Quiet in the Atlantic; lessons learned from Hurricane Hugo's storm surge

By: Dr. Jeff Masters , 12:35 PM GMT on September 21, 2009

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The tropical disturbance (98L), midway between Africa and the Lesser Antilles Islands, has grown weak and disorganized. No development of this disturbance is likely to occur.

The remains of Hurricane Fred are still kicking up heavy thunderstorms about 400 miles east of the Georgia-Florida border. Fred-ex's circulation has become ill-defined, as seen in last night's QuikSCAT pass. Fred-ex is under about 20 knots of wind shear, and this shear is expected to remain about the same over the next two days. Fred-ex will be moving ashore Tuesday night or Wednesday along a stretch of coast from Florida to North Carolina, bringing heavy rains to some areas. There is too much wind shear and dry air, and not enough time, for Fred-ex to develop into a tropical depression. I don't expect it to cause any flooding problems when it moves ashore.


Figure 1. Morning visible satellite image of Fred-ex, 400 miles east of Florida.

Twenty years ago today
On September 21, 1989, Hurricane Hugo began the day as a minimum-strength Category 3 hurricane with 115 mph winds. But as a strong trough of low pressure turned the hurricane to the north and accelerated Hugo to a forward speed of 25 mph, the storm took advantage of low wind shear and warm ocean waters to begin a period of rapid intensification. As darkness fell on the 21st, Hugo had grown to huge Category 4 hurricane with 135 mph winds. Its target: the South Carolina coast near Charleston, at Sullivan's Island. At 11:57 pm on the 21st, Hugo made landfall on Sullivan's Island. It was the strongest hurricane on record to hit South Carolina, and the second strongest hurricane (since reliable records began in 1851) to hit the U.S. East Coast north of Florida. Only Hurricane Hazel of 1954 (Category 4, 140 mph winds) was stronger.


Figure 2. AVHRR visible satellite image of Hurricane Hugo taken on September 21, 1989. Hugo had intensified to a formidable Category 4 hurricane with 135 mph winds.

On Isle of Palms, a barrier island adjacent to Sullivan's Island, the mayor and several police officers were sheltering in a 2-story building which lay at an elevation of ten feet. As related in a story published in the St. Petersburg Times, they heard the following bulletin on the radio at 10:30pm the night Hugo made landfall:

"The National Weather Service has issued a storm surge update. It appears that the storm surge will be greater than anticipated. It is now expected to reach a height of 17 to 21 feet."

"Mom didn't raise an idiot," said the one cop with the most sense, and he convinced the others to get off the island. They left the island by driving at 5 mph through horizontal sheets of rain and hurricane-force wind gusts over the Ben Sawyer Bridge, which connected Sullivan's Island to the mainland. As they crossed onto the bridge, they passed over a large bump--the bridge and road bed were at different levels. Not good. While crossing the bridge, they could feel it swaying and straining, and heard the sound of metal, twisting and grinding and breaking. They made it, but only barely--minutes later, the hurricane tore the center span of the bridge from its connection on both ends, leaving it a twisted ruin in the bay.


Figure 3. The Ben Sawyer Bridge connecting Sullivan's Island to Charleston, South Carolina, after Hurricane Hugo. Image credit: NOAA Photo Library.

Hugo's storm surge
In McClellanville, on the coast thirty miles northeast of Charleston, between 500 - 1100 people took refuge at the designated shelter for the region, Lincoln High School. Lincoln High is a one-story school, mostly constructed of cinder block, located on the east side of Highway 17, and was believed to be at an altitude of twenty feet. McClellanville is about 4 - 5 miles inland from the open ocean, but lies on the Intracoastal Waterway, so is vulnerable to high storm surges. Near midnight on the 21st, a storm surge of twenty feet poured into Bulls Bay just south of McClellanville, and funneled into the narrow Intracoastal Waterway. Water started pouring into the high school and rose fairly rapidly. Within minutes, people were wading around up to their waists, the water still rising. In the school cafeteria, many refugees gathered on a stage at one end, putting children up on tables. The elevated stage kept them above water; others floated in the water. Another group was in the band room, which had a much lower ceiling than the cafeteria. They had to stand on desks and push out the ceiling tiles for more breathing room, as the water rose within 1 - 2 feet of the ceiling. Fortunately, Hugo's storm surge peaked at that time, at about 16 - 17 feet (Figure 4), and the people sheltering at Lincoln High were spared.


Figure 4. Estimated storm surge (height above ground) as estimated by NOAA's storm surge model, SLOSH. McClellanville (upper right) received a storm surge estimated at 16 - 17 feet.

According to Dr. Stephen Baig, the retired head of the NHC storm surge unit, the back-story is this: To build Lincoln High School, which lies at an altitude of ten feet, the local school board used the same plans that were drawn up for another school that is west of Highway 17, and that IS at 20 feet elevation. Not only the same plans, the same set of working drawings. Those working drawings showed a surveyed elevation of 20 feet above datum (probably NGVD29). Apparently Lincoln High was constructed either without benefit of elevation survey or the plans were not annotated with its site elevation. When the Red Cross inquired as to its utility as an evacuation site, whoever looked at the plans saw the surveyed elevation at 20 feet. That is what the Red Cross published. That is why the school was a designated shelter. Since that near-tragedy, the Red Cross requires a new elevation survey for every potential storm shelter. I think that at the time this was discovered all the designated shelters also were re-surveyed, just to be sure that no similar Lincoln High problems were waiting to happen.

Only one person died from Hugo's storm surge, a woman who sheltered in her mobile home that got struck by the surge. Her death was one of only ten deaths that have occurred due to storm surge in the U.S. in the 35 years between 1969 - 2005 (after the 100+ storm surge deaths due to Hurricane Camille of 1969, and before the 1000+ storm surge deaths due to Hurricane Katrina). This amazingly low death toll can be attributed to four factors:

1) Greater understanding of the storm surge and better storm surge forecasts issued by the National Hurricane Center, thanks to such tools as the SLOSH storm surge model.
2) The excellent job NWS/NHC/FEMA and state and local Emergency Managers have done educating the public on the potential surge they can expect.
3) The success local government has had making evacuations of low-lying areas work.
4) Luck. The 20+ storm surge deaths on the Bolivar Peninsula in 2008 from Hurricane Ike show that there are still plenty of stubborn, unlucky, or uneducated people who will die when a significant storm surge hits a low-lying populated coast. The storm surge from the next major hurricane that sweeps through the Florida Keys is likely to cause a lot of storm surge deaths, since many residents there are pretty stubborn about not evacuating.

Kudos and links
I thank Ken Bass for providing the details on the Lincoln High storm surge near-disaster. Ken is working on a book on Hurricane Hugo, and has written a very readable book I plan to review later this year, about a fictional Category 4 hurricane hitting New York City.

Hurricanes-blizzards-noreasters.com has a web page with links to tons of Hurricane Hugo stories. Included are links to YouTube videos of a "Rescue 911" episode that interviewed survivors of the Lincoln High storm surge scare. The show also did a re-creation of the event.

Our Historical storm surge page has SLOSH model storm surge animations of Hurricane Hugo's landafall, as well as of 39 other famous hurricanes.

Tomorrow: I'll wrap up my series on Hurricane Hugo.

Jeff Masters

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Good Evening!! Tropics are taking a break and WOW, look at that lovely SQUALL line!! Hopefully that meso quiets down, Nashville, TN has had 8.23" of rain this mo, 5TH Wettest since 1871 records beagn!!

Got my first 24hr ban for posting an off topic video!! Has BLOG D/T'S most of the day!!

No more off topic videoes for me!!
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825. JLPR
98L looking very interesting
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Quoting iceman55:
wow that kind krazy


yeah, he will be missed :(
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Quoting pottery:
Greetings. From trinidad, 11n 61w.
Is it still September ? I cannot remember a drier looking Atlantic, Caribbean, GOM, in September. Or for most other months actually! What a peculiar season.
How many Invests have we had this season, that have fizzled out to nothing?
Not complaining, just find it very strange.
The season 2009 will be remember for Lots of SAL most of the season, dry air and lots of shear which for me is the main TC "Aquiles."
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Quoting iceman55:
tornadodude why what happen


didnt say, just that he will not be on anymore, and wishes all of us well
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Ok guys, I received a message from Grothar saying that he will not be on here anymore, and he wishes all of us well
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815. JRRP
Quoting iceman55:
JRRP so not strong

mmm... weak or moderated
i do not think will be strong
but one never know
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Quoting StSimonsIslandGAGuy:
I remember the snows of March 1980, March 1986 and December 1989. My avatar is from the house I grew up in on Christmas Eve, 1989.

What a beautiful place to grow up in.
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Quoting Chicklit:
Here it is...34.4, -94.5
TulsaRadar


here is the velocity, if you look wsw of Mena, you can see the rotation
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809. jipmg
Models showing a big canadian snow storm developing in a couple of days, possibly cold front all the way down into Florida
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808. JRRP
Quoting Chicklit:

um, what does that mean?

sorry... i meant mjo
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807. JRRP
Quoting iceman55:
JRRP strong mjo

i think will be moderated
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Here it is...34.4, -94.5
TulsaRadar
Member Since: July 11, 2006 Posts: 14 Comments: 11423
Quoting PcolaDan:

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR...
SOUTHEASTERN LE FLORE COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 1030 PM CDT

* AT 1000 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A
POTENTIALLY TORNADIC THUNDERSTORM WITH STRONG LOW LEVEL ROTATION 6
MILES EAST OF OCTAVIA...MOVING NORTHEAST AT 15 MPH. THIS IS A
DANGEROUS STORM...A TORNADO IS OCCURRING OR COULD FORM AT ANY TIME.

* THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
INDICATED COUNTY...


uh oh!
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This could be a long night for that area. Look at pic Chicklit posted and these may become common.

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR...
SOUTHEASTERN LE FLORE COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 1030 PM CDT

* AT 1000 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A
POTENTIALLY TORNADIC THUNDERSTORM WITH STRONG LOW LEVEL ROTATION 6
MILES EAST OF OCTAVIA...MOVING NORTHEAST AT 15 MPH. THIS IS A
DANGEROUS STORM...A TORNADO IS OCCURRING OR COULD FORM AT ANY TIME.

* THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
INDICATED COUNTY...
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Quoting JRRP:

mojo is coming

um, what does that mean?
Member Since: July 11, 2006 Posts: 14 Comments: 11423
802. jipmg
I find it crazy 98L is resisting such strong shear..
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yowza.
Link
Member Since: July 11, 2006 Posts: 14 Comments: 11423
799. JRRP
Quoting iceman55:




mjo is coming
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Quoting Chicklit:
To add to that 1900:


The list is looong.

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Our local WU forecast an hour ago went from scattered showers to expect deadly lightning and hail, and 40mph winds.

Downdrafts/microbursts are what I'm pondering.

There hasn't been any observable moisture from anywhere all day, but I guess there is?

This is from a hot, dry day here in CenTX.
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prayers for the folks in Georgia where severe flooding is occuring.
goodnight!
Member Since: July 11, 2006 Posts: 14 Comments: 11423
Quoting StormW:


I don't think it will. Shear is forecast to increase over it in the next 24-36 hours.

Should move slowly WNW, then eventually catch a deep trof in about 72 hours.
Thank you. Just saw that it was looking pretty healthy tonight.
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To add to that 1900:

The green's are flood watch, flood warning.
The blue is high wind advisory.
Yellow severe thunderstorm.
Orange is fire warning.
Link
Member Since: July 11, 2006 Posts: 14 Comments: 11423
Sure is alot going on here:

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pcoladan, don't be surprised when you get a 24-hr. ban for that...i got my first in 4 years after posting a pic of The Enterprise last weekend.
anyway, 98L appears to be making a comeback.

Loop
Member Since: July 11, 2006 Posts: 14 Comments: 11423
Quoting StSimonsIslandGAGuy:
I remember the snows of March 1980, March 1986 and December 1989. My avatar is from the house I grew up in on Christmas Eve, 1989.
I have a picture of my 1968 Camaro with 2 inches of snow and a top coating of ice while in Gainesville, Florida from that storm.
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Quoting tornadodude:


well it has been alright so far, definitely getting more difficult, but I am really enjoying my EAS class. how is it in Slidell?


mail!!!!
Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting Yalahaman:
Seen it three times in 30 yrs. in central FL. No accumilation just falling flakes.
snow is snow
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Florida snowfall events since 1900 (from Wiki cause I am being lazy):

December 16, 1901: Light snow is reported in Jacksonville
February 7, 1907: Downtown Jacksonville receives light snow flurries in the early afternoon.
November 27, 1912: An overnight period of snow covers the ground and trees with a 0.5-inch (12.7 mm) layer in northern Florida.
January 22, 1935: Snow falls until the next morning, with Pensacola recording 1 inch (25 mm)
February 2, 1951: Snowfall begins and ends the following day, accumulating to about 2 inches (51 mm) in Saint Augustine and Crescent City.
December 14, 1952: Sleet and snow falls across the northern portion of the state, though there is very little accumulation.
December 14, 1953: Light sleet occurs in the morning in Marianna.
March 28, 1955: Snowfall accumulates to about an inch in Marianna along the Florida Panhandle.
February 13, 1958: An overnight rainfall changes to snowfall in Jacksonville and accumulates to about 1.5 inches (38 mm). Additionally, Tallahassee reports a record 2.8 inches (71 mm).
February 9, 1973: Snow falls over the northern portion of the state, including a total of two inches (51mm) in Pensacola, with unofficial reports of up to 8 inches (200 mm).
January 17, 1977: The pressure gradient between a strong ridge over the Mississippi Valley and a Nor'easter over Atlantic Canada sends very cold temperatures southward into the state. Areas around Pensacola are the first to receive the snow. By early on January 19, West Palm Beach reports snow for the first time on record, with snow flurries reaching as far south as Homestead. The snow causes little impact as it quickly melts, though the accompanying cold air results in hundreds of millions of dollars in damage and several deaths. On January 20, the Miami Herald reports the event as the front page story, with a headline of a size usually reserved for the declaration of war.
Late January, 1977: Pensacola receives snowfall.
March 2, 1980: A quarter of an inch (6mm) of snow covers car tops and patio furniture in Jacksonville.
January 17, 1981: Reports indicate snowfalls in Fort Lauderdale and Miami.
March 1, 1986: 0.5 inches (13 mm) of snow accumulates overnight in Jacksonville before melting within 30 minutes due to the morning sun.
December 23, 1989: Light rain in Jacksonville turns to freezing rain as temperatures drop, and later changes to snow. The snow totals several inches in some locations, and results in the first White Christmas in the city's history.
March 12, 1993: The '93 Superstorm produces up to 4 inches (100 mm) of snow along the Florida Panhandle.
January 8, 1996: Snow flurries are reported from Crystal River to New Port Richey with no accumulation.
December 18, 1996: A plume of cold air causes snow to form in the northwestern portion of Escambia County
January 24, 2003: A plume of Arctic air produces widespread record low temperatures and light snow flurries along the eastern coastline. The snow is described as ocean effect snow, identical to lake effect snow in that it occurs due to very cold air passing over relatively warm water temperatures. The snow reaches as far south as Fort Pierce. No accumulation is reported due to rising temperatures throughout the day.
December 25, 2004: Locations along the Florida Panhandle receive a dusting of snow.
November 21, 2006: An eastward moving weather system produces a very light dusting and snowflakes in central Florida. It is the first snow in November in the state since 1912.
February 3, 2007: Very light snow flurries are reported in the Panhandle, lasting less than an hour.
April 8, 2007: Portions of the western Florida Panhandle receive brief durations of sleet.
December 25, 2007: Sleet, occasionally mixed with snow, is reported in portions of the western Florida Panhandle. The sleet lasted about 30 minutes before becoming a thunderstorm with rain, sleet, and hail.
January 3, 2008: Light snow flurries are reported near Daytona Beach.
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I was living in Fort Pierce in 1977 when snow fell and accumulated to about 1 inch. It was a wild thing after just moving to Florida from New Jersey.
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Here's my Wunderground 4cast for 78641:

Now
A band of thunderstorms in central Texas is developing southeastward at 15 mph toward Burnet and Llano counties. This activity will reach Valley Spring, Tow and oakalia around 11 PM. Expect deadly cloud to ground lightning, hail, winds gusting to 40 mph and up to an inch of rain.
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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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