Quick apology: I intended to write this soon after returning home, but “other stuff” kept me busy and this got wedged and shoved into the background clutter of my cluttered brain. Later when I was writing an article about becoming a pilot, I had to turn off the computers, unplug them from the wall, and consider where I was gonna take cover as I spied a pair of funnel clouds menacing me from the north. As I watched them thankfully retract into the clouds and pass me by, this percolated back to the top of my mind.
Mother Nature Always Wins
OK, now to the gist of the matter: When you are being menaced by old Mother Nature, if you have the option –
GET THE HELL OUT!!!!
Read It, Know It, Live It! And continue living!
I’ve flown damage assessment for tornadoes, hurricanes, fires, and floods. Flying over the damage left by Ian is something I won’t forget anytime soon. The official tally is bad enough:
146 deaths in Florida, 157 total.
Lee County, Florida, alone experienced catastrophic impacts from Ian, particularly due to storm surge. Combined with high winds this resulted in some degree of damage to 52,514 buildings and homes, which included minor damage to 16,314 structures, major damage to 14,245 structures, and the total destruction of 5,369 others.
Ponce Inlet, Florida, recorded 31.52 inches of rain. Storm surge was up to 15 feet. A bridge and causeway were both left impassable. 2.4 million Florida residents were left without power. Rivers overflowed in multiple areas along the storm’s path.
But the facts and numbers don’t really tell the whole story.
Houses, businesses – everything people once owned – nothing but a concrete slab left.
Debris, debris, debris piled high – the remains of people’s home and all their possessions – miles and miles of it.
Boats, from dinghies to multimillion dollar yachts, tossed inland in what was once someone’s back yard.
Flood waters everywhere, still receding, rescuers and stranded people wading out, or waiting for a boat, or waiting for a helicopter to get them to safety – or waiting for news of their missing family members.
Alligators, snakes – stranded, everywhere looking for high ground and safety. I’ve never seen so many in one place.
Mobile homes – some disintegrated into matchsticks – the metal ones looking like huge twisted up beer cans.
Hurricanes vs. Tornadoes?!
As I looked down at the destruction while previous similar images floated up in my mind, the word I thought of wasn’t “hurricane” – it was “tornado.”
I think that’s the core problem that explains what I was seeing. For lack of a better phrase, the dangers of hurricanes aren’t “marketed” properly. Consider these two scenarios that represent exactly the same physical dangers:
Reporter: “Sir, you are in the direct path of a very large, high end category 4 hurricane that will arrive in 24 hours. Are you going to evacuate?”
Resident: “Nah. Me and the family have ridden out hurricanes before. No big deal, we’ll be just fine.”
Reporter: “Sir, in 24 hours, an F4 tornado is going to come dance on your head. It’s not a small tornado that will pass over in a few seconds or minutes but will be pounding you and your home for over 3 hours. It’s going to dump as much as three feet of rain on you and push up fifteen feet of ocean water right where you are standing. Nothing will be left but the concrete slab of your home. Are you going to evacuate?”
Resident: Yelling over his shoulder, “Get them kids in the car and let’s get the hell out of here NOW!”
But are they really the same? Let’s take a look at Ian not as a hurricane, but as a tornado.
The original F scale for tornadoes has been replaced with the Enhanced Fujita scale – the EF scale:
|Enhanced Fujita Tornado Scale
Your home or anything else doesn’t care whether the wind is from a hurricane or a tornado – the speed along is all that matters.
Using data from NOAA, the National Oceanic and Atmospheric Administration, I recast Ian in tornado terms.
Ian made landfall at Cayo Costa, Florida, with sustained winds of 150 mph with higher gusts. I tried to find an exact definition of “higher gusts” but couldn’t nail down anything other than “greater than 10 knots, 11.5 miles per hour.” So I used hurricane Carla which struck the Texas coast on September 11, 1961, as a guide because it was also a very large high end category 4 hurricane.
It was also the only hurricane I have “voluntarily” ridden out. (I rode out two hurricanes and a typhoon involuntarily on big gray ships with a bunch of the other miserable folks in blue uniforms. Another story for another time.) I was a kid and didn’t have much choice as my parents were staying. It turned out to not be a bad choice for several reasons. We were 30 miles from the coast on built up land that wouldn’t flood no matter how much rain fell. We had moved into the “big new house” which my dad had confidence in as he had built it. There were no large trees nearby and any potential flying debris had been secured. My grandparents and the rest of the local extended family all moved in with us for the duration. The highest wind speed we recorded was 110 miles per hour and other than a couple of lost shingles, we had no other damage.
The coastal area was another story, and looking back, it was a foretaste of Ian. The official report was that Carla had sustained winds of 145 with gusts of 175 for a difference of 30 miles per hour. The sustained winds at Matagorda, Texas, where we later built a beach house, had sustained winds of 115 with gusts to 160, a difference of 45 miles per hour. Victoria, Texas, had sustained winds of 110 with gusts to 150 for a difference of 40 miles per hour. No one knows exactly how high the wind got at Port O’Conner where Carla made landfall. The last reading was 175 miles per hour which was right before the anemometer, the building it was on, and the rest of the town “left the planet faster than Elvis.”
I took a conservative approach and only used 20 miles per hour for the gust differential for Ian. I suspect it was much higher based on the Carla observations. Thus, in tornado terms, it’s wind speed maxed out at 170 miles per hour which put it in the EF4 range.
I created the map below showing the various widths of the Enhanced Fujita tornadic winds along the coast. I used 170 mph as the speed at the eyewall and then using NOAA and the National Weather Services’ doppler radar measurements for the extent of hurricane force sustained winds and tropical storm force sustained winds to derive the wind speed at the coast using an exponential curve fit. (I’ll stop with the math before any eyes start to glaze over.)
The wandering red line shows the extent of the sustained hurricane force wind field at landfall. The similar yellow line shows the sustained tropical force wind field. As the storm move across Florida, all of state except for the panhandle was subjected to at least tropical force winds. The white lines and arrows show the extent of the various tornadic wind speeds along the coast.
At landfall, the sustained tropical force wind field with higher gusts was about 337 miles wide. The sustained hurricane force wind field with higher gusts was about 97 miles wide.
The really eye popping thing, however, is the gust wind speeds expressed in Enhanced Fujita tornadic wind speed.
The EF4 winds, 166 to 200 miles per hour hit about a 33 mile wide stretch of the coast! I can concur on the “devastating damage” assessment.
The EF3 winds, 136 to 165 miles per hour covered about a 55 mile wide stretch of the coast.
The EF2 winds, 111 to 135 miles per hour covered about a 72 mile wide stretch of the coast.
The EF1 winds, 86 to 110 miles per hour covered about a 86 mile wide stretch of the coast.
The EF0 winds, 65 to 85 miles per hour covered about a whopping 185 mile wide piece of the coast.
Most tornadoes are EF3 or less, most typically about 110 miles per hour wind speed, with a width of 250 feet or less, and stay on the ground for a mile or two. The monster EF4’s and EF5’s are thankfully extremely rare and can reach speeds over 300 miles per hour, be several miles wide, and stay on the ground for hundreds of miles.
Comparing them to Ian’s EF4 33 mile width and coupled with Ian’s slow speed of about 9 knots, 10 miles per hour, means that Ian impacted a huge area much larger than any typical tornado and did it for a longer period of time. And with the 15 foot storm surge that is not a factor for tornadoes
So – if you live along a coast subject to hurricanes, when you here “hurricane” think “tornado” and –
GET THE HELL OUT!!!!
Save your life and that of your family!