Can someone explain this tide?

[BaNZ]

West coast tide have like a mini low tide and another super low tide. Why is it like that?

East coast is consistent with the peak and trough.

[oldmansurfer]

Is it like that all year around? I am not sure the exact reason why but in Hawaii we have both those patterns and more over the course of a year. It has to do with the position of the sun a little bit of the moon and the rotation of the earth. Tides behave differently facing the rotation of the earth verses facing away from the rotation of the earth.

[steveylang]

http://home.hiwaay.net/~krcool/Astro/moon/moontides/

Why aren't the Atlantic and Pacific coast tides the same?
"The nature of tides on the Earth's oceans is very complex. The oceans are, of course, being periodically 'forced' by a number of tidal sources including the Moon and the Sun, but this forcing has a number of different periods and harmonics. The two dominant periods are sue to the Sun and Moon, these are referred to as the S1 and M2 'modes' which have roughly 12 hour periods because they raise TWO water tides on the ocean diametrically opposite each other. But, for a variety of reasons, any given port will not have two high and two low tides each day; also called 'semi-diurnal tides'. A careful monitoring of the tides at any port for several years will show that in addition to the major modes, there are as many as 300 minor or 'harmonic' modes as well.

The World Ocean is a complex dynamical system. The natural velocity of a water disturbance depends on the depth and salinity of the water at each point it passes. When bodies of land circumscribe bodies of water, they produce a collection of resonating systems that favor water oscillations with certain frequencies over others. From among the 300+ harmonics that can be measured, every port and coastal location has its own unique signature depending on its latitude, longitude, water depth and salinity. The result is that the 'two high two low' tide rule can be strongly modified so that the time between successive high tides can be greater than or less that 12 hours in many cases. The result is that for some locations, there can be days when only one high tide occurs. Looking at the Atlantic and Pacific Coast tide tables for 1995, the data for the various 'Standard Ports' showed that virtually all days had two high tides and two low tides in San Diego, San Francisco, New York and Charleston. There were, however a few days every few months when only a single high tide occurred." - Dr. Odenwald's ASK THE ASTRONOMER

[BaNZ]

I understand there's low and high tide and it's complex. But I've not see anything like the ones in California. I've surfed in many different places and Cali is the only one I see shows a graph like that. Just thought it is a little odd.

[Big H]

Tides and tidal coefficients follow the moon....spring tides have the highest differences and neap tides the least. Some days we have a high low tide and a low low tide, some days the tides are a few dozen centimetres apart, a couple of weeks later you can have a difference of two meters 6 hours apart. Usually we get two highs and two lows, but every now and then we get one low and two highs.......DTC's answer in your second thread about the same thing addressed your specific question well enough.

I've read up on this somewhat; I was satisfied knowing that these were normal occurrences that were regulated and patterned by the moon/earth relationship.....didn't get too deep into the reasons why and the forces that shape the tides. Here are some more links for concepts that are surf useful like coefficients and what that means for tidal currents.

In short, if tidal coefficients are high on a given day and the swell is up, it can be hairy and I think twice about certain spots that normally have stronger currents as they can be unmanageable on these kinds of days. At the least I know that I'm in for a workout. Also, if a spot only works at a small window of tide level, bigger days will have a smaller and shorter window of "good" surfing time. Contrast that with a benign neap tide; I have a couple of spots that work for the tide levels of the usual neap low high tide to high low tide time period as the spot will work all day long and not really change.


https://oceanservice.noaa.gov/facts/springtide.html

https://tides4fishing.com/tides/tidal-coefficient

https://oceanservice.noaa.gov/education ... ur02a.html

[oldmansurfer]

Is it like that all year around? I am not sure the exact reason why but in Hawaii we have both those patterns and more over the course of a year. It has to do with the position of the sun a little bit of the moon and the rotation of the earth. Tides behave differently facing the rotation of the earth verses facing away from the rotation of the earth.

I messed up on this it is the moon and a little bit of the sun.

[RinkyDink]

More info than you probably wanted on the tides. It's interesting info though.