The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: What If Ian Were to Slam into Tampa Bay?
Dear Diary. Let’s get one thing straight right off the bat. I’m not at this point forecasting that Hurricane Ian will go directly into Tampa Bay, although guidance as of Monday morning is beginning to consolidate towards that outcome. Even if the system weakened to a CAT1 and remained well offshore, the Tampa area would see some bad storm surge effects.
Over a week ago models hinted at a dire outcome:
And this morning, after many operational GFS runs pulled Ian well west of Tampa, we are back to Ian tracking into Tampa:
The Tampa/St. Petersburg area has been very fortunate over the past 100 years without seeing a direct hit from a major hurricane. The last one hit in October 1921. Builders, developers and residents have become quite complacent during this time with many structures now susceptible for major data, if not getting entirely washed away due to winds, storm surge and waves. The good news, of course, is that unlike in 1921 there will be ample warning for residents to evacuate.
What has me worried here, though, is that Gulf waters are warmer than they were in October 1921 due to climate change, which will be a big factor now and for years to come.
So, what exactly could happen if a major hurricane were to move into Tampa? Here is a BayNews article from last year giving us big clues:
Surge damage in Channelside from the 1921 hurricane. (Hillsborough County Public Library)
What would happen if the Hurricane of 1921 hit Tampa today?
By Meteorologist Nick Merianos Florida
PUBLISHED 3:15 PM ET Jun. 15, 2021
This year marks 100 years since Tampa Bay took a direct hit from a major hurricane. The storm is known as the Tampa Bay Hurricane of 1921 and it devastated much of Tampa Bay. Our population has grown by nearly three million people since we were last hit, making our area exceptionally vulnerable.
What You Need To Know
1) The Tampa Bay Hurricane of 1921 made landfall over Tarpon Springs
2) A 10.5-foot storm surge inundated downtown Tampa
3) Tampa Bay washed over parts of Pinellas County, splitting it in half
4) Our population has grown by nearly three million people over the last century
The Hurricane of 1921 made landfall as a Category 3 over Tarpon Springs. The storm came in from the southwest and this trajectory is the worst-case scenario for Tampa Bay, especially when it comes to storm surge. At the height of the storm, parts of Pinellas County were split into two islands as the surge from Tampa Bay overflowed back into the Gulf.
“Not only are you cutting off part of Pinellas County from the other part,” says Brian McClure, Bay News 9 Meteorologist, “but you’re cutting off what little transportation such as your roads that you had in and out, now they’re cut off.”
Railroad damage on Bayshore caused by the 1921 Hurricane. (Hillsborough County Public Library)
There’s no question that a storm like this will happen again. The return rate is about every 100 to 150 years. Statistically speaking, we are in that window, and chances are we will eventually see one in or near Tampa Bay. It may not happen for another 10 years or another 50 years, but the day will come.
The surge from the 1921 Tampa Bay Hurricane inundated downtown Tampa with 10.5 feet of water.
Damage at Garrison Channel in Tampa from storm surge caused by the 1921 Tampa Bay Hurricane. (Hillsborough County Public Library)
The surge was so bad in Tampa Bay because of the hurricane’s trajectory. The storm came in from the southwest and made landfall just north of Tampa Bay. A hurricane moving on this path will force a lot of water into Tampa Bay, resulting in a serious storm surge.
“Irma was totally different,” says Brian McClure. “It sucked water away from the bay.”
Hurricane Irma made landfall south of Tampa Bay and that meant we had strong offshore winds pushing water away from the bay, rather than strong onshore winds like the 1921 hurricane.
“Then you have what we considered a small Tropical Storm Eta, it was a hurricane briefly but it really was a tropical storm when it came through. There was three feet of water right across the roads on the barrier islands,” adds McClure.
Homes near John’s Pass flooded, including one home that took on 2.5 feet of water. The surge from Tropical Storm Eta flooded parts of Bayshore in Tampa and 33 people were rescued in Pinellas County from high water.
What would happen if another hurricane like the 1921 Tampa Bay Hurricane hit today?
First, we know was a 3.5-foot surge looks like in Tampa after recently experiencing Tropical Storm Eta, where it flooded Bayshore Drive. The surge from the 1921 hurricane was reported to be seven feet higher. That means the surge in downtown Tampa reached 10.5 feet. This would place the water level there up to the second-story balcony on many coastal buildings.
Many of our airports would flood, including parts of Tampa International, Clearwater St. Pete International, Peter O’Knight and Albert Whitted Airport.
Damage on Bayshore after the 1921 hurricane. (Hillsborough County Public Library)
Other important pieces of infrastructure would be submerged or affected by the surge, such as the wastewater treatment facility and the gas storage tanks.
Transportation would come to a halt across coastal areas, especially in Pinellas County, because parts of it could become an island.
Tampa Bay would not only flood the cities right on the coast, but the water would flow and take the path of least resistance. A bayou cuts across Pinellas County starting near Feather Sound and flows toward the Gulf. A stretch of Pinellas County would be submerged, essentially splitting the county into two islands.
Topography map of Pinellas County. (United States Geological Survey)
“The water gets shoved up into the Bay,” says McClure. “Not only does it start to then spill over onto land and into your cities, but then it tries to come back out. If you’re shoving the water into the mouth of the bay, it can only go where the course of least resistance is, the lowest-lying areas.”
Fortunately, our cities are not below sea level. Cities such as New Orleans and Houston have several communities that are below sea level.
“If it comes at us, we’re going to have a problem day of and during recovery,” says McClure. “At least the water isn’t going to sit in downtown. It will go funneling back out.”
Aftermath on Palmetto Beach after the 1921 Tampa Bay Hurricane. (Hillsborough County Public Library)
One of the biggest problems we would see in Tampa Bay with a storm like the 1921 hurricane would be in the days immediately following the hurricane: finding basics such as food and water or establishing transportation to send out supplies to areas hard hit. The recovery could be a shell shock to many people.
Storm surge damage in Channelside from the 1921 hurricane. (Hillsborough County Public Library)
The population around Tampa Bay has grown by nearly three million people since the 1921 hurricane. The population boom over the last century has made Tampa Bay especially vulnerable.
“Now you have so many people right here in the Bay Area. Yeah, you can leave, but eventually, everybody wants to come back,” adds McClure. “That’s the part that worries me, the infrastructure build-out then the repair afterward. How long does it take?”
McClure notes that some people never returned back to New Orleans after Hurricane Katrina.
Flooding along Bayshore from the 1921 hurricane. (Hillsborough County Public Library)
One of the things about studying past storms is knowing what eventually happened. We can use that information to predict what may happen again in a similar situation when another storm like it strikes our area again. The best thing to do is be prepared ahead of any hurricane season. All it takes is one hurricane to hit your community to make any season a bad one.
It’s not difficult to survive a hurricane, but proper planning ahead of any storm makes the days following the hurricane less challenging.
Here is more news and notes on Hurricane Ian:
Here are some “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks:
Here is more climate and weather news from Monday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)
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Guy Walton “The Climate Guy”