An inquisitive Surfline user writes . . .
“Can you explain why tides often go very high, but rarely go that far negative?”
I was curious of this as well, and after doing some searching and talking among the forecast team, this is what we gathered…
For the tide scale, the zero foot mark is set at the lowest end of the scale; with the average level of low tide (Mean Low Water or MLW) at a specific place over a 19-year period. Therefore, the tide levels will usually have a much greater range through the positive foot scale, with only an occasional dip just below 0′ in the negatives. This scale system was most likely set in place for mariner purposes, as well as making the scale mainly one sided and easier to understand (ie. Having the bottom out low tide around 0′, and observing just how much water fills into the coast/harbors).
Cheers,
Jonathan Warren