Last Saturday, was the full moon – which occurred at perigee. Yesterday was the Vernal Equinox. According to my office calendar (which carries an overabundance of information), the highest high tide for the month, and the lowest low tide in Southern California occur today (23:13 and 05:57 PDT respectively).
If I recall my college astronomy correctly, tidal forces have to do differential gravitational pull between two different bodies (or equally between two ends of the same body). I also recall that it increases and decreases on the cube of the distance – as opposed to the square of the distance for single body gravitation. Alas, I don’t recall the details; and my Astronomy text book was one of the books lost when the water heater in Oceanside decided to assume the roll of waterfall. So, I don’t have the math readily at hand (or at least more readily than pouring through a number of web pages to make sure I’m getting the info I’m looking for).
But, I still have a very strong suspicion that there is more than coincidence involving at least the tides and the lunar phase. But I would not by surprised that the equinox also plays a part – either by making the tides a bit more extreme, or by moving the date away from the actual full moon and lunar perigee.
Alas, since my real work calls (at least a bit) I must leave this – undoubtedly well studied and understood – pondering to wait.