In these cases, CHO is also an offshore observation, but this occurs after the tropical cyclone has previously made landfall. No eye was visible on thermal infrared imagery for Lili at the time of landfall. Hurricane Opal in 1995 (Figure 2e) is an example of this type. Suite 250 Therefore, CHO − COO = 1 and the last observation before CHO is utilized as landfall. 2006). Both were large, powerful storms that hit in vulnerable locations. Type 4 events have multiple landfalls. Miami Beach, Florida, where the continental shelf drops off very quickly, RSE values for the linear model at 18 h before landfall only fell to 0.9431. Tropical Storm Matthew in 2004 (Figure 2k) provides such an example, as the storm made landfall in south Louisiana, near Cocodrie, Louisiana, and then continued to approach Frenier, the location of peak storm surge, for the next 5 h. Matthew’s center of circulation was inland during these 5 h but was still able to approach Frenier, as this small village is located near the westernmost portion of Lake Pontchartrain. Hurricane Danny followed a similar track as Lili, as both storms moved northwest from the central Gulf of Mexico and made landfall just west of Vermillion Bay, Louisiana. The system then continued moving northeastward, making its final landfall along the Alabama coast (Unisys 2012). In these cases CHO is also equal to COO. As the radius of maximum winds was 28 km (15 n mi), Andrew’s eyewall made a direct hit on the location of peak surge, because the distance from the center of the eye to the location of peak surge was less than double the radius of maximum winds (National Hurricane Center 2012a). Other physical parameters may include the geometry of the coastline and bathymetry of water near the coast, which may amplify the buildup of water that is already displaced by the wind. By continuing to use our website, you are agreeing to, Bulletin of the American Meteorological Society, Journal of Applied Meteorology and Climatology, Journal of Atmospheric and Oceanic Technology, National Institute of Standards and Technology 2013,,,,,,,,,,,,,,, An Empirical Analysis on the Relationship between Tropical Cyclone Size and Storm Surge Heights along the U.S. Gulf Coast, Distinct Mechanisms of Decadal Subsurface Heat Content Variations in the Eastern and Western Indian Ocean Modulated by Tropical Pacific SST, Buoy Measurements of Wind–Wave Relations during Hurricane Matthew in 2016, The Impact of Dry Midlevel Air on Hurricane Intensity in Idealized Simulations with No Mean Flow. Therefore, no observations are available for 27, 30, 33, and 36 h before landfall. How did Lili generate a storm surge more than 50% higher than Danny, when both storms made landfall with identical wind speeds? Such methods could potentially unravel complex relationships between variables, such as the influence of tropical cyclone size for generating storm surge over shallow bathymetry or the expected difference in surge heights from two storms with identical size and bathymetry but different prelandfall wind speeds. In some cases, however, data were intentionally removed from one or more of the 3-h prelandfall increments. Miami, FL, 33165 All NOAA. In type 8 events CHO is the first inland observation of the second landfall. These improved correlations between surge heights and prelandfall winds in the newer dataset result in every 3-h interval having better correlations than the correlation between surge and wind speeds at landfall. In addition to Katrina’s large size (Irish et al. interstates, 57% of arterials, almost half of rail miles, 29 airports, Such storms may loop as they approach the coast or may briefly track over peninsulas or other protrusions of land before reemerging over water and making another landfall. This photo-like image of the Texas and Louisiana coast shows the impact of Hurricane Ike’s powerful storm surge on coastal wetlands. All of these potential reasons for the nonlinear relationship between prelandfall winds and surge magnitudes are speculative and should be investigated by scientists in the geophysical research community who specialize in atmospheric and oceanographic physics. Although Lili made landfall as a category 1 hurricane, with maximum sustained winds of 148 km h−1 (80 kt), the storm generated a 3.75-m surge in south Louisiana (Pasch et al. While differences in storm size and bathymetry surely enabled Ike to generate a larger surge than Charley, the importance of these parameters is likely overemphasized when referring to Ike as a category 2 hurricane and Charley as a category 4 hurricane. As this paper correlates tropical cyclone winds and storm surge heights at landfall and at 3-h prelandfall increments, determining the precise time and location of landfall is crucial. In these cases, observations are not included in the database until the system forms into a tropical storm. Because surge levels rise in a dome as air pressure near the eye of the hurricane becomes lower, wind stress is not the only physical parameter forcing storm surge. After this landfall, the storm moved inland and made a second loop around Lafayette, Louisiana, before reemerging into the Gulf of Mexico as a tropical storm and moving to the northeast, making a second Louisiana landfall in Plaquemines Parish (Unisys 2012). A difference in storm size emerges as the best explanation for these storm surge heights once maximum sustained winds are eliminated as a factor, because the bathymetry and coastal geomorphology near these two surge events should have been relatively constant. Hurricane Rita was the most intense tropical cyclone on record in the Gulf of Mexico and the fourth-most intense Atlantic hurricane ever recorded. No eye was clearly visible 18 h before landfall; however, a discernible eye was visible at the time of landfall and a distance of 56.5 km (30.5 n mi) was measured. Hurricane Humberto (Figure 3) provides an example of this phenomenon, as this storm only formed into a tropical storm 24 h before the time of COO. (b) Correlation of surge heights vs actual and exponential wind speeds at 3-h intervals for data from 1960 to 2011.