From The Blog
Kiawah Fares Well in Hurricane Dorian
This kind of note seems like an annual occurrence for me now. Each year since 2015, we’ve had a storm event impact the island in some way – a 1000-yearflood, hurricanes and tropical storms, and even an unprecedented snowstorm. I’m grateful to report that the island as a whole fared well in Hurricane Dorian. While we had a big mess to clean up, island facilities,
infrastructure, and homes were spared significant damage. I’m sure you’re as relieved as I am that the impact was not nearly what was anticipated, but it’s important to consider just how close a call we had. Had the storm path shifted slightly west, or if it passed during one of the high tides earlier that week, we would have had serious problems, including the predicted widespread flooding.
KICA resilience specialist Lucas Hernandez reviewed the updates from the National Hurricane Center for Thursday, Sept. 5 at 12 p.m. and 1 p.m., which is the timeframe in which the eye of the hurricane skirted our coast, bringing high-speed winds but less rainfall than the night before. Lucas’s report included the following:
To understand why this storm provided limited inundation despite the high speed winds that accompanied it, we must understand several factors that exacerbate the overall effects of a tropical storm. Timing (in respect to the tide cycle), wind speed/direction, rainfall, low/high pressure systems, and the speed at which the storm moves over a specific location all combine to create an impactful storm. On Kiawah, we received very little rainfall as the storm sped up during its pass by the area (2.24 in. total). Wind speeds were high, but this seemed to be helpful in relation to flooding. The tides staged higher for Sept. 4 than they did during the storm, and again after the storm’s eye passed Charleston. At about 2 p.m. on Sept. 5, the tide gauge readings fell below the predicted values from NOAA. This is inline with the time at which the eye was moving past Charleston.
As the counterclockwise rotation of the storm approached the Charleston area, east to west winds pushed water land ward raising the tidal height; however, this happened at a significantly low tide for our area, offsetting most of the impact. As the storm passed, the tidal cycle began to rise, but due to the storm’s counterclockwise rotation on the back-end, the winds shifted east to west and pushed the water away from the land. This offset the rising tide. “Because the storm was far enough out to sea, the core of the strongest winds stayed east of the coastline” (Ron Morales, CHS NWS). The result was a lower than expected surge and tide stage, which kept inundation minimal for the area. Morales summarized his report by stating, “We got very lucky with how the tides worked out, but the observed winds and rainfall were close to what was forecasted…As scientists, we are always looking to better understand what happened so we can provide a better service in the future. This situation is a great example of why we have to use probabilistic information with hurricanes to express the uncertainty of the impacts. A slight jog to the west in the track, and/or a slower/faster motion would have resulted in far more serious impacts.”
In addition to my relief over dodging a far worse situation, I’m also grateful for the numerous KICA employees who canceled Labor Day plans to prepare for the storm, and the dozens who were here along with our emergency contractors to immediately begin clean up. As reported to the board at a special meeting on Sept. 17, estimates suggest the clean-up and mitigation costs will be between $500,000 and$600,000. We expect to have additional detail in time for the October board meeting, at which time the funding of this effort will be discussed.
While clean-up efforts are ongoing, other aspect of island life and KICA operations have returned to normal. Our staff is hard at work preparing a draft2020 budget, which will soon be reviewed by the Finance Committee. Clubs and groups are getting back into the swing of things, and as I type this, Kiawah and the Lowcountry are getting its first taste of fall weather. It’s a wonderful time of year, and I look forward to seeing many of you around the island.