Skew Surge and Storm Tides of Tropical Storms in the Delaware and
Chesapeake Bays for 1980 -2019
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. Distance from
Delmarva and relative location of storm track play a role in the
magnitude and variability of surge, although distance itself is not a
strong predictor. 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.