The odds of a hurricane spoiling the Republican National Convention in Tampa

By: Dr. Jeff Masters , 4:48 PM GMT on August 14, 2012

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On September 25, 1848, the Great Gale of 1848, the most violent hurricane in Tampa's history, roared ashore as a Category 3 or 4 hurricane with 115 - 135 mph winds. Major R. D. S. Wade weathered the storm in Fort Brooke, in what is now downtown Tampa. Here is what he wrote this to his commanding officer in Washington D.C.: "The waters rose to an unprecedented height, and the waves swept away the wharves and all the buildings that were near the Bay or river." A 15-foot storm surge was observed at Fort Brooke, and the peninsula where St. Petersburg lies in Pinellas County was inundated "at the waist" and "the bays met," making St. Petersburg an island. After the hurricane, "Tampa was a scene of devastation. Magnificent old oaks were toppled by the hurricane's winds. At Fort Brooke the barracks, horse shed, and other structures were gone. The pine forest north of the garrison was filled with wreckage and debris. The hurricane's powerful surge had shifted sand all along the coast and reshaped many of the keys near Tampa Bay. Navigation routes were filled in and closed, making charts of the area produced before 1848 almost useless after the hurricane. In terms of intensity and destruction, the 1848 storm remains perhaps the greatest in Tampa's history" (Barnes, 1999.)


Figure 1. Pencil sketch of the Captains' Quarters, drawn by one of the officers stationed at Fort Brooke in 1845. Fort Brooke was one of the largest military establishments in the United States at the time. Image Credit: The Tampa Bay History Center.

Fort Brooke today
Fort Brooke is the current site of the Tampa Bay Convention Center, which hosts the Republican National Convention on August 27 - 30 this year. The convention center is in Evacuation Zone A, which is evacuated for Category 1 hurricanes. The Tampa Bay Times Forum and two major convention hotels--the Tampa Marriott Waterside and the Embassy Suites--are in Evacuation Zone B, which is evacuated for Category 2 hurricanes. In a worst-case Category 4 hurricane, the Convention Center could be immersed in 20 feet of water. Clearly, even a Category 1 hurricane would be enough to spoil the convention. So, what are the odds of a mass evacuation order being issued for Tampa Bay during the convention?


Figure 2. Predicted height above ground of the water from a worst-case Category 4 hurricane in the Tampa Bay region, as computed using NOAA's SLOSH storm surge model. The Tampa Bay convention center would go under 20 feet of water, and St. Petersburg would become an island, as occurred during the 1848 hurricane.


Figure 3. Perhaps the most spectacular hurricane image ever captured: view of Hurricane Elena on September 1, 1985, as seen from the Space Shuttle Discovery. At the time, Elena was a Category 3 hurricane with 125 mph winds, located just 80 miles offshore from Tampa Bay, Florida. The hurricane prompted the largest mass evacuation in Tampa Bay history.

Two mass evacuations in Tampa in the past 25 years
Two hurricanes have prompted mass evacuations of more than 300,000 people from the Tampa Bay area over the past 25 years. The first was Hurricane Elena of 1985, a Category 3 hurricane that stalled 80 miles offshore for two days on Labor Day weekend, bringing a 6 - 7 foot storm surge, wind gusts of 80 mph, and torrential rains. On August 13, 2004, another mass evacuation was ordered for Hurricane Charley. Thanks to a late track shift, Charley missed Tampa Bay, and instead hit well to the south in Port Charlotte as a Category 4 storm with 150 mph winds. More limited evacuations of low-lying areas and mobile homes in the 4-county Tampa Bay region were ordered for three other hurricanes in the past fifteen years--Hurricane Georges of 1998, Hurricane Frances of 2004, and Hurricane Jeanne of 2004. Other historical storms which would likely trigger mass evacuations were they occur today include:

The 1921 hurricane. One of only two major hurricanes to hit Tampa, this Category 3 storm brought a storm tide of 10.5 feet.

Hurricane Easy of 1950. The hurricane parked itself over the west coast of Florida, drenching residents with record-breaking rains, and brought a 6.5 ft storm surge to Tampa Bay.


Figure 4. Damage to Bayshore Boulevard after the 1921 Tampa Bay hurricane. The road leads to the Tampa Bay Convention Center from the south.


Figure 5. Track of the Tampa Bay Hurricane of 1921, one of only two major hurricanes ever to hit the city. This Category 3 storm with 115 mph winds brought a storm tide of 10.5 feet to Tampa Bay.


Figure 6. A near miss: just a slight deviation in the path of Hurricane Charley of 2004 would have brought the Category 4 hurricane into Tampa Bay.

Tampa Bay's vulnerability to hurricanes
Tampa Bay doesn't get hit very often by hurricanes. The last time it suffered a direct hit by any hurricane was 1946, when a Category 1 storm came up through the bay. The Tampa Bay Hurricane of October 25, 1921 was a the last major hurricane to make landfall in the Tampa Bay Region. At that time, there were 160,000 residents in the 4-county region, most of whom lived in communities on high ground. Today there are 2.75 million residents in the region, most of whom live along the coast and low-lying areas or in manufactured housing. About 1/3 of the 4-county Tampa Bay region lies within a flood plain. Over 800,000 people live in evacuation zones for a Category 1 hurricane, and 2 million people live in evacuation zones for a Category 5 hurricane, according to the 2010 Statewide Regional Evacuation Study for the Tampa Bay Region. Given that only 46% of the people in the evacuation zones for a Category 1 hurricane evacuated when Category 4 Hurricane Charley threatened the region, the potential for hundreds or thousands of people to die when the next major hurricane hits the region is high. In the long run, I expect a multi-billion dollar sea wall will be built to protect Tampa Bay from storm surges, since sea level rise will make storm surge damages increasingly problematic. A 2007 study by Tufts University titled, Florida and Climate Change, found that a 2.25 foot increase in sea level--which many sea level rise scientists expect will happen by the end of the century--would put 152,000 people in Pinellas County (where St. Petersburg is located) at risk of inundation.

The hurricane forecast for the Republican National Convention
Given that there have been two mass evacuations of Tampa during the past 25 years during the peak three-month period of hurricane season--August, September, and October--history suggests that the odds of a mass evacuation order being given during the 4-day period that the Republican National Convention is in town are probably around 0.2%. Any tropical waves which might develop into hurricanes that could hit Tampa during the convention would have to come off the coast of Africa next week. Looking at the latest 16-day forecast from the GFS, all of the tropical waves coming off of Africa next week are predicted to exit too far north to make the long crossing of the Atlantic and threaten the Gulf Coast. While something could develop in the Gulf of Mexico from the remains of an old cold front, it is rare for such storms to grow strong enough to deserve mass evacuations. So far, early signs point to a hurricane-free Republican National Convention at the end of August.

References
Barnes, J., 1999, Florida’s Hurricane History. The University of North Carolina Press.

Weisberg, R.H, and L. Zheng, 2006, "Hurricane storm surge simulations for Tampa Bay", Estuaries and Coasts Vol 29, No. 6A, pp 899-913.

History of Pasco County: The 1921 Hurricane

The 2010 Statewide Regional Evacuation Study for the Tampa Bay Region

The Tampa Bay Catastrophic Plan for a Category 5 $250 billion hurricane

Jeff Masters

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Been saying for a couple days now that the Central Gulf is priming for some formation. Still think that energy has been getting backed into the Central Gulf area. Energy there hasn't been pushed in any direction and something is slowly trying to manifest. Thought maybe we'd see some convection in the area today. While there was none today, over the next 48/72, I think that many well change.
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Quoting pottery:

I wonder what it means ?
Polar shift? Just thinking out loud.
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Any tropical waves which might develop into hurricanes that could hit Tampa during the convention would have to come off the coast of Africa next week... JM



omg...look what's headed to the Republican National Convention...

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The ITCZ coverup.......

Link



It's dem WXmod HAAAARP folks hiding somthin..... ; )
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Quoting CosmicEvents:
You know any Mayans?

Orca went to Cancun.
Does that count?

:):))
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Over Africa, the ITCZ is running between 18n-20n, which is 'normal'.
Strange to see the strong dip toward the equator across the Atl.
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MJO has really gone capput....much weaker than before forecast
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Quoting pottery:

I wonder what it means ?
You know any Mayans?
Member Since: August 3, 2005 Posts: 10 Comments: 5562
Quoting CosmicEvents:
Strange indeed. It seemed to be gone then, as it appears now. I don't recall it this far south at any time.

I wonder what it means ?
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Still no 15August12amGMT ATCF report, BUT TropicalWaveSeven had a mid-level spin
centered at ~15.0n83.5w for 14August6pmGMT, and at ~14.1n85.2w for 15August12amGMT
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Quoting pottery:

Yeah, I saw your earlier post.
Kind of strange for it to be so far south Aug 15Th, no ?
Strange indeed. It seemed to be gone then, as it appears now. I don't recall it this far south at any time.
Member Since: August 3, 2005 Posts: 10 Comments: 5562
Quoting CosmicEvents:
I mentioned something about that the other day. I noted that the NHC had the ICTZ down near the equator at one point, at 3 degrees north. Today I see that it's even closer to the equator. As per the NHC 8PMestTWO: THE INTERTROPICAL CONVERGENCE ZONE
AXIS EXTENDS FROM 06N40W TO 02N51W.

Yeah, I saw your earlier post.
Kind of strange for it to be so far south Aug 15Th, no ?
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Quoting KEEPEROFTHEGATE:
latest hemispheric ir anim image 10 mins old



looks like Ireland is getting whacked. That's one impressive easterly wave/MCS over west Africa.
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This blog is dead!!!! Definitely need a storm to track!
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Quoting pottery:
The ITCZ over the Atlantic seems to have gone to sleep...
I mentioned something about that the other day. I noted that the NHC had the ICTZ down near the equator at one point, at 3 degrees north. Today I see that it's even closer to the equator. As per the NHC 8PMestTWO: THE INTERTROPICAL CONVERGENCE ZONE
AXIS EXTENDS FROM 06N40W TO 02N51W.
.
.
Can we go into the SH at some point?
Member Since: August 3, 2005 Posts: 10 Comments: 5562
Quoting KEEPEROFTHEGATE:


strange eh
been that way since all the rain fell
in trinny
shut down right afer that

True!

Sorry 'bout that!

:):))
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Quoting bayoubug:
By looking at the water vapor loop of the gom..It looks to me that a ull might be developing in the central gulf..Take a look could be wrong..


I saw that earlier. We'll watch it.
Member Since: August 4, 2007 Posts: 0 Comments: 3231
Quoting Jebekarue:
I have noticed in the last few days here in Pensacola that the leaves are already starting to change color!!! It's wayyy to early!!
Trailriding Sunday we found quite a few places where leaves were already changing over red. As you said, "way too early"!
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Quoting pottery:
The ITCZ over the Atlantic seems to have gone to sleep...


for now looking at climo wait till Sept starts

and I have a feeling that we will have an explosion with activity when Sept comes
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Seriously. OK, I mean, as usual... semi-seriously. :)
Member Since: October 19, 2005 Posts: 14 Comments: 188
Quoting mitthbevnuruodo:


I'm sure the green one goes right over my house!
A days or so ago, the GFS had a aoi in the central gulf crossing central FL. A Debby sort of move. Then it developed the same thing over the w gulf, into MX. Now reforms and heads it northeastward, with a little stall. I would not be surprised to see it back toward FL getting dragged along with that front.
Now, I know I used a lot technical terms in my report, but yes, I believe it could head more easterly should something develop. BTW, is that ex 93L I'm talking about?

Edit: and if it gets legs, it could be in time for the NHC (although, would hate to see that happen)
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Quoting pottery:
The ITCZ over the Atlantic seems to have gone to sleep...


strange eh
been that way since all the rain fell
in trinny
shut down right afer that
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The ITCZ over the Atlantic seems to have gone to sleep...
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latest hemispheric ir anim image 10 mins old

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I wish I could enter chat, stupid apple products that won't let me enter.
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Quoting LargoFl:
..might be from all that rain these last few weeks, sun must have been hidden quite alot with all the clouds huh


It's gotta be from all of the rain we have had lately. I saw yesterday that we have already had almost 6" of rain this month. That's not including the rain that we got today and this evening. Temps have still been in the low 90's everyday and the lows at night in the upper 70's. No way it's a sign that Fall will be here soon.
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basin shot
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858. MTWX
Quoting aislinnpaps:
I lived about an hour from Wurzburg. I also love Trier and Burg Eltz


My mom was born in Mainbernheim. Most of her side of the family still live there or in Wurzburg.

The last time I visited, I actually got to see the house her grandfather built by hand out of stones he collected from the nearby farm fields. It was amazing!!
Member Since: July 20, 2009 Posts: 23 Comments: 1393
Quoting washingtonian115:
I give it a 85% chance of it ever developing.

I would give a % chance but I haven't been watching the invest. It does look good and I saw a good chance of development, that's all I can say.
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Quoting SubtropicalHi:


The sound of that water! (Usually when we see these videos on TV, there isn't any sound)

It sounds like a big waterfall.....
But then there are bumps and thumps and bangs too, when boulders and logs come down.

I can often hear the rain coming when it is heavy, falling on the forest a mile to my easy.
It is noisy on big trees.
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wow look at that area of EX-TD7
light blues

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Quoting Tropicsweatherpr:


Al that rain there was caused by the southern end of Ex TD7?

Yes, we had rain all weekend Islandwide.
I got 2.5", and I know that others south of me got 4" Sat/Sun.
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Nice structure/banding on 93L.
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Quoting MTWX:


Wurzburg has always been my favorite!! Wish I could go there again.


I lived about an hour from Wurzburg. I also love Trier and Burg Eltz.
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851. MTWX
Quoting Grothar:


Very nice place. Too bad so little remains of the old city. Much of it was destroyed. Beautiful place, though. (They talk funny there)


It is sad that much of the old city was destroyed during WWII.

As far as them talking funny... There is quite a mixture of dialects there!! LOL!
Member Since: July 20, 2009 Posts: 23 Comments: 1393
Quoting WxGeekVA:


Nope, everyone is real. LOL!
That rather bothers me. The use of foul language is just unnecessary. You are not even responding to anything. Just cussing up a storm lol.
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Quoting Patrap:


Those outflow Boundaries have caused a few Storms..your way.



It got bad!
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Quoting mitthbevnuruodo:


But I live in the middle of nowhere and have no neighbors...if I did, I would totally pick them! LOL Would only be the remnants of something by the time it got here anyway! And anyway, don't get that many even remnants making it here! :P


Aw, I wasn't picking on you. I hadn't seen your comment until after I posted mine. It actually was referring to someone else. :)
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Quoting MAweatherboy1:
93L trying to get a little convection going near its center:


Looking more like a TC, needs convection but looking way better.
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Quoting pottery:

Yeah, I was up there yesterday.
Took the pavement off the roads.
Shows what the power of the water is like, running down those hills.
Tens of millions $$$$ damages.


The sound of that water! (Usually when we see these videos on TV, there isn't any sound)
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Quoting pottery:

2 men were killed.
One when his house was swept into a river, another when a hillside fell onto his house.
Very tragic.

The closest weather stations recorded 3" of rainfall.
Both those stations are 2 miles away from the worst areas.
A friend who lives in the La Horquette area said he has never seen rain fall as hard as that. So without any stations in the areas most affected we don't know what the rainfall was.

Looks like a major cloudburst over the mountain ridges at the head of the valleys.


All that rain there was caused by the southern end of Ex TD7 as it moved by to your north?
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Quoting wxchaser97:
Checking in, with 93L at 50%, what are your thoughts on this becoming Gordon?
I give it a 85% chance of it ever developing.
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Quoting WxGeekVA:


Nope, everyone is real. LOL!

As in Reality shows ???
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.
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By looking at the water vapor loop of the gom..It looks to me that a ull might be developing in the central gulf..Take a look could be wrong..
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Quoting hurricanehunter27:
I have to ask is everyone in the Weather Chat a fake?

What? I know there is an imposter problem but still. I can't wait to get home and on a regular computer.
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93L trying to get a little convection going near its center:

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Quoting hurricanehunter27:
I have to ask is everyone in the Weather Chat a fake? (Cause if not then wow)


Nope, everyone is real. LOL!
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Quoting BahaHurican:
Trying to remember, but wouldn't an AEW that was huge over WAfrica have more difficulty in adapting to the water? I'm not thinking about actual lows in this context.

I wasn't aware of that.
Seems to me, if it's strong it's strong.
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I have to ask is everyone in the Weather Chat a fake? (Cause if not then wow)
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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