Director’s Note: Hurricanes and storm prep
It is WAY too early to know what is going to happen with what is now “Tropical Depression 9”. But things can change quickly, and it’s important to know that a storm that people were blasé about can change into a very scary hurricane – like Charley and Punta Gorda in 2004. As well, very dire scenarios can prove to be a false alarm - like Charley and Tampa in 2004.
In 1992, Hurricane Andrew went from a tropical depression to a category 5 hurricane in a week. In 2018, Hurricane Michael went from a category 3 to a category 5 hurricane in a single day. It is important to note that the category of a hurricane refers to wind speed, not the storm surge. The impacts from 1992’s Andrew and 2004’s Charley were mostly from wind damage, while the damage from 2005’s Katrina was mostly due to storm surge. 2004’s Ivan and 2018’s Michael produced massive damage from both storm surge and wind damage. Hurricanes have been described as “heat engines” that convert the thermal energy of warm moist air into mechanical energy – winds and storm surge. And right now, most of the surface layers of the Gulf of Mexico are in the mid to upper 80s – which are ideal temperatures for rapid intensification. Wherever this storm goes, it has plenty of “fuel” to get quite strong quite quickly.
In terms of storm surge, the worst place to be is on the northeast quadrant of the system, while the worst winds are in the eyewall, followed by the northeast quadrant. The force of wind is a function of the square of the wind speed. Which means, a 150-mph storm (category 5) creates roughly four times (not just twice) the destructive wind power as would happen from a 75-mph category 1 hurricane. Also, the winds in hurricanes flow in a counterclockwise rotation (actually NOT due to the Coriolis effect). So if a hurricane has 120 mph winds and is moving south to north (a typical pattern for us here) at 20 mph, then the combined impact would be that of 140 mph on the east side of the storm, vs. 100 mph on the west side, because the effective wind speed is a function of the hurricane’s generated wind and its forward velocity. Now, keep in mind that force is a function of the square of the wind speed, and you can see that being on the east vs. west side of the above-described storm would expose you to twice the damaging wind force from the same storm. Which means, a hurricane with an eye just off to our west would be much worse for us than a hurricane with an eye just to our east.
Before we get to some basics on hurricane prep, our primary focus at the SBEP is to manage the health of Sarasota Bay. So how would Sarasota Bay respond to a major hurricane? Well, it depends on its antecedent health – as discussed in this paper. Bays and parts of bays that are stressed from pollution will have a much harder time recovering from a hurricane than bays or parts of bays that are healthier, as was seen after 2017’s Irma. That is another reason why nutrient management is important – cleaner water allows estuaries to be for more resilient not only to climate change, but to impacts from tropical events. Also, since it is being discussed locally, it’s worth noting that the original “Midnight Pass” was likely formed by the 1921 hurricane that hit our area, just like “Irma Pass” up by Ft. Desoto was formed in 2017. If we get a hit by a major hurricane, there are a number of low-lying areas on our barrier islands where new passes could form, even if only temporarily.
For those new to Florida, keep in mind that the rule of thumb is to be ready for not having power for at least 3 days. Fill up your bathtubs, not only for drinking water, but for water you can pour into your toilet tank so that you can still flush your toilet when power goes out. Because when power goes out, so does the ability to pump water – at least temporarily. Stock up on food you don’t have to warm up to eat, unless you have a camp stove. Make sure you have a hand-cranked can opener. Do NOT run a generator in your garage – that’s a great way to kill off your family. And, very important, stock up on bug spray and baby wipes. I have run hurricane relief centers (after Charley) and when windows on houses get blown out, or screens damaged and there’s no AC, you’ll be sleeping in a hot buggy place for a while. It’s really nice to have bug spray, and it’s also really nice to use baby wipes to wipe off that bug spray and take a “shower”. Just don’t flush those things, as the utilities will have trouble enough afterwards.
This might all come to nothing for us, but according to the National Hurricane Center, we are likely to begin to experience at least tropical storm winds starting Tuesday morning - TROPICAL DEPRESSION NINE (noaa.gov). Prepare, but don’t obsess, and look out for your friends and neighbors who might be older or less able to prepare than you are. Hurricanes can do terrifying damage, but the aftermath can draw communities together in ways that are actually pretty cool to experience as well. For 30 years now, I go out after hurricanes with my AWD vehicle packed with tarps and a chainsaw and drive to places like Florida City in 1992, Wauchula in 2004, Immokalee in 2017, and the Panhandle in 2018. I just drive around in battered neighborhoods and ask people if they need help with clearing trees off their cars or roofs, etc. It’s a way to feel useful, by helping out some of the folks who are left to fend for themselves after a storm. I would recommend it to anyone – it’s a nice feeling at the end of the day, even if you only helped one person.