Florida

Florida's tidal coast splits cleanly into two distinct signals — the Atlantic east coast and the Gulf of Mexico west coast — with the mixed-zone Florida Keys at the southern hinge. The Atlantic coast from Jacksonville south through Daytona, Cape Canaveral, and Miami runs cleanly semidiurnal with a small-to-modest mean range, around 0.7 metres at Miami climbing toward 1.4 metres further north. The Gulf coast from Pensacola through Tampa Bay south to Naples runs a strongly diurnal signal — one high and one low per day most of the lunar month — with a small mean range near 0.4 metres. The Keys sit between the two and produce the most irregular pattern in the continental US, with daily asymmetry that can shift week to week. Hurricane season runs June through November and storm surge during a tropical landfall can override the harmonic signal completely; the National Hurricane Center is the authoritative real-time source then. NOAA CO-OPS runs the authoritative gauge network and harmonic predictions for the entire Florida coast, which on a normal-weather day produce navigation-grade accuracy.