CLS, a has Con : Cag Res. Geecks Kee. CERCA 2

TECHNICAL REPORT CERC-87-11

US Army Corps HURRICANE DANNY STORM SURGE DATA

of Engineers

Report 4
by
Andrew W. Garcia, William S. Hegge

Coastal Engineering Research Center

DEPARTMENT OF THE ARMY
Waterways Experiment Station, Corps of Engineers
PO Box 631, Vicksburg, Mississippi 39180-0631

eanivaraanic

NS oes, Institution

August 1987
Report 4 of a Series

Approved For Public Release, Distribution Unlimited

Prepared for DEPARTMENT OF THE ARMY
US Army Corps-of Engineers
Washington, DC 20314-1000

Under Hurricane Surge Prototype Data Collection
Work Unit 321-31662

Destroy this report when no longer needed. Do not return
it to the originator.

The findings in this report are not to be construed as an official
Department of the Army position unless so designated
by other authorized documents.

The contents of this report are not to be used for

advertising, publication, or promotional purposes.

Citation of trade names does not constitute an

official endorsement or approval of the use of
such commercial products.

2S nclassi ied

SECURITY CLASSIFICATION OF THIS PAGE

Form A r
REPORT DOCUMENTATION PAGE OMBING Oren olga
Exp. Date Jun 30, 1986
la REPORT SECURITY CLASSIFICATION 1b. RESTRICTIVE MARKINGS
Unclassified

2a. SECURITY CLASSIFICATION AUTHORITY 3. DISTRIBUTION/ AVAILABILITY OF REPORT

2b. DECLASSIFICATION/ DOWNGRADING SCHEDULE

4 PERFORMING ORGANIZATION REPORT NUMBER(S)

Approved for public release; distribution
unlimited.
5. MONITORING ORGANIZATION REPORT NUMBER(S)

Technical Report CERC-87-11

6a. NAME OF PERFORMING ORGANIZATION
USAEWES, Coastal Engineering
Research Center
. ADDRESS (City, State, and ZIP Code)
PO Box 631

Vicksburg, MS 39180-0631

6b. OFFICE SYMBOL
(if applicable)

7a. NAME OF MONITORING ORGANIZATION

7b. ADDRESS (City, State, and ZIP Code)

. NAME OF FUNDING/SPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER
ORGANIZATION (If applicable)

US Army Corps of Engineers

. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS See reverse

PROGRAM PROJECT TASK WORK UNIT
Washington, DC 20314-1000 Sige ins! | bic} a0

ACCESSION NO.
TITLE (include Security Classification)

See reverse

Hurricane Danny Storm Surge Data

12. PERSONAL AUTHOR(S)
Garcia, Andrew W.; Hegge, William S.
13a. TYPE OF REPORT Z 13b. TIME COVERED 14. DATE OF REPORT. (Year, Month, Day) ]15. PAGE COUNT
Report 4 of a series} eroy 1985 qo 1986 August 1984 y
16. SUPPLEMENTARY NOTATION
Available from National Technical Information Service, 5285 Port Royal Road, Springfield,

COSATI CODES

SUBGROUP

18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number)
Hurricane Danny (LC) Storm surges (LC)
Hurricanes (LC)
Ocean waves (LC)
19. ABSTRACT (Continue on reverse if necessary and identify by block number)

A summary of storm surge high-water mark, hydrograph, and wave data acquired during
and subsequent to Hurricane Danny is presented. Of particular interest are the wave data
taken from an offshore oil platform located only 10 miles from the track of the hurri-
cane. The data were obtained and assembled as part of a long-term research effort by the
US Army Corps of Engineers to establish a quantitative data set with the objective of
providing, in a series of documents, the data necessary for simulation and verification
of numerical surge models. The data contained herein were obtained primarily by the US
Army Engineer Waterways Experiment Station and the US Army Engineer District, Galveston,
with supplemental data from contributing agencies and institutions. Additional informa-
tion is included in the form of photographs and descriptive narrative to aid investiga-
tors in assessing the degree of importance of an individual measurement for the purpose
of model verification.

20. DISTRIBUTION / AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION
Gd UNCLASSIFIED/UNLIMITED =) same as RPT. (CJ oric users Unclassified
22a. NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (Include Area Code) | 22c. OFFICE SYMBOL

DD FORM 1473, a4mar 83 APR edition may be used until exhausted. SECURITY CLASSIFICATION OF THIS PAGE
All other editions are obsolete. a
Unclassified

WOONONA

0 0301 OO91eb4 6

Unclassified
SECURITY CLASSIFICATION OF THIS PAGE

10. SOURCE OF FUNDING NUMBERS
WORK UNIT ACCESSION NO. (Continued).

Hurricane Surge Prototype Data Collection Work Unit 321-31662

SECURITY CLASSIFICATION OF THIS PAGE

PREFACE

The information and data presented herein were assembled and analyzed
from 1985 to 1986 by authorization from the Office, Chief of Engineers (OCE),
Coastal Engineering Area of Civil Works Research and Development, as a mission
requirement of the Hurricane Surge Prototype Data Collection Work Unit 321-
31662. Messrs. John H. Lockhart, Jr., and John Housley are the OCE Technical
Monitors for the Coastal Engineering Research Area.

The work unit is a multiyear project of the US Army Engineer Waterways
Experiment Station (WES), Coastal Engineering Research Center (CERC), under
general supervision of Dr. James R. Houston, Chief, CERC; Mr. Thomas W.
Richardson, Chief, Engineering Development Division; and Dr. Dennis R. Smith,
former Chief, Prototype Measurement and Analysis Branch (CD-P). Dr. Charles L.
Vincent is CERC Program Manager. Mr. Andrew W. Garcia, CD-P, is the Principal
Investigator of the Hurricane Surge Prototype Data Collection work unit, and
Mr. William S. Hegge, CD-P, is the engineer in charge of data collection
activities. This report was prepared by Messrs. Garcia and Hegge and edited
by Ms. Jamie W. Leach, Information Products Division, Information Technology
Laboratory, WES.

This report is fourth in a series. Reports 1-3 provided similar data on
Hurricanes Chris, Alicia, and Elena, respectively.

Commander and Director of WES during report publication was

COL Dwayne G. Lee, CE. Technical Director was Dr. Robert W. Whalin.

CONTENTS

PINRDNGING 6556606000000000000000000000000006000000000000000000000009000500

CONVERSION FACTORS, NON-SI TO SI (METRIC)
UNITS OF MEASUREMENT... cece cccccccvcvcccsccccrcscssscccscssececccas

BART mes IONPUOW IG ON 6 6.566005000000000000000000000000000000000500000000
PART II: METEOROLOGICAL DISCUSSION... 2... ccc ccs crcccccrcscccccrcercccs
PART TEI: HYDROGRAPHIC DATA... 2... ccc cw cere eee enc vce rece scvssccevcecs
PART IV: WWANW3, IDYMIWN 5909 00060000000000000000000000000000000000500000000
PART V: LOSMESUOIY, WIV G 66a GgdodD00000DD0 G0 00000000000 000000000000500
PART VI: CONCLUSTON. 660 oo ccc cc wc vce cle oo v0 00 010 010010 01s 010 vs10.0 01s) 0 80) sees ele
PHOTOS 1-10

PLATES 1-20

APPENDIX A: WAVE SPECTRA... 2... cccccvccccvccccccccccccccscvccscscecccens

Al

CONVERSION FACTORS, NON-SI TO SI (METRIC)
UNITS OF MEASUREMENT

Non-SI units of measurement used in this report can be converted to SI

(metric) units as follows:

Multiply By To Obtain
feet 0.3048 metres
knots (international) 0.5144444 metres per second
miles (US statute) 1.609347 kilometres
millibars 100.0000 pascals

HURRICANE DANNY STORM SURGE AND WAVE DATA

PART I: INTRODUCTION

1. This report is the fourth in a series* providing a data base
directed toward verification of numerical storm surge models. As such, the
emphasis is on quantitative measurements of the hydrodynamic and meteorologic
parameters of Hurricane Danny rather than on documentation of structural dam-
age or changes in coastal morphology. The wave data contained in Part IV were
obtained by a US Army Engineer Waterways Experiment Station (WES), Coastal En-
gineering Research Center (CERC), wave gage located on Shell Oil Company Plat-
form Vermilion 22 located at latitude 29°28.2' N, longitude 92°33.0' W. The
eye of Danny passed very near Vermilion 22, resulting in a rare opportunity to
acquire locally generated hurricane wave data. These data are included to
permit assessment and verification of hurricane-generated wave models.

2. Contained herein are coastal and inland hydrographs and basic meteo-
rological data associated with Hurricane Danny. These data have been compiled
from a variety of sources; consequently, they cannot be guaranteed to be abso-
lutely accurate. Nevertheless, every reasonable effort has been made to en-

sure the data are as consistent and complete as possible.

* Thomas H. Flor. 1983 (Jul). ''Poststorm Reconnaissance of Tropical Storm
Chris," Miscellaneous Paper HL-83-5, US Army Engineer Waterways Experiment
Station, Vicksburg, Miss.

Andrew W. Garcia and Thomas H. Flor. 1984 (Nov). "Hurricane Alicia Storm
Surge and Wave Data," Technical Report CERC-84-6, US Army Engineer Waterways
Experiment Station, Vicksburg, Miss.

Andrew W. Garcia and William S. Hegge. 1987. '"'Hurricane Elena Storm Surge
Data,'' Technical Report CERC-87-10, Report 3, US Army Engineer Waterways
Experiment Station, Vicksburg, Miss.

PART II: METEOROLOGICAL DISCUSSION

3. Hurricane Danny was identified as a poorly defined tropical depres-
sion on 12 August 1985 while located just south of the western tip of Cuba.*
The minimum central pressure at the time was a relatively high 1010 mb.**
During the next 24 hr, the central pressure increased slightly to 1011 mb.,
and the system showed little change in organization or strength. By the morn-
ing of 14 August, the depression had passed through the Yucatan Straits into
the Gulf of Mexico. The central pressure began dropping, and the winds rap-
idly increased to tropical storm speed of 35 knots. During the following
24 hr, the storm intensified very rapidly, reaching hurricane intensity early
on the morning of 15 August 1985. Danny was then located about 225 miles
south of New Orleans, La., moving toward Port Arthur, Tex. During the day,
the hurricane assumed a more northerly course and made landfall late during
the evening of 15 August 1985, just east of Grand Chenier, La.

4. Danny was classified as a minimal hurricane, a Category 1 on the
Saffir-Simpson scale, which ranges from a minimum of 1 to a maximum of 5. The
hurricane attained its greatest intensity at the time of landfall with maximum
sustained winds of about 90 mph and a minimum central pressure of 987 mb.
Danny weakened rapidly after moving inland across Louisiana and within 20 hr
had weakened to a tropical depression. An unusual feature of Danny's movement
through the Gulf of Mexico was the remarkably constant speed of translation
during the 2 days prior to landfall. From 1200 Greenwich mean time (Gmt)

13 August to 1200 Gmt 15 August, 12-hr averages of Danny's forward speed
ranged from 13.2 mph to 14.2 mph. The distances traversed during four 12-hr
intervals beginning at 1200 Gmt 13 August were 170, 159, 158, and 160 statute
miles. Average speeds for these distances were 14.2, 13.2, 13.2, and

13.3 mph, respectively. Figure 1 shows the approximate track of Danny.

Table 1 contains the preliminary best-track information.

* The meteorological discussion and information contained in Table 1 are
taken from the preliminary report on Hurricane Danny provided by the
National Hurricane Center.

*k A table of factors for converting non-SI units of measurement to metric
(SI) is presented on page 3.

LEGEND

0000 GMT

1200 GMT

HURRICANE

TROPICAL STORM
TROPICAL DEPRESSION

Figure 1. Approximate track of Hurricane Danny.

Table 1

Preliminary Best Track - Hurricane Danny
12-20 August 1985

Time Position, deg Pressure Wind
Date Gmt Latitude Longitude mb knots Stage
8/12 0000 1G65) 80.7 1010 DS) Tropical depression
8/12 0600 19) 2 81.4 1010 25
8/12 1200 18) 8) 82.1 1010 25
8/12 1800 20.5) 82.9 1011 25)
8/13 0000 Pil o ik 83.7 1011 DS)
8/13 0600 Dil oF 84.6 1011 DS
8/13 1200 DD 53) 85.6 1011 30
8/13 1800 23.0 86.7 1011 30
8/14 0000 2301 87.8 1010 35) Tropical storm
8/14 0600 24.4 88.8 1007 45 Tropical storm
8/14 1200 Zao 89.8 1004 50 Tropical storm
8/14 1800 2559 M067 1001 60 Tropical storm
8/15 0000 26.8 Qi 5 997 70 Hurricane
8/15 0600 278 922 995 15 Hurricane
8/15 1200 23-9) 92.6 988 80 Hurricane
8/15 1800 30.0 9267 988 70 Hurricane
8/16 0000 Sil 50 OD oth 992 50 Tropical storm
8/16 0600 32.0 92.0 997 40 Tropical storm
8/16 1200 32.9 91.4 1000 30 Tropical depression
8/16 1800 336 7/ 90.4 1002 30
8/17 0000 34.63} 89) 52 1004 30
8/17 0600 34.7 87.8 1006 30
8/17 1200 35.0 86.3 1008 30
8/17 1800 3543} 94.8 1010 30
8/18 0000 3550 83.4 1011 25
8/18 0600 3556) 82.0 1011 25
8/18 1200 36.0 80.6 1012 DS)
8/18 1800 36.3 V9) G2 1012 25
8/19 0000 BOo7/ V7 32) 1012 25 Extratropical
8/19 0600 37) oi 76.6 1012 725)
8/19 1200 SD UD oS 1012 25
8/19 1800 38.0 74.0 1013 25
8/20 0000 38.5 Vod 1013 20
8/20 0600 39) 5 1 TiS 1014 20
8/20 1200 S9Ry/ 70.4 1014 20
8/20 1800 40.4 69.4 1014 20
Minimum Pressure
8/15 1620 29.6 Poll 987 80 Hurricane
Landfall
8/15 1630 29.6 Moll 987 80 Hurricane

PART III: HYDROGRAPHIC DATA

5. The impact of the storm surge generated by Danny was minimal due to
the relatively low intensity of the hurricane and landfall being in a remote
and sparsely populated area of the Louisiana coastline. Moreover, much of the
reach of coastline affected by Danny is shallow swampland which tended to
dissipate the surge before it reached populated areas. Figures 2-4 show the
locations of hydrographs covering the reach of coastline from Cameron, La., to
the Rigolets near Slidell, La. Table 2 is the index to the tide gage loca-
tions. The hydrographs are contained in Plates 1-20. Table 3 is a listing of
the maximum water elevations recorded at each hydrograph location.

6. Significant increases in water levels associated with the storm were
confined to approximately 60 miles of coastline extending westward from
Atchafalaya Bay to Pecan Island, La. These increases are evident in
Plates 3-10, all of which were obtained within the previous reach of coast-—
line. The highest water level recorded was 7.7 ft, relative to NGVD, which
occurred at Lukes Landing just north of Point Chevreuil, La. (Plate 7). Other
high-water levels were recorded at Vermilion Lock, east (7.1 ft, Plate 5),
Freshwater Bayou Lock (6.7 ft, Plate 3), and Atchafalaya Bay, Eugene Island
(6.7 ft, Plate 9).

IM V1

TLIHM

j-y suorzeo0T surses)

5 yeaa”
e=
Shes

a IE

°Z ean3staq

cE)

Bujsseob

sigan =,

uoiaweg

—~—O
yeas slow

Lf <<

; ep a ongia u

N-H suotTj}e00T Bur3e9 °¢ eANnsTY

) [ xe S| W Bl O

| p-o5se) |
i

AVa All

4 iva

ANNOFH fcld dl

39434 3417011M 4)
TWNONLYN SA3M 173HS ($*

Id punoyw
qd 4ines i,

/
(ses
=F uty ae

: Joosdsaiem ;

jomA|}O
uaosaud +

JHONY 14

Us
a LSM Z
CVATYS pue seu Caan (va ;
Re f
: =
m7 5 \\ p a4 i
. . 14 b uapyeo |
ey TNC ER Ba ere |
Joan of 2
, VA ee pay il i Oy UIPHUeL i
YL SS a ; i i
biewiany seq, am ah es a, : angi jainey Ss daibeqearz— ee eg) é

Se

pate vi
p _ynao} page Ose | eres flee
Apes : “\ ¥ \sexaien J { ; x
hts . ; (
Wie 1S ; = Loca Ne (
A pais f AW Se AC EE ehgueuear Pues! Aron)
ae , en , NK > ;

10

MM

LAKE PO

—_—oor a - eS
oe oS

|Comfort |

=,Pt Lydia

*\Chicot |

Grand Gosier |

Ag R 3 ~ —
ea Sees = 2 ea:
See aN Nene ~. & N AS / BRETON NATIONAL |
= Port sulotun a) - S S CG 2 yf 7 WILOLIFE REFUGE |
Bea eee DEK BESS SEE =< Tef

SSS
Breton |

“SDEET A, AALIONS L

STP apy i

ast rimsauice’ iy
NATIONAL wiLoLIE REruce
Timbalier |

©
CG O

Figure 4. Gaging locations O-U

11

Table 2

Index to Tide Gage Locations

Figure No. Location Gage Title
2 A Calcasieu Pass, La.
2 B Vermilion 22 platform, La.
2 C Schooner Bayou control structure, La.
2 D Freshwater Bayou Lock (South), La.
2 E Vermilion Lock (West), La.
2 F Vermilion Lock (East), La.
2 G Vermilion River, at Bancker, La.
3 H Lukes Landing, La.
3 I Calumet, La.
3 J Atchafalaya Bay, Eugene Island, La.
3 K Eugene Island, N-62, La.
3} 1b Sweet Bay Lake, La.
3 M Round Bayou at Deer Island, La.
3 N Bayou Petit Caillou at Cocodrie, La.
4 O Bayou Lafourche at Leeville, La.
4 P Grand Isle, La.
4 Q Venice, La.
4 R Southwest Pass, La.
4 S Head of Passes, La.
4 T Port Eads, La.
4 U Lake Borgne at Rigolets, La.

12

Location

Calcasieu Pass, La.
Grand Chenier, La.

Schooner Bayou Control

Structure, La.

Freshwater Bayou Lock 6.

(South), La.*

Table 3

Times and Heights of Maximum Elevations

Max. Water Elev.,

Vermilion Lock (West), La. 2
Vermilion Lock (East), La. 7
5

Vermilion River at
Bancker, La.

Lukes Landing, La.*

Calumet, La.

Atchafalaya Bay, Eugene

Island
Eugene Island, N-62
Sweet Bay Lake, La.
Round Bayou at Deer
Island, La.
Bayou Petit Caillou
at Cocodrie, La.
Bayou Lafourche at
Leeville, La.
Grand Isle, La.
Venice, La.
Southwest Pass, La.
Head of Passes, La.
Port Eads, La.

Lake Borgne at Rigolets,

La.

Note: CDT
NGVD

CE

NOS

Corps

Central Daylight Time.
National Geodetic Vertical Datum.

of Engineers.

National Ocean Service.

* Incomplete record.

ft

13

Time, CDT/Date

0630/15/08/85
Unknown
1600/15/08/85

1230/15/08/85

1800/15/08/85
1400/15/08/85
1700/15/08/85

1000/15/08/85
1200/15/08/85
1000/15/08/85

1100/15/08/85
1230/15/08/85
1230/15/08/85

1000/15/08/85
1300/15/08/85

0830/15/08/85
1000/15/08/85
0830/15/08/85
0900/15/08/85
0900/15/08/85
1130/15/08/85

Datum Source

NOS

PART IV: WAVE DATA

7. Wave and tide gages on the Shell Oil Company platforn,

Vermilion 22, were being operated by CERC during Danny's passage through the
Gulf of Mexico. The location of Vermilion 22 latitude is 29°28.2' N,
longitude 92°33.0' W, and the water depth is about 9 m. At the point of clos-
est approach, the eye of Danny was within 10 miles of Vermilion 22. Figure 5
is the hydrograph of observed and predicted tides at the location of Vermil-
ion 22. Figure 6 is a plot of observed minus predicted water levels.

8. Wave measurements were made using a self-contained, internal-
recording pressure gage. The wave data were spectrally processed via a Fast
Fourier Transform algorithm and corrected for depth attenuation effects ac-—
cording to linear wave theory. Figure 7 is a plot of the significant wave
height for 13-17 August 1986, corresponding to the approximate time of passage
of Danny. The greatest significant wave height occurring during Danny's pas-—
sage was 9.71 ft with a period at the spectral peak of 9.5 sec. Appendix A
contains plots of the wave spectra observed at 1030 on 14 August 1985 to 1030
on 16 August 1985. The spectra contained in Figures A2-Al3 are characteristic

of the evolution of a storm-generated sea state.

14

DIFFERENCE, FT

DEPTH, FT

VERMILION 22 OFFSHORE OIL PLATFORM

13 14 15 16 17 18 19
AUGUST 1985

Figure 5. Hydrograph, observed and predicted tides,

Figure 6.

Shell Oil platform, Vermilion 22, La.

VERMILION 22 OFFSHORE OIL PLATFORM

AUGUST 1985

Difference between observed and predicted tides,
Shell Oil platform, Vermilion 22, La.

15

3.000

M

2.250

1.500

SIGNIFICANT WAVE HEIGHT,

0.750

0.000
13.0

Figure 7.

RESULIS FRGM PROGR SP it
HURRICANE SURGE PROJECT
VERKIULITGNS S/N ES), JUN = RUG S&S
14.0 SO 16.0 L75@ 18.

CALENDAR DATE
AUGUST, ISes

Significant wave height, Shell Oil platform, Vermilion 22, La.

16

PART V: POSTSTORM SURVEY

9. The poststorm survey of high-water marks and damage caused by Danny
was conducted during 10-17 August 1985. The photos contained herein include
both ground-level and aerial views.

10. Wind damage was the most evident sign of the hurricane's passage in
the western part of Louisiana. Photo 1 shows metal sheeting stripped from the
sides and roof of the Crain Brothers building at Grand Chenier, La. Just east
of Grand Chenier, near Pecan Island, La., utility poles lay on the ground
alongside the road (Photo 2). Just north of Pecan Island on Highway 82E, the
roof was torn from a mobile home and deposited alongside it (Photo 3).

ll. Farther east in Louisiana, there was evidence of surge damage in
addition to wind damage. At Intracoastal City, La., a line of debris ona
fence indicated the high-water mark was approximately 3 ft above ground level
(Photo 4). At the site of the air logistics base just north of town, 1 ft of
water was still standing at the time of the survey (Photo 5). There was wide-
spread wind damage in this area, as shown by the collapsed farm equipment shed
that was located nearby (Photo 6). Combined wind and surge damage was also
evident east of Intracoastal City. In Cypremort Point, La., the metal siding
of a boathouse was wind damaged (Photo 7), and a nearby trailer sustained
surge damage (Photo 8). The surge was estimated to be about 2 ft above ground
level which was enough to tear the metal siding and displace the air
conditioning unit on the trailer.

12. The aerial survey of Grand Isle, La., revealed a large amount of
flooding, but it is uncertain if the flooding was caused by coastal surge or
local rainfall. The most definite evidence of surge was seen on the beaches
on the southern side of Grand Isle where debris lines and beach scarps were
clearly visible (Photo 9). A closeup of the beach scarp (Photo 10) shows the
height of the cut into the beach slope to be 3 to 5 ft above normal tide

level.

17

PART VI: CONCLUSION

13. Hurricane Danny was the second Atlantic and the first landfalling
hurricane of the 1985 season. Classed as Category 1 on the Saffir-Simpson
scale, it reached maximum intensity just prior to landfall with an estimated
maximum windspeed of about 90 mph and observed windspeeds of 70 mph or more in
all quadrants. The surge generated by Danny was confined primarily to
Vermilion and Atchafalaya Bays. Eastward of Atchafalaya Bay, surge levels
exceeded the predicted tide by about a foot or less. However, within
Vermilion and Atchafalaya Bays, surge levels as much as 5 ft above the ex-
pected astronomical tide were recorded. Surge levels diminished rapidly with
distance inland, and the poststorm survey indicated only communities located
on the periphery of Vermilion and Atchafalaya Bays to be significantly
affected.

14. Wave data acquired at the Vermilion 22 platform during Danny should
prove particularly useful for verification of numerical wave models. The
close passage of Danny to Vermilion 22 resulted in rapidly varying wave condi-
tions, a particularly severe test of the growth, propagation, and decay algo-

rithms used in wave models.

18

Sanrereentaoe
Sap tr AABN 8 0 AEN itis en

St ee >

Photo 1. Damaged metal sheeting on Crain Brothers building,
Grand Chenier, La.

Photo 2. Downed utility poles near Pecan Island, La.

19

Photo 3. Mobile home roof damage near Pecan Island, La.

Photo 4. Debris line on fence, Intracoastal City, La.

20

Photo 5. Residual flooding of the air logistics base near
Intracoastal City, La.

Photo 6. Collapsed farm equipment shed near
Intracoastal City, La.

21

Photo 7. Damaged metal sheeting on a boathouse,
Cypremont Point, La.

Photo 8. Surge damage to mobile home, Cypremont Point, La.

22

Photo 9. Debris line and beach scarp, southern shore of
Grand Isle, La.

Photo 10. Beach scarp, southern shore of Grand Isle, La.

23

S8 LSNSNG
Sil Sil

=
—D
=
|
yu)
Iau
Ge
va
<=
aD)
=
©
Zz
‘
4
|

“66H NalrGuaiws

G8 LSN3NG
oil Sl

"W1 “SYNLONYLS TOYLNOD NOAYG YSNOOHIS

=
=D)
ri
(9)
0)
Ga
Gr
]
a
=)
=
S)
Zz
‘o
7
=]

PLATE 2

S8 LSN9Ne’
SI Sl

C

£

v

=
=)
=
eva
70
(]
Fz
]
<=
=D)
4
(>)
Zz
mu
A

“© CE AMOS MAO MOE) SEIS ae

PLATE 3

68 TSh3ie
Sit Sl

El (Sah) S07 NOMA

c

£

v

S

=
—D
4
7
AO
(])
a
Gal
<
ald)
=
O
ZS
‘o
4
Cae

PLATE 4

“el

7

6

(

G8 LSN3Ne

SII

ISb4

)

Si

M007 NOT TVIWYSA

=
—D
—
])
A
|
eS
[ea
<
—D
Ce
O
rue

6

i

PLATE 5

S8 ISN3Ne
ST Gl

"Y7 “YSNONUG LY YSATY NOITINYSA

=
—D
YJ
(3)
A
(ov)
tS
al
<=
—D
Hj
@S
Zz

6

ie

PLATE 6

S8 LSN3Ne
Slt Si

=
—D
4
7
AO
])
i
]
<=
=D)
=
(S|)
=
‘e
Sal
tae

"47 “SNIONYT S3YNT

Sie) JUSS
Sil S|

HT nw

G

£

v

S

2
—D
=|
[])
eo)
])
cS
1]
<—
—D
4
CO
CE

he

PLATE 8

Se} ISAAK
SI Sl

6 é

ET INS IS I sINSISINS) ~ Nel) eYNel Tel stellate!

=
=D
4
(ea)
0)
7]
er
™
<
=D
=]
OS)
ZZ
‘
4
=

PLATE 9

Sts) AES file

=
—D
r4
(eva)
AO
ae)
S&S
Ga
<=
—D
ial
=)
ZEB
‘o
a
Hj

"b1 “@9-N “ONBISI SNISAT

Sie} IESIMeiils
oi Sl

é

te abil) Nets) JLSTSIMS

=
—D
=
[aul
A
")
a
ol
<=
—D
=)
(©)
a
‘

Wha

PLATE 11

S8 ISNond
Si SI

"U7 “ONYISI Y399C LY NOAWE GNNOY

Gg

o

v

S

=
—D
4
)
A
7
=
7
<=
—D
cae]
=)
ZS

ds

PLATE 12

3 TSH3aie
oil Sill

"b1 “SIYCO909 LY NOVO LIL3d NOAvE

=
D
4
cm
>a
m
aL
m
<
2D
=

]

14 “NO

PLATE 13

SS) IUSINSINE
il SI

eq) “2a iNe We SOMO nove

=
SD)
a)
[)
AO
(oy)
ie
fy)
<=
—D
tone!
S)
Zz
“o
7
—)

PLATE 14

S8 LSN3INY
QT Sl

"47 “S1SI ONYNI

2S
—D
4
tual
Po)
[")
i
|
<
—D
Taal
S
Z
“
a
=

PLATE 15

Se SAIS
S)I, oa

=
—D
4
1)
AO
77
Ce
(C3)
EE
-D
Loar
&)
ZZ
‘
“4
=

"A SSN

S8 ISN3Nb
Sil Sl

ET SSH LSEMEWUAOS

=
—D
|
(4
A
a)
=
[aol
=<
—D
ri
Ss
PE
‘oe
4
4

PLATE 17

S8 LSNgany
S)) Sl

"UT °S3iSSHd 40 OyaHy

=
—D
re
cu]
0)
]
Ee
Er]
=<
—D
oe)
—
S)
ZZ.
‘eo
aaa
4

PLATE 18

Ge ISMN
oi Sil

=
=)
cies
0)
om

y 5
LBAS

I

g S
ii Ne

"EL PSG) Sted

Si} US Neale

"U7 “SISIO9IY Lb JNIYOY Jy

PLATE 20

APPENDIX A: WAVE SPECTRA

Al

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

RECORD NOS =438
DATE = 8-14-85 AT 1030
GiSiea Mes 0.6054

PEAK FREQ, HZ = 0.2383
PEAK PER, SEC = 4.1967

-000 BE, HZ = 0.0078
DOF = 16

0.000 0.100 0.200 0.300 0.400 0.500
, FREQUENCY, HZ

Figure Al. Wave spectrum, Shell Oil platform,
Vermilion 22, at 1030, 14 August 1985

. 000
RECORD NOS =439
DATE = 8-14-85 AT 1330
Sh Mie= 0.8702
PEAK FREQ, HZ = 0.2617
PEAK PER, SEC = 3.8209

. 000 BE, HZ = 0.0078
DOF = 16

. 000

. 000

. 000

0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure A2. Wave spectrum, Shell Oil platform,
Vermilion 22, at 1330, 14 August 1985

A2

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY OENSITY,

RECORD NOS =440

DATE = 8-14-85 AT 1630
HS, M = ho W977
PEAK FREQ, HZ = 0.1055
| PEAK PER, SEC = 9.4815
.000 BE, HZ = 0.0078
DOF = 16
-000
.000
“aaa een es sie ail J
0.000 0.100 0.200 0.300 0.400
FREQUENCY, HZ
Figure A3. Wave spectrum, Shell Oil platforn,
Vermilion 22, at 1630, 14 August 1985
-000 -

RECORD NOS =4U1

Figure A4.

DATE = 8-14-85 AT 1930
HS, M = 1.1073
PEAK FREQ, HZ = 0.0898
L PEAK PER, SEC = 11.1304
ooo Bee iiZe— 0.0078
DOF = 16
- 000 '
bull
000 sf =I ——— |
0.000 0.100 0.200 0.300 0.400 0.500
FREQUENCY, HZ

Wave spectrum, Shell Oil platform,
Vermilion 22, at 1930, 14 August 1985

A3

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

. 000

RECORD NOS =44e

FREQUENCY, HZ

DATE = 8-14-85 AT 2230
HS, M = 1.2892
PEAK FREQ, HZ = 0.0820
PEAK PER, SEC = 12.1905
.000 BE, Wz s 0.0078
DOF = 16
.000 -
.000 |
es eee ee
000 IC
0.000 0.100 0.200 0.300 0.400 0.500
FREQUENCY, HZ
Figure A5. Wave spectrum, Shell Oil platforn,
Vermilion 22, at 2230, 14 August 1985
.000 —
RECORD NOS =4Wu3
DATE = 8-15-85 AT 130
HS, M = 1.5654
PEAK FREQ, HZ = 0.0820
PEAK PER, SEC = 12.1905
+500 BE. Hze= 0.0078
DOF = 16
.000 |
.500
.000
0.000 0.100 0.200 0.300 0.400 0.500

Figure A6. Wave spectrum, Shell Oil platform,

Vermilion 22, at 0130, 15 August 1985

A4

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY.

10.000 -

RECORD NOS =444

DATE = 8-15-85 AT 430
HS, M = 2.15U7
Peel FiRte@, Fz = Oo iiss}
PEAK PER, SEC = 8.8276

7.500 + BE, Hz = 0.0078
DOF = 16

5.000

2.500 -

0.000

0.000 0.100 g.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure A7. Wave spectrum, Shell Oil platform,
Vermilion 22, at 0430, 15 August 1985

10.000 -—
RECORD NOS =445
DATE = 8-15-85 AT 730
HS, ft = 25 12S)
PEAK FREQ, HZ = O. 1992
PEAK PER, SEG = 5.0196
7.500 = Ble, (d= 0.0078
DOF = 16
SOON
2.500 in
0.000 aS ile al ee a eee eee |
0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure A8. Wave spectrum, Shell Oil platform,
Vermilion 22, at 0730, 15 August 1985

A5

10.000

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

RECORD NOS =446

DAVE = Boils Fy Oso
HS, M = 1.4370
PEAK FREQ, HZ = 0.1133
PEAK PER, SEC = 8.8276

7.500 Bea tliZen= 0.0078
DOF = 16

5.000

2.500

0.000
0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure A9. Wave spectrum, Shell Oil platform,
Vermilion 22, at 1030, 15 August 1985

- 000
RECORD NOS =4U7
DATE = 8-15-85 AT 1330
WS5 tS 2.9588
PEAK FREQ, HZ = 0.1055
PEAK PER, SEC = 9.4815
- 500 BEraahZa= 0.0078
DOF = 16

.000

.500

- 000
0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure Al0. Wave spectrum, Shell Oil platform,
Vermilion 22, at 1330, 15 August 1985

A6

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

. 000

-000 -—
RECORD NOS =448
DATE = 8-15-85 AT 1630
nS, Il = 1.8056
PEAK FREQ, HZ = 0.1289
PER PER, SEC = 7. 7578

500 BE, HZ = 0.0078
DOF = 16

go00 -

500 if

- 000

0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure All. Wave spectrum, Shell Oil platforn,
Vermilion 22, at 1630, 15 August 1985

RECORD NOS =4U9
DATE = 8-15-85 AT 1930

t= al

HS, M = 1.2301
PEAK FREQ, Hz = 0.1523
L PEAK PER, SEC = 6.5641
ooo BE, Wz < 0.0078
DOF = 16
.000 F
. 000 I
.000
0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure Al2. Wave spectrum, Shell Oil platform,
Vermilion, 22 at 1930, 15 August 1985

A7

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

-000 —

-000

.000

.000

.000

0.000

Figure Al3.

-000

.000

-000

000 --

Figure Al4.

0.100 0.200
FREQUENCY,

HZ

RECORD NOS =450

DATES es —Somaleaeso
HS, M = 0.7665
PEAK FREQ, HZ = 0.1836
PEAK PER, SEC = 5.4468
Bey Wz = 0.0078
DOF = 16

J

0.300 0.400 0.500

Vermilion 22, at 2230, 15 August 1985

0.100 0.200
FREQUENCY,

HZ

RECORD NOS =451
DATE = 8-16-85
iso. TM €

PEAK FREQ, HZ

PEAK PER, SEC
BE, Hz =
DOF =

0.300 0.400

Vermilion 22, at 0130, 16 August 1985

A8

Wave spectrum, Shell Oil platform,

AT 130
0.8259
OFsIDNSS
8.8276
0.0078
1G

Wave spectrum, Shell Oil platform,

4.000 -

M2/HZ

ENERGY DENSITY,

M2/HZ

ENERGY DENSITY,

RECORD NOS =4S2
DATE = 8-16-85 AT 430
WS. f= 0.9625
PEAK FREQ, HZ = 0.1992

i PEAK PER, SEC = 5.0196

000 BE, We = 0.0078
DOF = 16

-000 F

000 |

-000 — — ===

0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure Al5. Wave spectrum, Shell Oil platform,
Vermilion 22, at 0430, 16 August 1985

. 000
RECORD NOS =453
DATE = 8-16-85 AT 730
HS, M = 0.8655
PEAK FREQ, Hz = 0.1914
PEAK PER, SEC = 5.22uS
.000 BE, Hz = 0.0078
DOF = 16

- 000

. 000

. 000
0.000 0.100 0.200 0.300 0.400 0.500

FREQUENCY, HZ

Figure Al6. Wave spectrum, Shell Oil platform,
Vermilion 22, at 0730, 16 August 1985

AY

M2/HZ

ENERGY DENSITY,

. 000 -

O00NS

-000 |

RECORD NOS =45U

DATE = 8-16-85 AT 1030
So Ml € 0.7316

PEAK FREQ, HZ = 0.1758

PERN Pet, SEG = So Sey)

BE. Hz = 0.0078

DOF = 16

0.100 0.200 0.300 0.400
FREQUENCY. HZ

Figure Al7. Wave spectrum, Shell Oil platform,

Vermilion 22, at 1030, 16 August 1985

A10

7 Th : eres it ; ti
aa vet
Rh a i 7

Pine,

Pp Bah
Sg
}

7 : i Hr! We.
cry,