Figure 11. This graph shows the difference from the observed tide (red) and predicted tide (blue). The difference is the storm surge amount (green). Tides exceeded the 12-foot level 5 times in 4 days at the Portland Harbor tide gauge. Just before midnight on February 25, 2010, the Portland Tide Gauge recorded a 4.37 foot surge. Since 1912, the highest surge recorded in Portland (at high tide) was 4.6 feet on March 3, 1947. The Blizzard of February 7, 1978 had a 3.5 foot surge but it occurred during an extreme high tide and holds the highest record for water levels - 2 feet above this storm. Tides ran above normal for 9 days: February 24 - March 4, 2010. Data courtesy of the National Oceanic and Atmospheric Administration. Graphic by S. M. Dickson, MGS.
Higher resolution PDF image of Figure 11.
Last updated on July 6, 2011