Surge prediction

Agreed

PRV's quote got lost somewhere, but yes, NTSL is predicting a teatime surge well after HW.

Also the NTSL site gives subtractions for each port to convert from CD to OD.
 
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PaulJ said:
Does anyone know how tomorrow's predicted surge compares with the the predicted and actual surges in 2013? I am particularly interested in the Orwell.......
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We have just done the comparison using predictions for Sheerness and the data also for Sheerness that we saved in 2013 plus the tidal predictions for today and tomorrow. They predict that it should be a little (0.3m) lower than 2013 (but please don't rely on that for your location!). We used Sheerness because it is closer to where we are than the other ports listed. It is quite difficult to do, because the main part of the surge is predicted to be mid afternoon, near LW here. near HW the slope on the residual is very steep. It looks as if it's the HW early tomorrow morning that we should worry about, but we will be watching today's midday tide carefully.
 
There is now two and half hours to high tide here, and it does not look as if it is going to be especially high, no more than a good Spring high tide. I can't help feeling the media has whipped up a lot of unnecessary hysteria, which the council has acted upon, which in turn has given the media story credibility, ........ until the floods do not happen.

On the BBC news this morning they were evacuating people from Jaywick at 8.00am, and it was low tide. High tide is not until 1.00pm in Jaywick
 
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David

The latest figures for the surge are less then half a metre for this next tide. The peak surge is forecast at about 2.5 m at 9pm - luckily near to low tide. For tomorrow's early hours am tide the surge is forecast to be back down below a metre so entirely manageable.
 
DavidofMersea said:
There is now two and half hours to high tide here, and it does not look as if it is going to be especially high, no more than a good Spring high tide. I can't help feeling the media has whipped up a lot of unnecessary hysteria, which the council has acted upon, which in turn has given the media story credibility, ........ until the floods do not happen.

On the BBC news this morning they were evacuating people from Jaywick at 8.00am, and it was low tide. High tide is not until 1.00pm in Jaywick
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The point is that the surge prediction is just that, a computer generated prediction. Nature doesn't necessarily follow predictions. If the surge comes an hour or two early then there will be serious flooding, and if the agencies haven't acted (I doubt they act on media) then they are going to get hammered.
 
MikeBz said:
The point is that the surge prediction is just that, a computer generated prediction. Nature doesn't necessarily follow predictions. If the surge comes an hour or two early then there will be serious flooding, and if the agencies haven't acted (I doubt they act on media) then they are going to get hammered.
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They can't blame this non event on the computer, that is just buck passing. It maybe a prediction, but it is up to the "experts" to consider that if prediction is likely to happen before the media whipped up a lot of unnecessary hysteria, which the council has acted upon.
 
DavidofMersea said:
They can't blame this non event on the computer, that is just buck passing. It maybe a prediction, but it is up to the "experts" to consider that if prediction is likely to happen before the media whipped up a lot of unnecessary hysteria, which the council has acted upon.
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The surge "predicted" for Felixstowe for 8am was pretty much what arrived at 8am.
 
DavidofMersea said:
They can't blame this non event on the computer
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Errr, no and I didn't suggest that at all. What I said was "...the surge prediction is just that, a computer generated prediction. Nature doesn't necessarily follow predictions. If the surge comes an hour or two early then there will be serious flooding". They have to make allowance for the surge prediction being wrong, and it would only need to be an hour or two out for things to be pretty dire.

If Mersea council is acting on what they read in the media rather than all the data that is available then they have a serious problem.
 
Harwich Water Level
SensorHarwichLevelLarge.png


Please note: The times and heights shown are predictions only. All predicted heights are given relative to Chart Datum Harwich. Times and heights may be affected by meteorological conditions and deviations, under exceptional conditions, can amount to more than 1 metre. Harwich Haven Authority accepts no responsibility for any inaccuracies in this data.

Time Value Predicted Surge
13/01/17 13:10 3.88m 3.60m 0.28m
13/01/17 13:00 4.05m 3.75m 0.30m
13/01/17 12:50 4.17m 3.88m 0.29m
13/01/17 12:40 4.21m 3.98m 0.23m
13/01/17 12:30 4.25m 4.07m 0.18m
13/01/17 12:20 4.30m 4.12m 0.18m
13/01/17 12:10 4.37m 4.15m 0.22m
13/01/17 12:00 4.39m 4.15m 0.24m
13/01/17 11:50 4.35m 4.12m 0.24m
13/01/17 11:40 4.22m 4.06m 0.16m
13/01/17 11:30 4.08m 3.98m 0.11m
13/01/17 11:20 4.01m 3.87m 0.14m
 
MikeBz said:
The point is that the surge prediction is just that, a computer generated prediction. Nature doesn't necessarily follow predictions. If the surge comes an hour or two early then there will be serious flooding, and if the agencies haven't acted (I doubt they act on media) then they are going to get hammered.
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Or indeed if the surge comes a couple of hours late.....
 
DavidofMersea said:
They can't blame this non event on the computer, that is just buck passing. It maybe a prediction, but it is up to the "experts" to consider that if prediction is likely to happen before the media whipped up a lot of unnecessary hysteria, which the council has acted upon.
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This kind of judgement is surely best made after the event, not before it.
 
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