Analysis of extreme water levels in the lower Chesapeake Bay

The lower Chesapeake Bay (LCB) experiences coastal flooding due to both tropical and extratropical systems. Water levels produced from these events is often called storm surge; however, storm tide (a combination of the predicted tide, storm surge, and local anomaly), is a more appropriate term. Storm tide levels vary spatially in the LCB. Here we assess this spatial variability relative to local datums, such as highest astronomical tide (HAT) and mean lower low water (MLLW). We determined whether there was any difference in hours above HAT between each of our stations for each storm. We revealed a trend that central bay stations, such as Windmill Point and Lewisetta, spend more time above HAT than the stations in the south bay and Washington. The maximum water level above MLLW and HAT was determined for each station and storm and then analyzed for spatial trends. We found that, in general, central bay stations have smaller maximum heights above HAT than the south bay stations. Washington does not follow the pattern of other large tidal-range stations, such as the south bay stations.