I am looking to my sailing community for some help. Are there ny rules of thumb of guidelines on how much wind holds back tide.

Specifically, I amd concerned with the tide height in the Mersey tonight at 10.10 m, the wind has now swung to the SE and predicyed to move to S, so blowing against the tide holding it out, wind Guru gives me between 8 and 15 knots depending (West Kirby).

Thanks in anticipation.

Alan,

Have you just lit up a funny fag?

No rule of thumb I am afraid.
But the science goes like this - the tidal current distribution with depth is such that the current flows at full predicted velocity at the surface and reduces in a non-linear way until it reaches zero at the seabed.
When you have a wind acting against this current, the current velocity at the surface will reduce by a certain amount depending on the wind strength or may even flow in the opposite direction. Up to a certain wind strength the flow below the surface will increase and there will be no resultant effect on tide height, but at a critical wind strength (which depends at a particular location on wind speed, tidal current velocity, water depth etc) the shear forces in the water column will resist this increased flow below the surface and the heigh/low water time and range will start to be effected.
So get out your tidal atlas, 3d terrain model of the Mersey estuary and some info on the preset wind pattern and work it out. wrt the shear properties of water the kinematic viscosity of fresh obviously varies with temperature and salinity but will be in the range of 1.30641-1.35383 for water temp of 10deg C.
Hope this helps.

Not at all. If the tide breaches the sea wall at Liverpool there is a possibility of flooding the basements of the buildings, with consequential impact to the businesses, I am trying to assess the risk that we may have to invoke contingency for our Liverpool office. 

All information is good information, even from the Merlin site :-)

It is part of what I do during the day to pay for my hobby.

Thanks Neptune. So I'll just get the man to put the sand bags out then ;-)

The Coast guard and or the Mersey River Authorities will know if a tidal surge is expected but it is well past Springs and it's hardly a gale is it.

Consider then with  all this risk analysis stuff Nelson's problem at Tafalgar brought up  to date.
Nelson: Order the signal Hardy!

Hardy: Aye! Aye! Sir!

Nelson: Hold on that's not what I dictated to the
signal officer,
what's the meaning of this?

Hardy: Sorry sir.

Nelson: (reading aloud) England expects every person to
do his duty,
regardless of race, gender, sexual orientation,
religious persuasion or
disability. What gobbledegook is this?

Hardy: Admiralty policy I'm afraid Sir.
We are an equal opportunities employer now and we have
had the devils
own job getting 'England' past the censors lest it be
considered racist.

Nelson: Gadzooks Hardy - hand me my pipe and tobacco.

Hardy: Sorry sir, all naval vessels have been
designated smoke-free
working environments.

Nelson: In that - case break open the rum ration and
let us splice the
main brace to steel the men before battle.

Hardy: The rum ration has been abolished Admiral.
It's part of the government's policy on binge drinking.

Nelson: Good heavens Hardy, I suppose we'd better get
on with it. Full
speed ahead then.

Hardy: I think you'll find that there's a 4 knot speed
limit in this
stretch of water.

Nelson: Dammit man, we are on the eve of the greatest
sea battle in
history. We must advance with all dispatch. Report from
the crows nest
please.

Hardy: That won't be possible Sir.

Nelson: What?

Hardy: Health and Safety have closed the crow's nest,
Sir.
No harness and they say the rope ladder doesn't meet
regulations. They
won't let anyone up there until proper scaffolding can
be erected.

Nelson: Then get me the ship's carpenter without delay,
Hardy.

Hardy: He's busy knocking up a wheelchair access to the
fo'c'sle
Admiral.

Nelson: Wheelchair access? I've never heard of anything
so absurd.

Hardy: Health and Safety again sir.
We have to provide a barrier free environment for the
differently abled.

Nelson: Differently abled?
I've only one arm and one eye and I refuse to hear
mention of the word.
I didn't rise to the rank of Admiral by playing the
Disability Card.

Hardy: Actually sir you did. The Royal Navy is under
presented in the
areas of visual impairment and limb deficiency.

Nelson: Whatever next? Give me full sail, the salt
spray beckons.

Hardy: A couple of problems there too sir.
Health and Safety won't let the crew up the rigging
without hard hats
and they don't want anyone breathing in too much salt,
haven't you seen
the adverts?

Nelson: I've never heard such infamy.
Break out the cannons and tell the men to stand by to
engage the enemy.

Hardy: The men are a bit worried about shooting at
anyone Admiral.

Nelson: What? This is mutiny.

Hardy: It's not that sir.
It's just that they are afraid of being charged with
murder if they
actually kill anyone. There are a couple of legal-aid
lawyers on board
watching everyone like hawks.

Nelson: Then how are we to sink the French or the
Spanish?

Hardy: Actually sir we're not.

Nelson: We're not?

Hardy: No Sir. The French and the Spanish are our
European partners now.
According to the Fisheries policy, we shouldn't even be
in this stretch
of water. We could get hit with a claim for
compensation.

Nelson: But you must hate a Frenchman as you hate the
devil?

Hardy: Not any more sir. We must be inclusive in this
multicultural age.
Now put on your Kevlar vest; it's the rules and it
could save your life.

Nelson: Don't tell me, Health and Safety.
Whatever happened to rum, sodomy and the lash?

Hardy: As I explained sir, rum is off the menu and
there is a ban on corporal punishment.

Nelson: What about sodomy?

Hardy: I believe that is now legal sir.

Nelson: In that case - Kiss me Hardy.

Actually, Springs may be over, but we are on stand-by for the highest tides in 25 years on the East Coast.  Inverness has already sandbagged the river banks.  Peak is HW at 100134A Sep.

Snap for the south east coast. Highest tide for years plus a south easterly pushing it up the Thames. I know a few yotties that are having to increase the lenght of their morring chains tonight

In the end no crisis, but a good story at the other end of the scale -

Some members of the Chanonry Club near Inverness spotted that the record high meant that there would also be a record low at 0830 on Saturday 9th.  On such rare occasions a sandbank in the very middle of the Inner Moray Firth is briefly exposed, about a mile from the shore in all directions.  Accordingly said group got up early, sailed out in a Wayfarer, and for half-an-hour played cricket.

Pictures were taken for proof and posterity of course.  The fun was only slightly derailed by the appearance in quick succession of the rescue helicopter, lifeboat and inshore rescue boat, alerted by someone on shore who, on seeing small figures jumping up and down on a sandbank, leapt rather too quickly to a conclusion. 

Page 3 of the Glasgow Herald today for photographs and the full story

There is a big difference between the highest astronomical tide for 4 years and the highest tide for 4 years. Last weekend witnessed the highest astronomical tide for 4 years, which is only 4cm higher than the highest last year. The conditions to be weary of are when large astronomical spring tides combine with low pressure systems coming in from the Atlantic. When this situation occurs tidal surges can increase water levels by meters and not cm. Because we had high pressure over the weekend, the only records going to be set were low water levels hence the cricket matches on sandbanks. However, keep a watchful eye on the weather over the 8/9/10 of October when an even larger astronomical tide is due, and check the Environment Agency website for details of any flood alerts issued.

Ahhh - Felucca weekend - batten down the hatches!!

The cricket story begs a few questions. How many cricketers can you get in a Wayfarer? and, How many Scotsmen (or ladies) can play cricket?

Four, and the wicketkeeper was a teddybear

If they were playing cricket they can't be true Scotsmen.  I mean, playing a sport immortalised by your sworn mortal enemy!

Actually cricket is quite a popular game in Hamish country - many games are crammed in to the traditional 3 days of summer:)

At Wormit we have a long tradition of playing sports on the sandbanks of the river Tay.
This years choice sport was Crownders - a kind of cricket, rounders and rugby mix. We have learnt from past mistakes and now inform the coastguard of our plans after our local Tesco called the big yellow bird to save the looneys on the river.
Incidently this has resulted in the annual award of the Golden helicopter trophy for c**k up of the year.

So it's true, Scots do walk on water! :)

With my capsize record it's a technique I am working on but have not yet perfected!!