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

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

Share this Blog
1
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 428 - 378

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

Quoting btwntx08:

rocky mtns,colorado,between grand junction east and its happening right now


Thank you!

Member Since: March 10, 2006 Posts: 0 Comments: 10798
@424, this time of day is the diurnal minimum for convection over water.
Member Since: Posts: Comments:
Quoting StormW:
Just for giggles and grins, anyone interested, scroll below the satellite shot, click animation, zoom factor high, and click on the convection SE of Fred-ex.

Back later

NASA


Interesting Indeed Storm W.

As the convection wanes it's giving us a good shot under the deck and looks like to me, by trailing the low level clouds, the MLC is or in process of working down to the surface.
Member Since: Posts: Comments:
not to change the subject but can anyone give me an idea of why Fredex looks as if it just dissipated in the last few hours? Is this the opposite of the Diurnal max? Sorry if my terms are not precise .... Will Fredex make a comeback tonight during the max?
Member Since: Posts: Comments:
Texas Drought Situation
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting FLGatorCaneNut:


I've been in vail in mid July with a dusting of snow


That was probably cocaine.
Member Since: March 10, 2006 Posts: 0 Comments: 10798
Quoting rwdobson:


High country of Colorado usually only has about 15-20 frost free nights all year...so it can snow almost anytime...except maybe July and August. I've been snowed on in June up there before.


I've been in vail in mid July with a dusting of snow
Member Since: Posts: Comments:
Ok. I should have elaborated. Where is COPPER MTN and I-70? (Country? City, State?) and WHEN. M238 AI doesn't help me here. It can be the hebrew calendar or julien, but M238 AI I can't read.
Member Since: March 10, 2006 Posts: 0 Comments: 10798
Quoting iceman55:



lot of snow


When and where is that iceman?
Member Since: March 10, 2006 Posts: 0 Comments: 10798
the thought of that blows my mind as well. Being that I have lived in hot,humid Florida my whole life. I would really like to get out west and snowboard sometime, Ive heard it's beautiful!
Member Since: Posts: Comments:
Quoting robie1conobie:
It actually snows during the summer on mt. hood in oregon. watching a snowboard show on t.v. the other day, they said it was the only refuge for people to ride in the u.s. during summer months; not trying to argue your point, just found that interesting.


High country of Colorado usually only has about 15-20 frost free nights all year...so it can snow almost anytime...except maybe July and August. I've been snowed on in June up there before.
Member Since: Posts: Comments:
4 years ago today, widespread panic was taking place in TX, which describes my screen name. Rita cranked up to 170mph late in the evening and all hell broke loose
Member Since: Posts: Comments:
400. JLPR
oh wait I forgot about Lenny in 99 and Debby in 2000 which were close calls xD

me and my broken brain lol
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting Grothar:


Thanks, never thought to look there. Looks like a wet week-end for us down here, eh>


Here as well. Said stalled front is supposed to draw in the moisture and rain for a few days. Up to 60% last I looked.
Member Since: Posts: Comments:
394. PcolaDan

Beautiful pic. Thanks for sharing. :) Kinda gets you in the mood for some cooler weather. Like my mom buying me my annual bag of candy corn. You know fall has arrived. :)
Member Since: Posts: Comments:
Quoting homelesswanderer:


This is what they say this afternoon.

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
300 PM EDT MON SEP 21 2009

HIGH PRES RIDGE IS ACROSS THE NORTHERN GULF OF MEXICO WITH
MOSTLY LIGHT WINDS ACROSS THE AREA. WINDS WILL INCREASE OVER THE
SE GULF TONIGHT AS A TROUGH IN THE ATLC MOVES WWD AND WILL
EXTEND ALONG 85W WED THEN SLOWLY DRIFT W INTO THE SW GULF FRI
AND W OF THE AREA LATE SAT. A WEAK COLD FRONT WILL MOVE TO THE
TEXAS COAST TUE EVENING. THE FRONT STALLS WED AND DISSIPATES
THU. WINDS GENERALLY 10-15 KT THROUGH THE END OF THE WEEK THEN
DECREASE 5-10 KT OVER THE WEEKEND.

SURFACE TROUGH EXTENDS FROM 31N72W TO 28N76W...REMNANTS FROM
FRED. A CLUSTER OF MODERATE TO STRONG TSTMS ASSOCIATED WITH THE
TROUGH IS N OF 27N BETWEEN 70W-74W. THE TROUGH WILL MOVE W AND
APPROACHE THE FLORIDA COAST LATE TUE THEN W OF THE AREA OVER
FLORIDA ON WED. A WEAK RIDGE BUILDS ACROSS THE AREA IN THE WAKE
OF THE TROUGH. WINDS WILL BE 15 KT OR LESS ACROSS THE AREA
THROUGH THE FORECAST PERIOD...WITH SEAS 5 FT OR LESS.


Thanks, never thought to look there. Looks like a wet week-end for us down here, eh>
Member Since: Posts: Comments:
Quoting StormW:


Would have to look at the update on the steering layers forecast tonight.


If I get to them first, I shall let you know. lol Thanks for the assistance.
Member Since: Posts: Comments:
I guess a better way to put it, this end washes out. Be nice to have a cold front. Hot around here.

94.8 °F
Clear
Humidity: 41%
Dew Point: 67 °F
Wind: 3.5 mph from the SSE
Wind Gust: 4.0 mph
Pressure: 29.74 in (Steady)
Heat Index: 99 °F
Visibility: 10.0 miles
UV: 7 out of 16
Clouds: Clear -
(Above Ground Level)
Elevation: 79 ft
Member Since: Posts: Comments:
Quoting tornadodude:


From NWS
BUT LITTLE OR NO ACCUMULATION IS EXPECTED IN THESE AREAS.


Member Since: Posts: Comments:
393. JLPR
Quoting jurakantaino:
Yes interesting to notice that shear is the main factor for inhibiting systems, to develop.


yep, also the fact that 98L fell apart even with mostly favorable conditions :| including the anticlone in top of it
I guess 98L just didn't want to form lol
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Ike, I don't think its the same front. I'm west of where they show that front going into Florida.
Member Since: Posts: Comments:
391. JLPR
Quoting tornadodude:


wow, my mistake, I spaced and was thinking of Jamaica xD


xD
I think the hurricane that has passed the closest and has been felt somewhat was Dean in 07
but it was only some winds with a little rain, in the north I mean xD the south must have gotten a bit more
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting JLPR:
remnants of 98L still spinning


and that's about it
Fred-Ex convection is dissipating and the blob close to the islands is under shear
this has been a very quiet peak =]
Yes interesting to notice that shear is the main factor for inhibiting systems, to develop.
Member Since: Posts: Comments:
It actually snows during the summer on mt. hood in oregon. watching a snowboard show on t.v. the other day, they said it was the only refuge for people to ride in the u.s. during summer months; not trying to argue your point, just found that interesting.
Member Since: Posts: Comments:
388. IKE
Quoting homelesswanderer:


I think our cold front is supposed to stall just north of us and dissipate into the weekend. And cause a lot of rain. Houston was the last hold out among the locals talking about the strong cold front. Now I think they're giving up too. Lol. I also noticed the lows in the GOM and BOC on that model too. Hope they stay that way. Just lows.


You better look again....

HPC has the front through me here in the Florida panhandle on day 6, which is Sunday....



And look at day 7...with a secondary front plowing toward the SE USA....and the first front down into central Florida....

Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting Grothar:


That was the model to which I was referring. Didn't want to post it, lest I was bombaded with "Where is the post" The model does not show the direction to which it would be steered, though. After the stall, I mean. Any thoughts?


This is what they say this afternoon.

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
300 PM EDT MON SEP 21 2009

HIGH PRES RIDGE IS ACROSS THE NORTHERN GULF OF MEXICO WITH
MOSTLY LIGHT WINDS ACROSS THE AREA. WINDS WILL INCREASE OVER THE
SE GULF TONIGHT AS A TROUGH IN THE ATLC MOVES WWD AND WILL
EXTEND ALONG 85W WED THEN SLOWLY DRIFT W INTO THE SW GULF FRI
AND W OF THE AREA LATE SAT. A WEAK COLD FRONT WILL MOVE TO THE
TEXAS COAST TUE EVENING. THE FRONT STALLS WED AND DISSIPATES
THU. WINDS GENERALLY 10-15 KT THROUGH THE END OF THE WEEK THEN
DECREASE 5-10 KT OVER THE WEEKEND.

SURFACE TROUGH EXTENDS FROM 31N72W TO 28N76W...REMNANTS FROM
FRED. A CLUSTER OF MODERATE TO STRONG TSTMS ASSOCIATED WITH THE
TROUGH IS N OF 27N BETWEEN 70W-74W. THE TROUGH WILL MOVE W AND
APPROACHE THE FLORIDA COAST LATE TUE THEN W OF THE AREA OVER
FLORIDA ON WED. A WEAK RIDGE BUILDS ACROSS THE AREA IN THE WAKE
OF THE TROUGH. WINDS WILL BE 15 KT OR LESS ACROSS THE AREA
THROUGH THE FORECAST PERIOD...WITH SEAS 5 FT OR LESS.
Member Since: Posts: Comments:
Quoting JLPR:


nope passed far away to the south :)


wow, my mistake, I spaced and was thinking of Jamaica xD
Member Since: June 28, 2006 Posts: 25 Comments: 8360
383. JLPR
Quoting tornadodude:


Ivan was a close call there :O


nope passed far away to the south :)
Member Since: September 4, 2007 Posts: 36 Comments: 5223
at the risk of sounding like JFVWS....Any thoughts on track and intensity?
Member Since: Posts: Comments:
Quoting JLPR:


lol
yep good idea :)


Ivan was a close call there :O
Member Since: June 28, 2006 Posts: 25 Comments: 8360
379. JLPR
Quoting homelesswanderer:


Lol. Sssshhh! Knock on wood. We thought we were done after Rita. We don't tempt fate around here any more. ;)


lol
yep good idea :)
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting StormW:


One of the models, GFS I believe, does develop a ridge over the top of him, off the coast, and stalls him along the coast. Let's hope not.


That was the model to which I was referring. Didn't want to post it, lest I was bombaded with "Where is the post" The model does not show the direction to which it would be steered, though. After the stall, I mean. Any thoughts?
Member Since: Posts: Comments:

Viewing: 428 - 378

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
37 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron