Tide gauges and satellites
Sea level along the coast
Each tide gauge's water level with the tide taken out, averaged over a week and compared with its usual level (its average over the past year). The ribbon lies on the sea along the coast, the coast itself being that usual level, and reaches out to sea as far as the sea stands from it: warm where higher, blue where lower. Each gauge's reading is a tick ending in a dot; between gauges the ribbon is filled in from the nearest two, except across gaps over 600 km. An island's gauge is a disc on the sea, as wide as its sea stands from usual. Switched to ten days, the timeline shows the water above the predicted tide hour by hour, as a storm's surge shows. Offshore, faintly: satellite sea level, compared the same way and smoothed; it still includes the seasons. How it is worked out
Six months along the coast
Each lane is one tide gauge, Eastport at the front and Port Isabel at the back, spaced as they are along the coast; time runs left to right. Points above the glass sheet are days when the sea stood higher than usual, points below it lower. Drag to turn the view; the replay above shows it day by day.
Tide gauges: NOAA CO-OPS. Satellite sea level: NOAA CoastWatch, from RADS; Sentinel data courtesy of the Copernicus Programme; generated using AVISO+ products.
Why the sea stands higher or lower here
Along the Gulf and Atlantic coasts the sea stands higher or lower for days to weeks with the wind along the shore and the air's pressure, with changes in the Gulf Stream offshore, and with the seasons. A storm's surge comes and goes in hours: switch the timeline to ten days to see the water above the predicted tide hour by hour. This page shows what was measured, as it was measured, and does not say which cause is which; it does not forecast what comes next.