Figure 9. Hourly averaged water levels, referenced to Mean Sea Level, for the Portland, ME tidal station for the month of June 2009. Predicted tidal elevations are represented by the blue line, while observed hourly averaged data is represented by red "+" signs. The difference between the observed and predicted water levels (marked by green "x" signs) is considered to be "surge." The highest exceedance from predicted values was 1.2 feet, and occurred on June 29, 2009. Data courtesy of NOAA's Tides & Currents website.
Last updated on April 30, 2012