rgds

Duncs


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