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HURRICANE CAMILLE - August 14-22, 1969
Worse than Katrina, Camille barely spared New Orleans from destruction
(Lessons we did not learn)

George Pararas-Carayannis

Excerpt from a study performed for the U.S. Army Coastal Engineering Research Center under contract with the U.S. Nuclear Regulatory Commission

INTRODUCTION

The year 1969 had an unusually large number of tropical storms that progressed in odd and abnormal patterns. One of those was a hurricane named Camille. In August 1969, Camille developed into one of the most devastating hurricanes in U.S. history up to that time. It raced across the Gulf of Texas, heading straight for New Orleans. Fortunately Camille changed direction, sparing New Orleans from destruction. Instead, it made landfall to the east, tearing into the coasts of Eastern Louisiana and Mississippi, and spreading death and destruction across its path. A total of 262 people lost their lives in seven states from Louisiana to Virginia. However, the total damage was very high at about $1.5 billion (in 1969 dollars) - most from extremely high hurricane surges (U.S. Army Engineer District, Mobile, 1970).

Camille's Evolution

The storm originated off the coast of Africa on 5 August 1969. It was recognized as a tropical disturbance on the 9th, when it was about 480 miles east of the northern Leeward Islands. By 14 August, near the island of Grand Cayman in the Caribbean, the storm had developed a 29.50 inches of mercury (999 millibars) pressure center and surface winds of 55 miles per hour. The disturbance was christened Tropical Storm Camille.

Tropical Storm Camille moved northwestward at 9 miles per hour and its central pressure dropped to 29.26 inches of mercury (991 millibars) late on the 14th. By 15 August, Camille was located 60 miles southeast of Cape San Antonio, Cuba, and had developed into a full hurricane with 28.47 inches of mercury (964 millibars) central pressure and winds of 115 miles per hour (DOE Angelis, 1969). The hurricane moved into the Gulf of Mexico on the 16th and changed to a north-northwestward direction with a translational speed of 14 miles per hour. By then, its central pressure had dropped to 26.72 inches of mercury (905 millibars).

Hurricane Watches Issued Westward to New Orleans

Hurricane watches were set up from Biloxi, Mississippi, to St. Marks, Florida. On 17 August, Camille was 250 miles south of Mobile, Alabama with surface winds near the center estimated at more than 201.5 miles per hour. Hurricane warnings were issued for the Mississippi coastal areas extending westward to New Orleans.

Hurricane Camille's 30-ft surface isovels (knots) as it neared landfall near New Orleans on August 17, 1969 (Source: Environmental Services Service Administration (HUR 7-113A, 1970)

Camille Makes Landfall at Waveland and Bay St. Louis, Louisiana.

The center of Hurricane Camille made landfall at Clermont Harbor, Waveland, and Bay St. Louis, Louisiana at about 2330 hours CDT on the 17th. There were no records of winds near the center, but estimates ranged up to 201.5 miles per hour. A Transworld oil rig platform tower recorded gusts up to 172-mph before failing.


At the west end of the Bay St. Louis Bridge a pressure of 26.85 inches of mercury (909.3 millibars) was reported. This is the second lowest barometric pressure ever measured in the United States. Only the 1935 Hurricane produced a lower pressure in the middle Keys of 892 Mb (26.35). At Boothville, Louisiana, winds of 107 miles per hour were recorded before a power failure; at Pilottown, Louisiana, the S.S. Cristobal estimated winds at 160 miles per hour. Winds at Keesler Air Force Base, Biloxi, Mississippi were measured at 81 miles per hour with gusts to 129 miles per hour. At Ingalls Shipyard, Pascagoula, Mississippi the highest sustained wind reached 81 miles per hour while a local radio station reported 104 miles per hour winds before power failure.

Overall it is estimated that Camille (a Category 5 hurricane) had sustained winds of 180 - 190-mph and gusts of as much as 210 - 220 mph.

Hurricane Camille's 30-ft surface isovels (knots) as it neared landfall near New Orleans on August 18, 1969 (Source: Environmental Services Service Administration (HUR 7-113A, 1970)

Flooding by Hurricane Camille's Surges

Hurricane-force winds were concentrated close to Hurricane Camille's center as it moved inland. These winds extended from east of New Orleans to Pascagoula, while gusts of hurricane force winds extended along the coast from New Orleans to west of Mobile Bay.

Hurricane Camille generated extremely high surges - the highest recorded in the U.S, up to that time. Storm surges flooded coastal regions from lower !laquemines Parish in Louisiana, to Perido Pass, Alabama. Maximum storm surge of 24.6 feet above MSL was measured in the Pass Christian-Long Beach, Mississippi, area. In St. Louis Bay, maximum surge was 18 feet above MSL. At Back Bay of Biloxi, Mississippi, the surge elevation reached about 15 feet above MSL (U.S. Army Engineer District, Mobile,1970), and near 10 feet above MSL as far east as the Mississippi-Alabama border.

Along the Louisiana coast, the storm surge was 15 feet above MSL at Boothville, and 9 feet above MSL near the mouth of the Mississippi, at Garden Island. At Alluvial City surge height reached 7.97 feet above MSL, at Chef Menteur Pass 11.06 feet, at Shell Beach 11.06 feet, and at Rigolets 9 feet. Detailed maps of areas flooded and surge measurements of Hurricane Camille can be found in the publication by Wilson and Hudson (1969). Additional surge elevations along the Louisiana and Mississippi coasts are shown in the adjacent figure.

Hurricane Camille track, windspeeds and resulting surges along the Mississippi Coast.

Surge data along the coast of Louisiana, Mississippi and Alabama, can be found in the U.S. Army Engineer District, Mobile Report (1970). The surge elevation of 19.5 feet above MSL used for the calibration of a mathematical model by the author of this article is based only on a visual observation of high water mark at Biloxi, Mississippi (see Figure below). This value may include runup due to wave action.

Destruction by Hurricane Camille and its Surges.

Most of the deaths and destruction were caused by Camille's storm surges. The destruction was unprecedented and left at least 15,000 people homeless. The entire infrastructure of the region was destroyed - roads, bridges, railaways and airports. Thousands of farm and domestic were drowned.

 

NOAA photo of destruction.

Camille Moves Inland

Once over land, Hurricane Camille weakened considerably moving northward through Mississippi, passing close to Columbia, Prentis, Jackson, Canton, and Greenwood. At Jackson, winds gusted to 67 miles per hour as the storm center passed 10 miles west of the city. Torrential rainfall caused devastating flash floods and landslides along the eastern slopes of the Blue Ridge Mountains and record flooding along the James River. Flush floods swept away roads, bridges, and buildings. More than 100 people were killed in Virginia and Tennessee. The storm weakened and was only identifiable as a depression by the time it reached the northern Mississippi border and was tracked northward to southern Virginia.

 

Camille's Path

 

Mathematical Modeling of Hurricane Camille' Surge at Biloxi, Missisippi.

A study of hurricane Camille was undertaken by Pararas-Carayannis (1975) for the purpose of verifying a mathematical model on the maximum hurricane surge flood as it compared with the observed maximum surge height observed at Biloxi, Mississippi. The following hurricane parameters were used for the calculation.

Central pressure - 27.63
Peripheral pressure - 2 9.92
Radius to Max. wind (naut. miles) - 14.0
Translation speed (knots) - 13.0
Maximum Gradient Wind (miles per hour) - 125.0

The surface wind fields and pressure fields of Hurricane Camille were obtained from the Hydro-Meteorological Reports HUR 7-113, and 7-113A (Environmental Science Services Administration (ESSA), 1969 and 1970). In the latter report wind fields were given at 6-hour intervals from 0000 hours through 1800 hours GMT, 17 August, then at 3-hour intervals through 0500 hours GMT, 18 August, and then at 6-hour intervals until 0000 hours GMT, 19 August (see isovel charts for 17 and 18 August 1969). These were the synoptic weather charts used in the modeling study. The map below shows the traverse for Hurricane Camille that was used for the calculation.

Computational Traverse

The traverse was selected to the right of Camille's track, to accommodate a limitation of the bathystrophic numerical model for surge computation (preferably at a distance of about 1-3 times the radius to maximum winds away from the path of the hurricane center and in order to intercept the maximum effect of the hurricane.

The traverse at Biloxi was selected as this location was on the open coast where large surge water levels were observed and documented and was nearer the tide gage at Pascagoula, Mississippi, where some tidal information could be obtained. Because of the Mississippi River Delta and the offshore islands, and the lack of sufficient wind field and hydrograph data, Biloxi was a poor site for the numerical calculations of surge. A better traverse may have been Pass Christian, Mississippi, where maximum surge for this hurricane occurred; however, it was not selected because of the unusual coastal configuration of the region and the presence of offshore islands.

The shore-intercept of the Biloxi traverse used in the computations was at 30°23'N, 88°52'W. It began 77 nautical miles from the shore at a depth of 600 feet on the Continental Shelf - using mean low water (MLW) as the reference datum. The bathymetry for the profile was taken from detailed nautical charts. The traverse's orientation was S 12°E. The bearing was established by a perpendicular orientation to the offshore bathymetric contours.

The landfall track for Hurricane Camille and the traverse used for the calculation of maximum surge height.

Other Computational Parameters

It is outside the scope of this report to present details of the computation. However there were a number of corrections applied for water level datum and phase of the predicted astronomical tide - in reference to MLW. The astronomical tide at the time of maximum surge inundation at Biloxi was determined to be 1.60 feet above MLW. Other hydrographic data of major importance in the calculation of the maximum storm surge involved the estimate of the initial rise in water level preceding the arrival of Camille. Such water level deviationscan be as much as 2 feet.

The initial rise used as input to the numerical calculation of the storm surge was the average difference between the predicted astronomical and the observed tide at or closest to the shore-intercept point (on an open coast) of the traverse before the influencing effects of hurricane winds and pressures. This initial rise was estimated to be 1.2 feet at Biloxi. In the numerical calculations this value was treated as a constant and added to the total water level. This may have been an oversimplification, since the cause for such initial rise or its exact magnitude during the passage of the storm is not known with certainty. This could also account for the difference found between observed and computed maximum surge flooding at Biloxi.

Finally, values of relative wind stress k, and bottom friction, K, coefficients were applied to the numerical equations used for the surge computation. The constants K1 and K2 that were used account for pressure, density, precipitation, temperature and other factors of a hurricane system, which are not easily measured, and can only be obtained empirically.

 

Results of the Computation

There was inadequate correlation between the computed hurricane surge hydrograph and the observed high water elevation at Biloxi. This was attributed to insufficiency of accurate wind-field information and the irregularity of the coastline. Furthermore, Camille's wind-field charts were available for only 6-hour intervals and the highest surge occurred sometime between the times shown in these charts. Furthermore, in 1969, there were no synoptic measurements of hurricane winds or satellite imagery - as readily available presently.

 

Observed and computed surge hydrographs for Hurricane Camille at Biloxi, Mississippi with datum corrections and optimal bottom frictional coefficient and surface wind stress.

 

Additionally, the interpolated wind field for that period that was used in the calculation probably did not accurately represent actual wind conditions, which produced the maximum surge. Similarly, there was no operating tide gauge and therefore no hydrograph at the point of the coast where the maximum surge occurred. As mentioned previously, the nearest tide gage station from which a partial record of this event could be obtained, was at Pascagoula, Mississippi. The peak surge provided as maximum at Biloxi for this location (19.5 feet above MSL) was based on a visual observation. The value was based on an observed elevation extrapolated from debris and high water marks and may have included the effects of wave-induced run-up. A more accurate value for Biloxi would be 20.4 feet. In the case of the Biloxi traverse the numerical model tended to overestimate the hurricane surge height, by about 15%. However, given the uncertainty of the wind data, this deviation is statistically acceptable. With good synoptic wind data, satellite imagery, better determination of hurricane parameters and modern fast computers, present mathematical models can estimate the maximum hurricane surge with greater accuracy.

 

REFERENCES

ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION, "Preliminary Analysis of Surface Wind Field and Sea-Level Pressures of Hurricane Camille, August 1969," Hydrometeorological Branch, HUR 7·113, Rockville, Md., Nov. 1969.

ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION, "Revised Surface Wind Field (30 ft.) of Hurricane Camille in Gulf of Mexico August 1969,"
Hydrometeorological Branch, HUR 7-113a, Rockville, Md., Mar. 1970.

Pararas-Carayannis, G. 1975, Verification Study of a Bathystrophic Storm Surge Model. U.S. Army, Corps of Engineers Coastal Engineering Research Center, Washington, D.C., Technical Memorandum No. 50, May 1975.

U.S. ARMY ENGINEER DISTRICT, MOBILE, "Hurricane Camille, 14-22 August 1969," Mobile, Ala., May 1970.

WILSON, K. V., and HUDSON, J. W., "Hurricane Camille Tidal Eloods of August i969, Along the Gulf Coast, Biloxi' Quadrangle, Mississippi," Atlas HA-395-408, U.S. Geological Survey, Washington, D.C., 1969.

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