Skew Surge and Storm Tides of Tropical Cyclones in the Delaware and Chesapeake Bays for 1980–2019

John A Callahan,Christina L Callahan,Daniel J Leathers

doi:10.3389/fclim.2021.610062

Abstract

Coastal flooding poses the greatest threat to human life and is often the most common source of damage from coastal storms. From 1980 to 2020, the top 6, and 17 of the top 25, costliest natural disasters in the U.S. were caused by coastal storms, most of these tropical systems. The Delaware and Chesapeake Bays, two of the largest and most densely populated estuaries in the U.S. located in the Mid-Atlantic coastal region, have been significantly impacted by strong tropical cyclones in recent decades, notably Hurricanes Isabel (2003), Irene (2011), and Sandy (2012). Current scenarios of future climate project an increase in major hurricanes and the continued rise of sea levels, amplifying coastal flooding threat. We look at all North Atlantic tropical cyclones (TC) in the International Best Track Archive for Climate Stewardship (IBTrACS) database that came within 750 km of the Delmarva Peninsula from 1980 to 2019. For each TC, skew surge and storm tide are computed at 12 NOAA tide gauges throughout the two bays. Spatial variability of the detrended and normalized skew surge is investigated through cross-correlations, regional storm rankings, and comparison to storm tracks. We find Hurricanes Sandy (2012) and Isabel (2003) had the largest surge impact on the Delaware and Chesapeake Bay, respectively. Surge response to TCs in upper and lower bay regions are more similar across bays than to the opposing region in their own bay. TCs that impacted lower bay more than upper bay regions tended to stay offshore east of Delmarva, whereas TCs that impacted upper bay regions tended to stay to the west of Delmarva. Although tropical cyclones are multi-hazard weather events, there continues to be a need to improve storm surge forecasting and implement strategies to minimize the damage of coastal flooding. Results from this analysis can provide insight on the potential regional impacts of coastal flooding from tropical cyclones in the Mid-Atlantic.

Highlights

Coastal storms are a multi-threat natural hazard, often including heavy rain, strong winds, large waves, rip currents, and storm surge, all of which must be considered collectively when assessing risk and devising mitigation strategies
tropical cyclones (TC) that seemed to have little to no effect on water levels were left in the analysis provided that no other weather system was noticeably impacting the study region at that time, resulting in a near-zero skew surge for some storms
Higher storm tides are observed in the Delaware Bay than in the Chesapeake Bay as well as in upper bays compared to the lower bays

Summary

Introduction

Coastal storms are a multi-threat natural hazard, often including heavy rain, strong winds, large waves, rip currents, and storm surge, all of which must be considered collectively when assessing risk and devising mitigation strategies. Two of the largest estuaries in the United States, the Delaware and Chesapeake Bays, have been significantly impacted by strong TCs in recent decades, notably Hurricanes Sandy (2012), Irene (2011), and Isabel (2003). These two estuaries, located in the Mid-Atlantic coastal region, house ∼27 million inhabitants, a high density of metropolitan areas, transportation networks, industrial ports, and currently are under active development (Sanchez et al, 2012; Chesapeake Bay Program, 2020). Coastal flooding has been deemed an important natural hazard in this region (Boesch et al, 2018; Delaware Emergency Management Agency, 2018) and can have a tremendous economic impact on current and future waterfront areas (Li et al, 2020)

Objectives

Methods

Results

Conclusion