Shown in absolute terms as meters above mean lower low water (a MLLW) and as quantiles of the observed distribution of daily tide heights over the period (b). Much of the variation in absolute tide heights (a) is driven by large differences in the tidal range between gauges. Circled points show 24 counties where the estimated noticeable threshold can be statistically distinguished from the minor flood threshold at the 95% confidence level. Given the number of comparisons, six false positives would be expected. c Map showing the study area (shoreline counties along the Atlantic and Gulf coasts of the United States) and difference between estimated noticeable flooding thresholds and the minor flood threshold of the nearest tide gauge in terms of quantiles of the tide height distribution for counties where sufficient data exist to estimate a response function. Red dots show tide gauge locations.