Hurricane Andrew: Natural Disaster Survey Rpt, U.S. Dept Commerce, 1993

8/9/2019 Hurricane Andrew: Natural Disaster Survey Rpt, U.S. Dept Commerce, 1993

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Natural Disaster Survey Report

Hurricane Andrew :

South Florida and Louis iana

Au gu st 23-26, 1992

U.S. DEPARTMENT OF COMMERCE

National Oceanic an d Atmospheric Administration

Nat iona l Weather Service, Silver Spring, Mar ylan d


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Cover: Left photograph & Houstons WSR-88D, 0107 UTC, August 26, 1992; Right

photograph&

Melbournes WSR-88D, 0106 UTC, August 24, 1992.


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Natural Disaster Survey Report

Hurricane Andrew :

South Florida and Louis ianaAu gu st 23-26, 1992

Novem ber 1993

U.S. DEPARTMENT OF COMMERCE

Ronald H. Brow n, Secretary

National Oceanic an d Atmospheric Administration

D. J am es Baker, Administra tor

Nat iona l Weather Service

Dr. Elbert W. Friday, J r., Assistant Administra tor


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ACKNOWLEDGMENTS

The outstanding efforts of our National Oceanic and Atmospheric Administration (NOAA)

employees ensu red t he sa fety of millions of citizens in t he pa th of th is count rys most dest ru ctive

storm . The Nat iona l Weath er Service (NWS) sta ff thr oughout south Florida, and lat er inLouisian a, worked long hour s un der ph ysically and em otiona lly stressful conditions. I a m deeply

moved by the dedication of those most affected, specifically those in and around south Dade

Coun ty. Man y of our people lost a ll or pa rt of th eir homes an d their per sonal belongings, and

some were displaced for m onth s after t he storm. Yet th ey, as well as other F ederal, sta te, an d

local employees, remained at their post in the worst of conditions, putting the public welfare

ahead of their own safety.

Once again , I congr at ulat e th ose wh o made NOAAs response t o this powerful storm a success

story. You ar e an insp ira tion to us all.

Dr. Elbert W. Friday , Jr.

Novem ber 1993


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PREFACE

The primar y purpose of this disaster survey ha s been to evaluat e th e performa nce of the NWS

in fulfilling its mission of providing timely warnings and accurate forecasts for Hurricane

Andr ew. The responsibilities of NOAA, the par ent a gency of th e NWS, are broader . The NWSproducts an d services ar e key to severe storm pr eparedness a nd t he m itigation of its impa ct:

its SLOSH (Sea, Lake, an d Overland Su rges from H urr ican es) models a re u sed by emergency

evacuation planners; its wind speed measurements are used to develop building codes and to

design buildings; and its war nings an d forecasts a re instr um enta l to placing a tim eta ble on

implemen ting prepar edness actions an d response efforts. But NOAAs part ner ship role with

sta tes in m an aging th e Na tions coasta l zone, NOAAs tr ust ee responsibility for ma rine

resour ces, and oth er a gencywide concern s compel NOAA to step outs ide of the t ra ditiona l NWS

form at in th is preface to commen t on Hu rr ican e Andr ews consequ ences in south Florida an d

Louisiana.

NOAA and th e NWS ar e dedicat ed t o a continu ing improvement in wa rnings a nd forecast s,

th ereby allowing emergen cy ma na gemen t officials lead t ime to tak e lifesaving action. But , if

disastrous consequences are t o be mitigat ed, the coast al zone a nd other a rea s at risk must be

ma na ged in r ecognition of th e awful threa t t o life an d property th at hu rr ican es pose.

Hu rr ican es, of cour se, ar e nat ur al met eorological events. In th e a bsen ce of people an d their

property, hur rican es expend th eir force against ma rine an d terr estrial ecosystems tha t a dapt

to the storm s destruction. People and th eir property, un fort un a tely, ar e not a s resilient a s

da m aged ecosystem s. Hu rr ican es frequ ent ly ha ve cau sed significan t loss of life an d ma ssive

dam age t o property a nd n at ura l resour ces at trem endous cost both to public an d private sectors.

Until the past 30 years, however, areas vulnerable to hurricanes have been relatively

undeveloped; vacation beach houses were "beach shacks" or "cottages," easily rebuilt after a

storm . Urba n a nd subu rba n development wa s confined to relat ively few area s, often limited inits lan dward sprea d by wetlands.

The rush to the sun belt in t he 1960s, 1970s, and 1980s funda ment ally cha nged Coast al Plains

demograp hics. Beach cott ages were r epla ced by million dollar dwellings, and subu rba n an d

ur ban development becam e more extensive along th e coast an d extended much furth er inland.

Hur rican es Hugo and Andrew ha ve been th e most costly storm s in history largely becau se th ere

is now more development in place to dam age an d destroy. Given cur ren t development pa tt ern s

an d tr ends a long th e coast , we can an ticipate both dam ages an d costs to increase with futu re

storms. We would do well to heed the wa rnings th at population growth a nd land use pra ctice

in the N at ions Coasta l Plains ha ve set a sta ge for a series of hurr ican e disast ers an d associated

economic consequen ces of un precedent ed proport ions. For exam ple:

Populat ions ha ve grown explosively in coast al ar eas over the past 30 years. This growth

ha s crea ted t he obvious logistical problems associated with wa rn ing an d safely tra nsportin g

ever-increa sing nu mber s of resident s out of ha rm s way or to adequ at e shelters. Th is

inordinate burden is leading to evacuation times in some areas of the country that are

double the effective warning times t ha t t he Na tiona l Hurr ican e Center (NHC) can provide.

Ther e ar e oth er difficulties as well: t her e ar e significan t coast al populat ions wh ich h ave n ot


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experienced a hurricane and may be less able to prepare for one and respond properly

before, during, an d after the event. In ur ban a nd suburba n ar eas, even the best organ ized

governmen t r esponse m ay be un able to meet n eeds for shelter, food, and water .

Developm en t h a s been concentr at ed on bar rier islan ds and in coasta l flood plains. Such

development almost never relates to natural geographic or geomorphic limits of areasvulnerable to hurr ican es. In m ost places, infra stru ctur e is designed an d subdivisions a re

app roved without reference to th e need t o eva cuat e low-lying area s quickly. Coast al

constr uction setbacks, where th ey exist, often ar e inadequa te t o accomm odat e t he st orm

surge of a ma jor hur rican e. Stru ctu res employ architectur al designs , mat erials, an d

techniques that cannot withstand hurricanes. In booming communities vulnerable to

hu rr ican es, local building depar tm ent s often a re un able or unwilling to keep pace with code

enforcement & even if th ere is a n a dequa te code to enforce.

These problems a re exacerbated by continu ed destruction of an d interference with n at ura l

protective feat ures: beaches, dunes, tidal wetlands, man groves, an d the like. Many sta te

an d local planners a nd emergency ma na gers now underst an d the importan ce of a h ealthy

beach/dune syst em a nd m aint aining it by limiting so-called "ha rd" erosion cont rol structu resan d following regular m ainten an ce progra ms; man y oth ers do not.

Hurricane Hugo

In 1989, Hurr ican e Hugo foresha dowed the scale of hu rr ican e disast ers yet to come. Aft er

dealing a ser ious blow to the Ca ribbean , including Puer to Rico an d th e Virgin Islan ds, the m ajor

force of the storm h it the ma inlan d United Sta tes a t Ca pe Roma in Nat iona l Wildlife Refuge,

th en Fr an cis Mar ion Na tional Forest before wrea king havoc for ma ny miles inlan d. Despite

heavy dam age to Cha rleston a nd its environs, th e city largely was spa red& at least compa red

to th e devast at ion it would ha ve suffered ha d Hu gos eye come a shore 20 miles fur th er south .The sight of once beautiful vacation homes reduced to wind and water-borne debris along

Cha rlest on Count ys ba rr ier islan ds obscured t he fact t ha t H ugos wind effects could have been

far more significan t h ad t hey stru ck a more populated a rea.

In t he wind da ma ge along t he South Car olina coast, Hu go also provided a glimpse of building

code an d engineering issues. Myrtle Beach was well nort h a nd ea st of th e storm s ma jor effects,

but st ructur es there t ha t ha d been designed to withst an d winds significan tly great er th an those

actually experienced performed poorly. Other ar eas suffered becau se South Carolina h ad n o

sta tewide building code or h ur rican e resista nce stan dar ds (an d does not to this day) or becau se

local building codes were not en forced adequ at ely. The a lmost complete destr uction of mobile

homes in the path of the storm served notice once more that mobile homes are no place to be

during severe weath er.


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Hurricane Andrew

Andr ew defines the current problem: the m ajority of th e da ma ge was inland, outside of the

prim ar y storm su rge ar eas wher e emergen cy prepar edness a nd response officials usua lly focus

their at ten tion. Much of the coast al development in th e past 30 years ha s been outside

hur rican e sur ge zones but well with in wind zones.

Alth ough Andr ew cau sed significan t flooding da ma ge immediat ely adjacent to th e coast, wind

dam age caused m ost of th e devasta tion. Wat er, in the form of storm su rge an d flooding, still

poses the greatest threat to public health and safety as local authorities must be able to

evacuat e the population at risk in time. After all, ha d the topogra phy of Cut ler Ridge not

impeded th e storm sur ge, it would ha ve affected a rea s mu ch furt her inla nd. Still, Andrew likely

will prove th e norm for fut ur e storms ra th er th an t he exception: winds will pose a ver y

significan t t hr eat to life an d sa fety an d cause a ma jor percenta ge of property da ma ge.

In den sely populated a rea s, it is all but im possible to evacua te for wind. Forecast ers cann ot yet

predict wind fields accurately, and the large numbers of residents that would need to be

evacua ted to ensur e an adequa te m ar gin of safety would overwhelm r oads a nd shelters a lmostimmediately. On th e other ha nd, given extensive development in vulnera ble ar eas inland, no

longer can public officials afford to perceive hurricanes as merely flood/storm surge events.

Instea d, emergency preparedn ess officials and lan d use plann ers mu st consider hu rr ican es as

mu ch broader "wind/flood/storm su rge" events affecting ar eas ma ny miles inlan d. New

appr oaches a nd bu ilding codes mu st be developed t o prot ect t he pu blic. All of Florida, for

exam ple, must be considered vu lnera ble to the effects of hur ricanes, r egar dless of how far from

th e coast. All of its comm un ities should implemen t hur ricane prepar edness an d mitigat ion

policies.

Land Use Managemen t

Advan ces in technology ma y improve long-ra nge forecast ing, and Wea th er Su rveillan ce Rada r-

1988 Doppler (WSR-88D) is helping t o impr ove short-ter m wa rn ing an d forecas ting, but it is

unlikely th at lead t imes can be increased significan tly in th e near futu re. Curr ent lead times

cannot provide enough warning in many heavily populated areas to evacuate threatened

residents effectively.

NWS war ning capa bilities are only one side of th e equa tion for r educing thr eat s both to public

health a nd sa fety and to property. The oth er side is stat e and local governmen t a ctions th at

cont rol development in h ur rican e-prone ar eas a nd plan for an d car ry out eva cuat ions. Redefined

as wind/flood/storm surge events, h urr ican es present st at e a nd local plann ers with five a rea s

of focus in ad dition t o ongoing effort s.

Em ergency plan ner s primar y priority mu st be t o evacuat e resident s at risk from storm

sur ge an d other types of flooding, regar dless of the ext ent of a h ur ricanes potent ial wind

dam age. These residents remain th e m ost vulnerable to hu rrican es. Plan ners mu st

cont inu e to redu ce evacua tion times in area s vulnera ble to flooding from storm su rge. In

regions where development densities and patterns have outstripped the capacity of the


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ar eas infra stru ctur e to han dle evacuat ions, th e best th at can be hoped for is to minimize

the num ber of residents in su rge ar eas when th e storm h its an d to provide refuges of last

resort.

Officials need to ensure that adequate building codes are in place and that they are

vigorously enforced. Building codes in coast al a rea s n at ionwide should be r evised based onth e Andrew exper ience. Becau se ma ny stru ctu res were destr oyed when door or window

failures allowed wind pressu re t o demolish r oofs from t he in ter ior, codes need to emph asize

appr opriat e door an d window storm covers. Even a reas well inlan d must h ave hur rican e

resist an ce codes. Such codes should be enforced thr oughout t he St at e of Florida.

Regulations should be promulgated to require that new structures contain "hardened"

interior rooms to provide in-place hurricane shelters and require that, at a minimum,

mobile home pa rks h ave ha rdened sh eltering for a ll residents.

Sta te an d local officials need t o devise program s t o retr ofit existing bu ildings to pr ovide in-

place hardened sheltering and to bring substandard housing into compliance with a

hur rican e-resistan t code.

State and local officials need to revise land use planning, subdivision approval, and

perm ittin g processes to consider th e potent ial effects of severe st orms.

Hu rr ican e Andrew ha s given lessons to NOAA, too. For its pa rt , in a ddition to continu ing to

improve NWS warning and forecasting capabilities, NOAA will continue to work to make

Federa l hur rican e prepara tion a nd mitigation progra ms consistent. NOAA progra ms, with

relevance to coastal hazards mitigation, must work together more closely to provide better

services to sta te a nd other F edera l agen cies. As a beginn ing, th e Nat iona l Ocean Service (NOS)

currently is working to develop a response plan to provide needed immediate and longer term

products an d services to sta tes a fter coasta l disast ers. NOS a lso is developing new protocolsconsist ent with t he Feder al Response Pla n. Fina lly, NOAA will seek impr ovemen ts both in its

support for sta te coast al man agement pr ogram s and in th e program s themselves.

To address t he frighten ing poten tial consequ ences of increas ed hu rr ican e activity, NOAA seeks

a new par tn ership with st at es. Sta te an d local governmen ts, through nat ura l resource agencies,

boar ds, an d building inspectors, m ust work in collaborat ion with insu ra nce compa nies, building

indus tr ies, an d oth er privat e sector groups to minimize th e genera l populations exposur e to the

threats of hurricanes.


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FOREWORD

This report on H urr ican e Andrew was prepa red by th e DST a fter weeks of inter views and visits

to the damaged areas with Federal, state, and local officials in Florida and Louisiana.

Significan t inp ut also was provided by citizens in t he a ffected a rea s.

The DST is particularly grateful to the NOAA employees in the affected areas for their

assistan ce, despite th e extreme ha rdship endured by so ma ny of th e NOAA fam ily. We are

gra teful to the st at e a nd local officials an d repr esent at ives of relief agencies who took t ime from

ur gent dut ies to provide their impressions of the events du ring an d a fter the storms onslau ght.

We deeply appreciate the willingness of many citizens who shared their experiences with the

DST, despite th e complet e devast at ion of all their worldly possessions.

We comm end t he dedication an d professiona lism displayed by th e NOAA sta ff as well as other

Federal, state, and local employees who remained at their post under the most extreme of

condit ions, putt ing the pu blic welfar e ah ead of th eir own sa fety. While this docum ent is not

intended to chronicle the ent ire history of the storm a nd its after ma th , it assesses NOAAs

perform an ce an d recomm ends where impr ovements a re needed.

We acknowledge, with admiration and gratitude, the many people whose individual and

collective efforts sa ved th e lives of th eir fellow hu ma n beings. To all whose pa rt icipation m ade

the response to Hur rican e Andrew an overwhelming success, tha nk you.

The Disaster Survey Team


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TABLE OF CONTENTS

Page

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Disaster Survey Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

Summary of Findings and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

Hurricane Andrew : The Event and Its Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

P ART I: S OUTH FLORID A

Chapter I.A Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Chapter I.B Summary of P repa redness Act ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Ch apt er I.C NWS Con tin gen cy P la nn ing a nd Ba cku p Ar ra ngem en ts . . . . . . . . . . . 25

Ch apt er I.D Su mm ar y of NWS Wa tch es, Wa rn in gs, a nd Advisor ies . . . . . . . . . . . . . 29

Ch a pt er I.E S um m a ry of I nfor m a tion a nd Wa r nin g S er vices an d

Resp on s e Act ion s by E mergency Man agemen t an d Med ia . . . . . . . . . . 37

Chapter I.F Public Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Ch apt er I .G Process in g, In terp re ta t ion , an d D is semin a t ion of N WS

Informat ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Chapter I.H Communica t ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Chapter I.I Data Collect ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67


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P ART II: LOUISIAN A

Chapter II.A Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Chapter II.B Summary of Prepa redness Act ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Ch apt er II.C NWS Con tin gen cy P la nn ing a nd Ba cku p Ar ra ngem en ts . . . . . . . . . . 87

Ch apt er II.D Su mm ar y of NWS Wa tch es, Wa rn in gs, a nd Advisor ies . . . . . . . . . . . 91

Ch a pt er II .E S um m a ry of I nfor m a tion an d Wa r nin g S er vices a n d

Res pon s e Act ion s by E mergency Man agemen t and Media . . . . . . . . . 97

Chapter II.F Public Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Ch apt er II .G Process in g, In te rp ret a t ion , an d D is semin a t ion of N WS

Informat ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Chapter II.H Communica t ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Chapter II.I Data Collect ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

APPENDICES

Appendix A Summary Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Ap pen dix B F lor id a Dea t hs Dir ect ly At t ribu t able to H u rr ica n e An dr ew

August 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Appen dix C H ur rica ne An dr ew "Best Tr ack " Su mm ar y:

August 16-28, 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Appendix D Andrews Toll on Louisiana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Appendix E Louisiana Damage Descr ipt ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

Appen dix F In ter agen cy Coor din at in g Com m it tee on H ur r ica nes(ICCOH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1

Appendix G Saffir -Simpson Hurr icane Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1

Afterword


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ACRONYMS

AFB Air Force Base

AFOS Automat ion of F ield Opera t ions and Services

AOC Aircra ft Opera t ions CenterAOML Atlan t ic Oceanograph ic and Meteorologica l La bora tory

AP Associa ted Press

ASOS Automated Surface Observing System

AVN Avia t ion Model

AWIPS Advanced Wea ther In teract ive P rocessing System

BAM Beta Advect ion Model

BMS Bahamas Meteorologica l Service

CARCAH Ch ief Aer ia l Recon na issa nce Coor din at ion for a ll H ur rica nes

CDT Centra l Dayligh t Time

CLIPER CLImatology-P ERsistence hur r icane t racking m odel

CPA Closest Point of Approach

CPCS Common Program Cont rol Sta t ion

CWA County Warning Area

DEM Division of Emergency Management

DIFAX Digita l Facsimile

DMSP Defense Milita ry Sa tellite Program

DST Disaster Survey Team

EBS Emergency Broadcast System

EDT Eastern Dayligh t Time

EM Emergency Management

EOC Emergency Opera t ions Center

ET Electron ics Technician

FAA Federa l Avia t ion Administ ra t ionFEMA Federa l Emergency Management Agency

ft Feet

FTS Federa l Telephone System

GDS Graphic Decision System

GOES Geosta t iona ry Opera t ional Environmenta l Sa tellit e

GOES-Next GOES-Next Genera t ion Satellit e

HF High Frequency

HLS Hurr icane Loca l Sta tement

HPP Hurr icane P reparedness P rogram

HRD Hurr icane Research Division

ICCOH Interagency Coordina t ing Commit tee on Hurr icanes

kt s KnotsLALE TS Lou isia na La w E nfor cem ent Telecom mu nica tion s Syst em

LMRFC Lower Mississippi River Forecast Cen ter

MARS Milit a ry Affilia te Radio System

mb Millibars

MEOW Maximum Envelope of Water

Meteosa t Meteorologica l Opera t ions Sa tellit e

MIC Meteorologist in Charge


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MOU/A Memorandum of Understanding/Agreement

mph Miles per hour

MSL Mean Sea Level

NAWAS Nat ional Warn ing System

NDBC Nat ional Data Buoy Center

NE SDIS Na tion al E nvir on ment al Sa tellit e, Da ta , a nd In for ma tion Ser vice

NEXRAD Next Genera t ion Weather Radar

NFD Nat ional Forecast Division

NGVD Nat ional Geodet ic Ver t ica l Datum

NGWLMS Next Genera t ion Wa ter Level Measur em ent System

NHC Nat ional Hurr icane Center

NHC90 NHC 1990 Hurr icane Computer Forecast ing Program

NLETS Nat ional Law Enforcement Telecommunica t ions System

nm Naut ica l miles

NMC Nat ional Meteorologica l Cen ter

NOAA Nat ional Oceanic and Atmospher ic Admin ist ra t ion

NSSFC Nat ional Severe Storms Forecast Cen ter

NWR NOAA Weather RadioNOS Nat ional Ocean Service

NWS Nat ional Weather Service

NWSO NEXRAD Weather Service Office

NWWS NOAA Weather Wire Service

OEM Office of Emergency Management

OES Office of Ocean and Ear th Sciences

OIC Officia l in Charge

OSF Opera t iona l Suppor t Facility

PC Per sonal Computer

PUP Pr incipa l User Processor

QLM Quasi-Lagrangian Model

Rmax Radius of Maximum WindRFC River Forecast Center

RTA Remote Terminal to AFOS

SAB Synopt ic Analysis Branch

SELS Severe Loca l Storms Branch of NSSFC

SHIFOR Sta tist ica l Hurr icane In tensity Foreca st ing Model

SLOSH Sea , Lake, and Over land Surges from Hurr icanes

SRH Southern Region Headquar ters

SWIS Satellit e Weather In format ion System

SWODY1 Severe Weather Out look &

Day 1

SWODY2 Severe Weather Out look & Day 2

SWOMCD Severe Weather Out look &

Mesoscale Convective Discuss ionTCD Tropica l Cyclone Discussion

TCM Tropica l Cyclone Mar ine Advisory

TCP Tropica l Cyclone Public Advisory

TCU Tropica l Cyclone Update

TDL Techniques Development Labora tory

TROP AN Tr opica l Region al An alysis F acsim ile Cir cu it

TSAF Tropica l Sa tellit e Analysis and Forecast


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UGC Universa l Gener ic Code

UPI United Press In terna t ional

UPS Unin ter ruptable Power Supply

USACE U.S. Army Corps of Engineers

USAFR U.S. Air Force Reserve

USCG U.S. Coast Guard

USGS U.S. Geologica l Survey

UTC Coordina ted Universa l Time

VHF Very High Frequency

WCM Warning Coordina t ion Meteorologist

WMO World Meteorologica l Organ iza t ion

WPM Warning Preparedness Meteorologist

WSFO Weather Service Forecast Office

WSO Weather Service Office

WSR-57 Weather Surveillance Radar-1957

WS R-74(C,S ) Wea t her S u r veilla n ce Ra da r -1974 (C-ba n d, S-ba n d)

WSR-88D Weather Surveilla nce Radar-1988 Doppler

WWAMKC SE LS Sever e Loca l St or m Wa tch St at us Repor t


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DIS ASTER SU RVEY TEAM

SU RVEY TEAM LEADE R

Jen nifer J oy Wilson & Assistant Secreta ry and Deputy Administra tor,NOAA, U.S. Depart men t of Commer ce, Wash ington, D.C.

SU RVEY TEAM COORDIN ATOR

Ja mes P . Travers , Met eorologist & Director, Opera tions Division,

Weather Service Hea dquar ters, NOAA, Silver Spring, Mar ylan d.

Florida Team

Team Lead er, W. Sta nley Wilson , Oceanographer&

Assistant

Administra tor for Ocean Services an d Coastal Zone Ma na gement,

Na tional Ocean Service, NOAA, Washin gton, D.C.

Wil l iam O. Alexand er , Mesoscale Me teorologist&

Office of

Meteorology, Weath er Ser vice Hea dqua rt ers, NOAA, Silver Spr ing,

Maryland.

E. Ja y Bak er , Social Scientist an d Associate Pr ofessor& Depart ment of

Geograph y, Florida Sta te University, Tallaha ssee, Florida.

Bernard Pa lmer , Meteorologist in Cha rge & Weather Service F orecast

Office, NOAA, Columbia, South Carolina.

X. Wil l iam Proenz a , Met eorologist&

Deputy Director, N at iona l

Weather Service Southern Region H eadqua rter s, NOAA, Fort Worth,

Texas.

Kath y Sul l i van , Oceanographer & Chief Scientist-Designa te, NOAA,

Wash ington, D.C.

Herbert Lieb , Pu blic Affair s Consulta nt & National H urr icane Center,

NOAA, Coral Ga bles, Florida.

Will iam M. Fra nk , Met eorologist&

Depar tm ent of Meteorology, The

Penn sylvania St at e University, State College, Pennsylvania.

David McKinnie , Program Ana lyst & National Ocean Service/Office of

Ocean and Coastal Resource Management, NOAA, Washington, D.C.


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xiv

Timothy Goodspeed, Geogra pher & National Ocean Service/Office of

Ocean Resources Conservation and Assessment, NOAA, Washington,

D.C.

Mark Jacobsen , Living Mar ine Resources Specialist& Nat iona l Ocean

Service/Office of Ocean Resources Conserva tion a nd Assessment ,

NOAA, Washington, D.C.

Louisiana Team

Team Leader , Ned A . Os tenso, Geophysicist&

Assistant

Admin istr at or for Ocean ic and Atmospher ic Research, Office of Ocean ic

an d Atmospher ic Resear ch, NOAA, Wash ington, D.C.

Rain er Dombrowsky , Met eorologist&

Office of Meteorology, Weat her

Service Headquarters, NOAA, Silver Spring, Maryland.

Jerry McDuffie , Meteorologist in Cha rge & Weather Service F orecast

Office, NOAA, Los Angeles, Ca lifornia .

Thom as H. Gra yson, Met eorologist&

Chief, Systems Operations

Division, Na tiona l Weather Service Souther n Region Headqua rter s,

NOAA, Fort Wort h, Texas.

Wilson S ha ffer , Atm ospheric Scient ist&

Office of System s

Development, Weather Service Headquarters, NOAA, Silver Spring,

Maryland.

Chris topher R . Adam s , Social Scientist , Consu ltan t & Cooperative

Institu te for Research in t he Atmosphere, Colora do State University,

Fort Collins, Colorado.

Pat r ick J . Sla t t ery , Public Affairs Specialist & Nat iona l Weather

Service Central Region Headquarters, NOAA, Kansas City, Missouri.

Scot t Kroczynski , Hydrometeorologist & Office of Hydr ology, Wea th er

Service Headquarters, NOAA, Silver Spring, Maryland.

Mar k Ha nd el , Tropical Met eorologist, Consulta nt&

Cambridge,

Massachusetts.


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EXECU TIVE SU MMARY

The t ropical disturba nce tha t grew into Hurr ican e Andrew developed in th e centr al t ropical

Atla nt ic Ocean on August 16, 1992. Event ua lly a category 4 storm on the Sa ffir-Simpson Scale,

Andrew went on to inflict more dollar damage than any natural disaster in United Stateshistory. Upon its F lorida lan dfall at 5 AM Ea ster n Daylight Time (EDT) on August 24, wind

from Andrew was a susta ined 145 mph with gust s over 175 mph. Over a na rrow area , the storm

sur ge reached more th an 14 feet, with storm t ides a tta ining nea rly 17 feet (storm tides comprise

the su m of storm su rge an d ast ronomical tides).

Andr ew tra versed sout h Florida a nd en tered t he Gulf of Mexico just 4 hours a fter impacting t he

east coast of Florida. After weaken ing to a cat egory 3 over lan d, the st orm quickly reinten sified

to a cat egory 4 as it moved across the gulf. Pr ior t o its lan dfall in Louisian a a t 4:30 AM EDT

on August 26, Andr ew a gain weak ened to a category 3. Its ma ximu m susta ined winds in

Louisiana were estima ted at 120 mph with higher gusts.

The devasta tion left in Andrews wake over sout h Florida was imm ense. Total dama ge

estim at es of a bout $25 billion cann ot convey th e profound impa ct of th e storm. According to

insur an ce indust ry leader s, the t otal economic impa ct of Andrew will rea ch $35-40 billion by

1995. Moreover, the fabr ic of orga nized society was sh redded in sout h Da de Coun ty, Florida.

A tota l of 126,000 houses were dest royed or da ma ged an d 9,000 mobile homes were dest royed.

Andr ew left at lea st 1 60,000 people homeless in Dade Coun ty alone. Per ha ps years will be

requ ired to rebu ild the original infra str uctu re. The mu nicipal electr ic power grid in Homest ead

an d Florida City was dest royed. Ban king, and t her efore m uch of societys ability to fun ction,

cam e to a ha lt. Businesses were u na ble to reopen because their employees were homeless and

str uggling to shelter , cloth e, and feed them selves an d th eir fam ilies. A tota l of 86,000 people

lost th eir jobs. The Na tional Guar d provided ten t cities an d the essent ials to live, but m an y

chose to rem ain in wha t wa s left of their h omes for fear of looting.

The damage from Andrew across Louisiana was overshadowed by what occurred in south

Florida, but t he storm st ill had a profound effect. Dam ages from Andrew in Louisian a a re

est ima t ed to exceed $1 billion. Some sma ll businesses were lost an d ma ny suffered some

dam age. Much of th e estima ted losses were insur ed: about 3,300 single fam ily, mu ltifam ily,

an d mobile homes were destroyed. Over 18,000 un its received some dam age. As in sout h

Florida, the Na tional Gua rd quickly took cont rol, protecting the h ar dest h it ar eas from looting.

The storm s effect on L ouisia na public ut ilities was minima l. Quick action by local an d

Louisiana state officials promoted both a rapid response to the disaster and immediate

laun ching of a coordin at ed r ecovery effort .

Despite th e severe physical dam ages an d crippling monetar y losses, hu ma n casua lties weresurpr isingly few. In F lorida, 15 death s were directly attr ibuted to th e storm, with an other 29

fata lities in directly related. Those indirect fat alities were cau sed by electr ocut ions, clean up

accident s, fires, an d oth er incidents associat ed with r ecovery. In Louisia n a , 8 direct an d 9

indirect fat alities occur red. In direct fata lity tota ls depend on the br oadn ess of definit ion a nd

var y grea tly. For exam ple, one ma jor newspa per reported 85 indirect sout h Florida fat alities.

Those num bers include persons killed in motor vehicle accidents wh ere a stop sign wa s down du e

to Andr ew. The nu mber of indirect fata lities the disast er sur vey tea m uses (29 in sout h Florida


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xvi

and 9 in Louisiana) are those for which the county medical examiner or parish coroner

determ ined the st orm to be a cont ributing factor.

Even before t he P resident ial Declar at ion of Disaster , NOAA/NWS assem bled a Disa ster Sur vey

Team. The DST was responsible for a ssessing th e perform an ce of NOAA and th e ha zards

comm unity prior t o and dur ing the h urr ican e. The ha zards comm un ity consists of all Federal,

stat e, and local governmen ta l entities, as well as t he m ass m edia an d volunteer organ izat ions,

involved in th e distr ibution a nd dissemin at ion of weat her inform at ion for t he pr otection of life

an d property. Following the a ssessmen t, th e DST was responsible for providing any necessar y

recomm endat ions for improvement s.

The DST found that NOAA performed exceptionally well both prior to and during Hurricane

Andr ew. The hur rican e forecast tr ack error was 30 percent less tha n avera ge. Lead times on

hur rican e wat ches and warn ings were 3 to 6 hours better th an a verage. Hur rican e wat ches

were issued with 36 hours of lead time in south Florida a nd 43 hours in Louisiana. Hur rican e

warnings were issued with 21 hours lead time in south Florida and 36 hours in Louisiana.

Throughout the event, NWS personnel, despite enormous personal hardship, supplied timely,

high qu ality inform at ion t o the pu blic via NOAA Weat her Radio (NWR), NOAA Weat her WireService (NWWS), direct links with emergency ma na gement, a nd t he m ass m edia. To assur e th is

flow of vita l informa tion, cont ingency plan s were a ctivat ed for ba ckup of th e NHC a nd for t he

Weath er S ervice F orecast Office (WSFO) at Miami should th ey ha ve become un able to fun ction.

Those plans were not need ed for t he NH C, but WSFO Atlan ta an d Weath er Service Offices

(WSO) at Tam pa Ba y an d West Pa lm Beach provided forecasting issuan ce an d backup war nings,

respectively, for WSFO Miam i.

Sta te, county/par ish, and local emer gency ma na gemen t a gencies, working in concert with la w

enforcemen t a nd ba sed on informa tion supplied by th e NWS, coordinat ed some of th e largest

evacua tions in Un ited States h istory. In south Florida, as well as Louisian a, litera lly hun dreds

of thousa nds of people left t heir homes.

The DST found that the collection and dissemination of information, through appropriate

warn ings an d stat ement s, need improvement. In par ticular, hur rican e local stat ement s (HLS)

need to be shorten ed an d reorgan ized to provide more timely and specific inform at ion per ta ining

to the local ar ea. The DST found a lso tha t WSOs and WSF Os need to address storm-scale

events occurring within hurricanes by using appropriate severe weather warnings and

sta tem ent s, includin g torna do war nings. Additiona lly, Andrew re-emph asized th e need for

improvement in h urr ican e int ensity forecasting. Fina lly, the DST found th at wind, not storm

sur ge, was t he ma jor cause of direct dea th s in Andr ew. Still, th ese sta tistics need to be kept in

persp ective: 12 of th e 15 death s directly at tr ibuted t o Andr ew in F lorida wer e cau sed by wind

as compared to the potential for hundreds of fatalities that could have occurred from storm

sur ge. The rea lity is tha t eva cua tion from wind would involve far too ma ny people to beaccomplished; alternat ive sh elter m ay be necessar y.


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SUMMARY OF

FIND INGS AND RECOMMENDATIONS

PART I

Chap te r I.B

Finding I.B.1: The NHC is cha rged with a na tional focus on hu rrican e readiness, but it

domina tes the NWS hur rican e preparedn ess program in south F lorida.

Recomm enda tion I .B.1: The NWS should sta ff WSFO Miami with a Wa rn ing Coordina tion

Meteorologist (WCM) as soon a s possible to enha nce th e WSFOs prepa redn ess/haza rd

awareness program .

Find ing I.B.2: This was th e first tim e tha t th e NHC (an d th e collocat ed WSFO Miam i) facility

ha d been directly affected by a ma jor hu rr ican e. The impa ct of Andrew proved th e vulnera bility

of NHC t o the effects of extrem e wind.

Recomm enda tion I .B.2: Bett er protected, self-cont ained facilities sh ould be provided to th e

NH C an d all NWS coasta l offices. This is even m ore critical to Na tional Cent ers, such a s NHC,

for wh ich full backup pr ocedures a re extr emely difficult to implemen t.

Find ing I.B.3: Hu rr ican e Andr ew was cha ra cterized by devast at ing effects of str ong inland

winds in a ddition t o powerful storm sur ges. The devast at ion th at even tu ally occur red over sout h

Florida heightened the awareness in other vulnerable areas to the significant inland winddam age which can a ccompa ny a h ur rican e.

Recommendation I .B.3: The NWS should provide technical assista nce for a much more

concerted prepa redness an d awa reness effort by stat e an d local emergency ma na gement a nd

such oth er cognizan t organ izat ions a s sta te coast al zone m an agement agencies in a reas of high

vulnerability.

Find ing I.B.4: Since the lead t ime for evacuation may be no more th an 24 hour s, it ma y not

be pra ctical or even possible to evacua te a ll inland r esidents in th e pat h of a h ur rican e eyewall.

Recommendation I .B.4: The NWS should work with F EMA, sta te, an d local emer gency

planners in exploring the potential of developing a "refuge of last resort" methodology, as

appr opriat e, for occasions when critical satu ra tion points a re r eached in t he flow of evacua tion

traffic.


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xviii

Chap te r I.C

Find ing I.C.1: The deta iling of two hur rican e specialists to the Na tional Meteorological Cent er

(NMC) is not sufficient to provide adequ at e continu ous backup t o NH C opera tions.

Recommendation I .C.1: The NWS should adopt a plan t ha t would increase the num ber offorecasters capable of acting as hurricane specialists during an emergency brought on by a

hur rican e thr eaten ing NHC. There must be adequa te sta ffing at both NHC and th e backup site.

One pla n would be to provide hu rr ican e forecast tr ainin g to a select group of forecast ers, possibly

from N MC, who could fly to NH C as r eplacement s for hur ricane specialists dispat ched t o staff

the backup center .

Find ing I.C.2: When NH C sta ff is drawn down t o implement t he backup a t NMC, insu fficient

sta ff rem ain s at NH C to han dle advisories of mu ltiple tropical cyclones pr operly.

Recomm enda tion I .C.2: See Recommen dat ion I.C.1.

Finding I.C.3 : Fa cilities for int eracting with th e media ar e very limited at NMC.

Recomm enda tion I .C.3: The NMC should form ula te a plan for ha ndling the extensive

intera ctions with t he media tha t ar e required when a hu rrican e is threa tening the United Sta tes

coast line. Since NMC is th e logical site for th e backup forecast cent er, plans sh ould be ma de to

accommodat e the lar ge num ber of media per sonnel who will descend u pon the ba cku p cent er,

especially if it is requ ired to ta ke over t he pr ima ry forecast mission.

Chap te r I.D

Find ing I.D.1: NHC watch and wa rning lead times during Hurr ican e Andrew were longer th an

average for lan dfalling hurr ican es. Tha t extr a ma rgin of safety was at least part ially

responsible for a llowing h un dreds of th ousa nds of people to evacuat e sa fely from sout h Florida.

Recomm endation I .D.1: NOAA an d the NWS should work towar d increa sing watch/warn ing

lead tim es by supporting effort s to enh an ce our u nder sta nding of tr opical system s, improving

numerical models, providing greater data availability to feed the models, and enhancing

opera tiona l forecast m eth odologies. A significan t st ep in th is direction would be th e collocat ion

of th e Environm ent al Resear ch Laborat orys Hur ricane Resea rch Division (HRD) with NH C to

allow for the syner gism of resea rch a nd opera tions.

Find ing I.D.2: HLSs from WSO/WSFOs t end to be too length y, too infrequ ent , tend to reitera te

NHC advisories too much, and tend not to include enough specific information about local

conditions.


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Recomm endation I .D.2: The NWS should explore options to mak e HLSs m ore effective. This

should include use of the "Short Term Forecast" concept and its relationship to HLSs and

hur rican e advisories. Fu rth ermore, coast al offices should re-evaluat e th e m an ner in which dat a

ar e collected an d used to crea te H LS products. Em pha sis should be ma de on use of on-sta tion

software, emergency management information, and remote sensing data to create a highly

specific, cur ren t product.

Chap te r I.E

Find ing I.E.1: Concern wa s expressed by two emer gency ma na gers over the tone set by NHC

on Friday afternoon when a "Have a good weekend...tune back in on Sunday or Monday"

messa ge was given to emer gency ma na gement . Some officials felt tha t messa ge could ha ve

promoted a less-than-serious attitude and that it could have caused them not to pay close

at tent ion t o storm inform ation during th e weekend.

Recomm enda tion I .E.1: Alth ough NHC is extr emely concer ned about h ow inform at ion is

presented, care m ust cont inue to be exercised not to send un intended m essages.

Find ing I.E.2: Many coasta l emergency ma na gers do not un dersta nd th e scient ific reasoning

involved in designat ing hu rrican e watch and wa rning ar eas. They want to evacuate either a ll

or n one of their coast al sur ge vulnera ble ar ea r at her t han par ts of coun ties.

Recomm enda tion I .E.2: There needs to be better dialogue between NHC an d emergency

ma na gement involving the designa tion of hur rican e wat ch a nd wa rning a reas. Conference calls

following or preceding a watch or warning issuance always should contain a thorough

explana tion for t he choice of the en d point s of the a rea s. NHC a lso should explore t he feasibility

of including th is informa tion in th e tropica l cyclone discussions. Cours es offered at NH C foremergency ma na gers should include a segment on t he subject of designat ing watch an d war ning

areas .

Find ing I.E.3: One critical a spect of hu rr ican e forecast ing & th e inten sificat ion of storms & lags

far behind th e balan ce of th e science. SHI FOR, th e compu ter m odel used to forecast h ur ricane

inten sificat ion, is old an d ineffective. It d oes a poor job of han dling ra pid inten sificat ion.

Recomm enda tion I .E.3: NHC, N MC, an d HRD should redouble th eir efforts t o develop models

an d operat iona l techniques t o forecast tr opical cyclone int ensity cha nges m ore effectively. In

tu rn , NOAA should support r esear ch efforts at un derst an ding and predicting cyclone inten sity

changes.

Find ing I.E.4: Some emergency mana gers could have made greater use of hu rr ican e str ike

probabilities and per sonal compu ter (PC) softwa re in t heir decision-ma king process.

Recomm enda tion I .E.4: Em ergency man agement needs to use all the t ools available to them

to provide information for their decision-making processes, including PC-based software


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specifically designed for th at pur pose. The N WS sh ould work with F EMA to support m ore

workshops for coas ta l emer gency ma na gers. This should include instr uctions on how t o use

th ese t ools effectively.

Find ing I.E.5: As a result of increased an xiety caused by Hurr ican e Andr ew, ma ny sout h

Florida residents indicat ed they would evacua te for futu re ma jor hu rr ican es. In deed, if th is was

the case, evacuation times for a category 4 or 5 hurricane striking the Florida Keys would

increase from th e pre-Andr ew level of 37 hour s to 70-80 hours, depen ding on th e percenta ge of

residents evacuating.

Recomm enda tion I .E.5: NWS a nd F EMA should work in concert to develop response options

as outlined in Recomm endat ions I.B.4 an d I.F.2.

Find ing I.E.6: The link between th e NWS, emergency ma na gement, and t he broadcast m edia

is critical to an y commu nity war ning system. A pa rt ne r ship developed to coordina te NHC

information through a broadcast "pool" enabled a large number of media outlets to receivebroadcast footage from NH C without crowding th e facility an d compr omising th e opera tional

setting.

Recomm enda tion I .E.6: NWS should support developmen t of similar br oadcast pools a t local

offices along th e hu rr ican e-prone coast s, as well as a t N MC, should backup for N HC be r equired.

Find ing I.E.7: Television met eorologists were inst ru men ta l in en coura ging evacua tion from

the t hrea tened a rea s. Many of the t elevision broadcasts were simulcast on AM and FM r adio.

This was particularly useful since many residents received lifesaving advice through their

batt ery-operat ed ra dios when television t ra nsm itters were knocked off the a ir.

Recomm enda tion I .E.7: NWS offices along hur ricane-thr eat ened area s shou ld continu e to

encourage proactive, weather-conscious media who will provide that essential link with the

public to convey lifesaving information.

Find ing I.E.8: Effort s of th e NWS, in conjun ction with sta te a nd local emer gency ma na gemen t

an d the n ews media, resulted in clear an d motivat ing messages to the genera l public. Those

messa ges resulted in a super b public response, except for some r esidents of Miam i Beach, an d

ma y have saved coun tless lives.

Recomm enda tion I .E.8: NHC a nd WSFO Miam i should work with t he local media to tar getthose populations in Miami Beach where the response was deficient.


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Chap te r I.F

Find ing I.F.1: NHC an d NWS representa tives, when ma king a case for refuges of last resort ,

may have contributed unintentionally to the problem of public resistance to evacuation by

stressing th e dan ger of being caught tr ying to evacua te.

Recommendation I .F.1: NWS and NHC representa tives need to stress to the public th e

importa nce of referring to appr opriate sta te an d local emer gency ma na gement directives about

evacua tion orders.

Find ing I.F.2: If residents of the ha rd hit Na ra nja Lakes ar ea ha d not evacua ted becau se of

the storm su rge th reat , more death s likely would ha ve resulted from th e effects of wind.

Recomm endation I .F.2: Since in m an y cases evacua tion is not a viable option, the NWS an d

the Federal Emergency Management Agency (FEMA) should work together to encourage the

concept of engineered in-residence shelters to protect from severe wind without invoking

evacuation procedures.

Find ing I.F.3: Man y residents whose houses began to disintegr at e during th e storm followed

"tornado safety rules" and went to the interior part of their house away from windows and

out side walls.

Recomm enda tion I .F.3: NWS and emergency ma na gement agencies should make "torna do

safety ru les" a st an dar d componen t of hu rr ican e awa ren ess efforts, especially for st rong storm s.

The pu blic also should be better educat ed about t he kinds of constr uction a nd building designs

which a re m ost vulnera ble in str ong hur rican es.

Chap te r I.G

Finding I.G.1: Sma ll err ors in t h e tr ack forecast pr oduced by th e Aviation Model were

impr essive for th is sma ll samp le of forecast s.

Recomm enda tion I .G.1: NOAA should continu e to support development of such m odels. In

order to use th ese models most effectively, meth ods need to be explored t o gat her bett er da ta in

an d aroun d tropica l cyclones. The Omega dropwinsonde experiment sh ould be conducted to

evaluate the potential of this capability.

Find ing I.G.2: The storm su rge impacted a r elatively sma ll ar ea of coastline, but t he SLOSH

model accur at ely depicted t he su rge in south Florida.

Recomm enda tion I .G.2: Refinem ent s to th e SLOSH model should cont inue. Also, tr ainin g

of NWS offices and em ergency ma na gers in its use should be empha sized. The SLOSH model

should be validated in coopera tion with t he NOS /Office of Ocean an d Ea rt h S ciences (OES) and


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xxii

oth ers to furt her cont inued improvements in th e model. A greater effort should be made to

docum ent its physics an d the validat ion efforts th at justify its use. NOS should assist with su ch

a docum enta tion.

Find ing I.G.3: On-sta tion comput ers at WSOs and WSFOs are inadequa te to run storm surge

an d applicat ions pr ogram s.

Recomm endation I .G.3: Coasta l NWS offices should be provided sufficient P C ha rdwa re a nd

softwa re t o display SLOSH MEOW (Maximu m E nvelop of Wat er) data as well as t o ru n su rge

applications an d hu rr ican e decision-ma king program s. The Advan ced Weat her Int era ctive

Processing System (AWIPS), under development for future NWS Weather Forecast Offices,

should be able to support th ese progra ms.

Chap te r I.H

Find ing I.H.1: Despite th e extensive comm ercial m edia covera ge of Andr ew, both th e NWWS

an d NWR wer e well received and were u tilized a s official a nd timely sources of NWS informa tion

regarding the event.

Recomm enda tion I .H.1: The NWS should cont inue str ong encour agem ent of th e widesprea d

us e of NWWS and NWR a s officia l sour ces of NWS inform a tion. High pr iorit y should be placed

on plan ned NWR upgrades an d more wind-resista nt tra nsmitt ers, feat uring voice synthesis, to

impr ove the qua lity an d efficiency of NWR dissemina tion dur ing m ajor weath er events. The

NWS should develop partnerships with FEMA and other organizations to increase NWR

covera ge as well as th e broadcast ing of critical pre- an d post-event in form at ion.

Find ing I.H.2: NHC m ad e effective use of th e Florida Na tional Warn ing System (NAWAS)

circuit to communicate with Florida emergency managers and Florida WSOs on importanthur rican e inform at ion.

Recomm enda tion I .H.2: FE MA, NWS, and sta te emergency ma na gement offices should

develop procedur es to use t he n at iona l NAWAS circuit for m ultista te conference calls so th a t

NHC can brief all appropriate emergency management officials on the network during a

hurricane threat .

Finding I.H.3: Excessive heat build-up cont ributed to the failur e of th e IBM ma infra me

compu ter a t th e NHC during th e hur rican e. This was the m ost serious comm unicat ions failure

at NHC becau se of th e IBMs role in dr iving t he McIDAS VDUC, a principal sour ce of int era ctivesat ellite dat a for t he NH C sta ff. In a ddition, oth er importa nt circuits failed which depended on

the IBM.

Recomm enda tion I .H.3: The NWS should inst all a st an d-alone air-conditioning system for

th e NHC independent of leased comm ercial facilities. This would great ly minim ize th e hea ting

problem of critical communications and computer equipment.


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xxiii

Chap te r I.I

Finding I.I.1: Sa tellite ima gery is th e only sour ce of informa tion over dat a-spar se ocean s,

except for sh ips which gener ally avoid rough weat her .

Recomm endation I .I .1: NOAA mu st ma ke every effort t o ensure th at th e GOES-Next(Geostationary Operational Environmental Satellite-Next Generation Satellite) program

rem ains on schedu le. Mean while, No-GOES plan s need to be test ed routinely.

Find ing I.I.2: Aircra ft reconn aissa nce is a necessar y an d vita l tool for mea sur ing storm

intensity, for defining wind fields, and for calibrating satellite estimates of storm intensity.

However, the current airframes are aging and provide limited range and performance

characteristics.

Recomm endation I .I .2: Aircraft reconn aissa nce of tr opical cyclones m ust cont inue. In order

to provide high quality data on the storm and its environment, NOAA should explore cost-

effective options on futu re sensors an d airfram es. This mu st be done now if we are t o ma keeffective use of next genera tion m odels for t ropical cyclone in ten sity an d t ra ck forecast ing.

Find ing I.I.3: The precision, r an ge, an d r efinemen t offered by th e WSR-88D allowed for pr ecise

location not only of the eye but also, long before landfall, of stronger elements in the spiral

ban ds. The a bility of th e WSO at Melbour ne to observe an d report on th ese sma ll but significan t

featu res ena bled th em t o allay public fear s about a potent ially approaching hurr ican e.

Recomm endation I .I .3: Efforts by t he NWS, th e Feder al Aviation Administ ra tion (FAA), an d

th e Depart men t of Defense (DOD) to deploy th e WSR-88D nat ionwide must cont inu e. In

addit ion, NOAA needs t o assu re sta ffing of its NWS Doppler r ada r equ ipped offices with properlytra ined personnel in order t o take best a dvanta ge of this powerful dat a source.

Find ing I.I.4: Wind observations ar e taken at varying heights an d with different sa mpling

stra tegies, mak ing the determ ination of winds dur ing a severe storm difficult t o assess.

Recomm endation I .I .4: T he Office of th e Fed era l Coordina tor for Meteorology should contin ue

to work with the various Federal agencies to ensure that wind observation adjustments are

stan dar dized for height a nd sa mpling interval variat ions t o ensure consistency of data .

Fin din g I.I.5: Man y wind observation sites failed not becau se of a failure of th e instr um ent butbecau se of the m an ner in which the support ha rdwar e was constr ucted and a ssembled.

Recommendation I .I .5: The NWS and FAA need to invent ory their F420 a nem omet er

installations in hur rican e-th rea tened a reas. The NWS and F AA should consider retrofitting

suspect F420 sites with a locking cross arm prior t o th e 1994 hur rican e season. Fu rt herm ore,

th e NWS Automa tic Surface Observing System (ASOS) progra m office should investigat e th e

potent ial for failures in t he ASOS wind ma st a nd sen sors du ring high wind episodes.


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Find ing I.I.6: Valua ble wind and pressure observations were lost when t he dat a-gathering

system s wer e powered down or r emoved before Andrews lan dfall.

Recommendation I.I.6: Agencies with m eteorological dat a-gat her ing equipmen t in the pat h

of a hurricane should be encouraged to continue the data collection process throughout the

event.

P ART II

Chap te r II.B

Find ing II.B.1: Ther e is an insufficient supply of safety an d prepa redn ess ma ter ials in support

of NWS field offices, local emergency preparedness officials, and the public.

Recommendation II .B.1: NOAA an d the Depart men t of Comm erce should increa se their

support for developing, printing, and distributing high qua lity prepa redness a nd a wa ren ess

ma ter ials. Pr esent coopera tive effort s with oth er agen cies an d the pr ivate sector to develop an d

distribute awar eness and prepa redness ma terials should be increased.

Finding II.B.2: The local print media is more reactive in comm un ity prepar edness tha n

proactive. Historically, in sout h Louisian a, the print m edia ha s not actively par ticipat ed in

preseason hurr ican e preparedness effort s, such as awaren ess cam paigns. On the other h an d,

dur ing the 72 h ours prior to Andr ew, they were extrem ely effective in providing th eir rea dersh ip

with deta iled prepar edness inform at ion.

Recomm enda tion II.B.2: NWS offices in sout h Louisian a need t o develop str onger cooperat ive

relationships with the pr int media to enha nce their involvement in th e hazar ds awar eness andmitigation pr ogram .

Find ing II.B.3: Local emer gency ma na gers in sout h Louisian a were very proactive, ta king the

early initiative in dea ling with H ur rican e Andrew.

Recommendation II .B.3: The NWS m ust continu e working closely with local emergency

ma na gers to ensure t ha t together th ey promote a un ified awareness program which elicits the

desired pu blic response.


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Chap te r II.D

Find ing II.D.1: User s of NWS products would like more specific, techn ica l informa tion to ass ist

them in their decision-making process.

Recomm endation II.D.1: The NHC should work with users t o define wha t additiona linform at ion is required a nd t o develop a mean s of comm unicating th at inform at ion to them .

Find ing II.D.2: Hu rr ican e local stat emen ts were t oo closely tied to th e issua nce of hu rr ican e

advisories. As a r esult, th e disseminat ion of critical inform at ion concerning t orn adic event s was

delayed.

Recomm endation II.D.2: The issua nce of hu rr ican e local sta tem ent s should be event dr iven,

ra ther tha n t ied exclusively to rout ine NHC issua nces.

Find ing II.D.3: Dur ing the pea k period of torn ado activity, several reports of torn adoes werehighlighted in t he H LSs. One of th ese report s proved to be erroneous. Rath er tha n issue a

corr ected HLS, the WSF O issued a special weat her st at ement to acknowledge th e error. This

could have caused confusion and loss of precious time for users during a period of rapidly

cha nging events.

Recomm endation II.D.3: NWS field offices should follow est ablished NWS forma ts for issuin g

corrections.

Chap te r II.E

Find ing II.E.1: FE MA/NWS-sponsored Hu rr ican e Response a nd Decision-ma king Worksh ops

ar e condu cted only a few times each year . These workshops ar e incapa ble of rea ching su fficient

nu mber s of emer gency officials. This limits t he effectiveness of th e hur rican e prepa re dn ess

program.

Recommendation II .E.1: FE MA an d the NWS should increase the num ber of an nua l

hur rican e workshops to tr ain coasta l emer gency ma na gement officials.

Find ing II.E.2: Due t o the close proximit y of th e WSFO, an agr eemen t with th e city allows for

a ded icat ed m eteorologist to be dispatched from t he WSF O to the local Emer gency Opera tions

Center (EOC) during hu rr ican e events which may th reat en th e city.

Rec omm en dation II.E.2: Appropriat e NWS sta ff should be dedicat ed to work with emer gency

ma na gement officials during ma jor h azar dous weat her event s.


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Find ing II.E.3: Form al evacua tion cleara nce stu dies for south west Louisian a ha ve yet to be

completed.

Recommendation II.E.3: FE MA an d the USACE, with N WS support , should accelerat e their

effort s to complete evacuat ion st udies for a ll hu rr ican e-prone coast al ar eas.

Find ing II.E.4: In general, coast al resident s kn ow that t hey have a potent ial storm surge

problem. However, in some h ighly populated ar eas, such a s Greater New Orleans, th ere ar e

preliminary evacuation studies but no proven orderly plan for the safe and timely evacuation

of th e entire metr opolita n a rea . Fu rt herm ore, the scope of th ese studies does not a ddress

regiona l complications which can compr omise order ly evacua tion.

Recommendation II.E.4: FE MA, in concert with th e NWS, should ensu re t he completion of

local evacuation studies an d integra te t hem into a compr ehensive regiona l evacua tion plan .

Find ing II.E.5: The emergency mana gement comm unity of sout heast Louisian a felt stronglythat the fear of looting was partially responsible for a smaller than expected number of

evacuees.

Recommendation II.E.5: Local governm ent s, with NWS an d FE MA assist an ce, need to

educate r esidents to alleviate t hese ina ccur at e perceptions.

Finding II.E.6: Ther e were a few insta nces wher e one local television sta tion present ed

forecast tr ack scena rios th at conflicted with official NHC forecast s. Tha t cau sed some problems

for local parish and NWS officials.

Recommendation II.E.6: The local NWS offices in Louisian a s hould ma ke a ren ewed effort

to impress upon t he loca l media t ha t pr oviding consisten t inform at ion t o th e public is critical

during em ergency situat ions.

Chap te r II.F

Find ing II.F.1: Many south east Louisian a residents did not un derst an d the full extent of

danger from st orm sur ge.

Recomm endation II.F.1: The NWS n eeds to work m ore closely with F EMA, as well as sta te

and local officials, to develop more effective preparedness information about storm surge.Presentations tailored to local areas could provide information about situations to which

residents could better relate.

Finding II.F.2: Some south Louisian a residents inter viewed comm ented tha t t hey had

evacuated highly vulnerable areas only to find themselves threatened by other hurricane

dangers.


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Recomm endation II.F.2: The NWS, in concert with local em ergency ma na gemen t officials,

should ensure tha t evacua tion stu dies are up to dat e and accura te. Given widespread

distribution, th e resu lts of these st udies can direct the public to appropriate shelter.


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Find ing II.F.3: Despite the effort s of th e NWS an d stat e an d local emer gency ma na gers, not

all residents h eeded the various evacuat ion r equests even though t heir lives ma y ha ve been in

jeopar dy had t he st orm ma de landfall fur th er east along th e Louisiana coast.

Recomm endation II.F.3: The NWS and F EMA need to increase their efforts to educat e an d

tra in the public. Ea ch a gency needs t o consider expan ding th eir tr aining capa bilities to

overcome t he pu blics denial of th e th rea t from hu rr ican es.

Find ing II.F.4: Some residents of Great er New Orleans who evacuat ed and lat er retu rned to

th eir homes felt t ha t local officials overrea cted in th eir evacua tion recomm enda tions, especially

since Andrew m ade lan dfall fur ther west th an projected.

Recomm endation II.F.4: The NWS needs to work closely with th e emer gency ma na gemen t

comm un ity in convincing th is most skept ical segment of th e populat ion t ha t t he a dvan ta ges of

evacua ting far outweigh t he disadvan ta ges of remaining in place.

Chap te r II.G

Finding II.G.1: WSF O Slidell, being collocat ed with th e Lower Mississippi River Forecast

Center (LMRFC), had access to RFC PCs and was able to run SLOSH MEOW and other

hurricane decision-making applications.

Recommendation II.G.1: See Recommen dat ion I.G.3.

Chap te r II.H

Find ing II.H.1: The Un iversal Gener ic Codes (UGC) were incorr ectly ent ered in severa l of the

products dissem ina ted by south Louisian a offices.

Recommendation II.H.1: NWS offices sh ould perform m ore on-th e-spot qua lity cont rol of

products prior to th eir public release. The u se of softwa re, such a s version 6.0 of SRWar n, would

help eliminat e ma ny of these er rors.

Find ing II.H.2: Curr ently, not all coast al WSOs have access to the hu rr ican e hotline.

Recomm enda tion II.H.2: NOAA needs to expan d the hu rr ican e hotline t o all coasta l WSOs

in hurricane vulnerable areas.

Find ing II.H.3: The u se of Army MARS (Milita ry Affiliat e Radio System) within th e Louisian a

emer gency comm un icat ions syst em wa s very successful.


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Recommendation II.H.3: The NWS and F EMA need to coordina te with Army MARS to

ensur e th at these capabilities can be extended t o other locat ions.

Find ing II.H.4: The Sta te of Louisian a, Division of Em ergency Man agem ent , cur ren tly does

not ha ve a fully aut oma ted inform at ion r edistribution system .

Recomm enda tion II.H.4: The NWS an d FE MA should encoura ge the Stat e of Louisian a to

explore options for providing a fully automated communications system to law enforcement

agencies and local emer gency opera ting center s. Once in place, th e NWS should ar ra nge to link

with th at system a llowing two-way comm un icat ion of critical war ning inform at ion bet ween th e

NWS and the emergency ma na gement comm un ity.

Chap te r II.I

Finding II.I.1: The U.S. Coast Gua rd (USCG) ha s decided to remove all lar ge navigat iona l

buoys an d replace th em with other , smaller types of buoys. The r eplacement buoys are too sma ll

to be fitted with m eteorological instr um ent s. Loss of th e cur ren t buoys, in th e nea r futu re, will

mea n t he loss of hour ly data from st at ions a long th e Atlan tic and Gu lf of Mexico coast s.

Recommendation II.I.1: The NWS, th rough its Na tiona l Dat a Buoy Center , should ensure

tha t sufficient capabilities a re present to ma intain hourly observations along t he Atlant ic an d

Gulf of Mexico coastal waters.

Fin din g II.I.2: The implement at ion of service maint enan ce fees has resulted in th e removal

of met eorological equipmen t from gulf oil plat forms, a nd a significan t loss of data ha s occur red.

Recommendation II.I.2: NOAA mu st r eview its position on cha rging oil platform s a service

fee to maintain meteorological equipment.

Fin din g II.I.3: Alth ough Andr ew did not move into WSO Houston s effective Doppler range,

the WSR-88D radar did provide extremely detailed reflectivity data on the storm.

Recommendation II.I.3: See Recommen dat ion I.I.3.


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This tra nquil scene was ta ken a t Sewell Pa rk in F lorida locat ed on t he m out h

of the Miam i River on a norma l day.

This is Sewell Park just after da ybreak on August 24 & water is still elevated.


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Aerial photo of the marina "Gables by the Sea"

locat ed near Gables Esta tes, Florida. Num erous

boats were forced ashore by the 9- to 16-ft storm

surge.


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HUR RICANE ANDREW:

THE EVENT AND ITS IMP ACT

The intense winds accompa nying Hurr ican e Andrew caused ma ssive dam age in southern Dade

Count y and rendered it th e costliest st orm in United Sta tes history. The mind-num bing

statistics of Andrew include 126,000 single family houses destroyed or damaged and 9,000

m obile homes destr oyed. Officials order ed ent ire complexes bulldozed becau se th ere were n o

salvagea ble stru ctur es. Mobile home park s were cleared to mak e room for tempora ry housing.

Andrew left 160,000 people homeless in Da de Count y alone. A tota l of 86,000 resident s lost jobs,

ma ny perman ently. Still, Florida was spared from an even larger disaster . Andrew was a

compa ct, fast -moving, relat ively dry storm. Ha d it been lar ger, slower, or carr ied more ra in, its

consequen ces would have been even more devast at ing. Fu rth er, and m ore significan tly,

Andr ews tra ckminimized th e dama ge to Dade Coun ty. Ha d the eye of the storm crossed the

coast just 10 miles fur ther to the north, it would ha ve devasta ted downt own Miami, probably

causing grea ter loss of life an d ten s of billions of dollars m ore in pr opert y dam age. Andr ew

would have affected not only south Florida but the global economy since Miami is a veryprominent world banking center .

Andr ew was the th ird strongest lan dfalling hur rican e in th e United States th is centu ry. The

estimat ed centr al pressure at lan dfall in Florida wa s 922 millibar s (mb). The storm wa s

classified at the upper threshold of category 4 on the Saffir-Simpson intensity scale (see

appen dix G). After ra king Da de Count y, Andrew cont inued ra pidly westwa rd across south

Florida an d rem ain ed an inten se storm as it tra versed the Gulf of Mexico. Coincident with its

land fall in Louisian a, it cau sed fur th er significan t da ma ge. Although lives were lost both in

Florida and Louisiana, the number of deaths was small considering the magnitude of

destr uction to propert y. Tha t low num ber of fata lities was du e par tia lly to accur at e forecas ts

an d effective prepar at ions a nd p a rt ially to the limited effect of storm su rge. In F lorida, 15

deaths are directly attributable to Andrew (29 indirect, including post-event electrocutions,

cleanup a ccident s, heart at ta cks, and the like). In Louisiana, 8 fata lities are directly relat ed to

the storm a nd an oth er 9 indirect.

In Louisiana, preliminary data for the 36-parish disaster area indicated that 3,301 single,

multifamily, and mobile homes were destroyed, and 18,247 units received major or minor

dam ages. Dat a compiled by a consort ium of sta te agen cies an d groups with specific

responsibilities in agriculture indicated that estimated agricultural losses would exceed $288

million. Su gar can e yield losses were estim at ed a t $128.4 million, cott on losses a t $68.2 million,

an d forest ry-related losses at $38.6 million. The consort ium a lso estima ted losses of $13.2

million for t he s oybean cr op, $12.7 million for corn , an d $9.1 million for r ice.

History of the Storm

Andrew form ed from a tr opical wave t ha t m oved off th e African coast on August 14, 1992. The

"best t ra ck" an alysis of th e storm s tr ack is shown in figure 1. ("Best tr ack" is a term used by

th e NHC t o describe th e closest post-event a pproximat ion possible on the t ra ck of a


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Figure 1 & Best t ra ck positions for Hu rr ican e Andrew


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tr opical system, based on sa tellite imagery, surface and sh ip observations, a nd a ny other dat a

ava ilable.) Since th e system wa s still out side of air r econna issance ra nge, sat ellite imager y was

used exclusively to monitor the m ovemen t a nd str uctur al cha nges to the developing system. By

2 PM EDT on August 16, the system had developed spiral cloud bands with wind speed

estimat ed at 30 knots (34 miles per hour [mph]). The best tra ck ana lysis indicat es tha t th e

storm becam e a tr opical depression at about th at t ime.

On August 17, Andr ew was classified as a t ropical storm . It m oved along a west-north wester ly

tra ck un til August 22. The storm form ed an d intensified in an environment of weak ea sterly

vertical wind shea r. Lar ge-scale processes tha t lea d t o tr opical cyclogenesis are not well

understood, but both observational and numerical modelling studies consistently show that

cyclones can form an d int ensify readily in conditions of weak vert ical sh ear , or sometimes in

regions of modera te east erly shear . However, significan t wester ly shea r over th e top of a

tr opical cyclone is us ua lly un favora ble for inten sificat ion or even m aint ena nce of th e storm .

Dur ing Augu st 19-20, Andr ew moved int o a r egion with st rong upper -level south wester ly winds

associated with a n upper-level low pr essure system situa ted northwest of the storm. The

resu lting vertical shea r is the pr obable cau se of th e observed filling of the centr al pressu re t oabout 1015 mb. During th is period, aircra ft reconna issan ce found th at the st orm circulation at

lower levels was poorly organized, and satellite imagery showed only intermittent deep

convection in the core region.

Dur ing August 21, the upper level low moved away from t he st orm, an d Andr ew was once aga in

in an environm ent with vertical shears favorin g inten sificat ion. It a lso tu rned west and

accelera ted to about 18 m ph a s high pressure n orth of the storm intensified, strength ening the

east erly flow with in which Andrew was embedde d. The storm t hen followed an alm ost due

westward tr ack unt il it crossed Florida. Andrew ra pidly deepened an d reached hurr ican e

inten sity by 8 AM EDT on Augus t 22. By 2 PM EDT on August 23, Andr ew possessed a cent ra l

pres sur e of 922 mb. It wa s at t he upper en d of category 4 str engt h (on t he Sa ffir-Simpson scale)

when its eye passed over the north ern pa rt of Eleuther a Islan d in the Bah am as on August 23an d the southern Berry Islan ds on August 24. Extensive dam age occurr ed in t hese regions.

Eleut her a experienced a high-wat er level (storm sur ge an d waves) of 25 feet (ft) at th e town of

The Curr ent.

Andr ew weak ened briefly on August 24, th en r apidly reinten sified. Once again, it deepened to

ha ve a m inimu m centr al pressur e of 922 mb a s it crossed the coast near Homestead Air F orce

Base (AFB), Florida, at 5:05 AM EDT, August 24. That pressure estimat e was substa nt iated

by pressure r eadings from bar ometer s nea r t he lan dfall, severa l of which were pressure cham ber

tested for accuracy following Andrew.

The storm was un usua lly compa ct. An a ircra ft penetr at ion less than an hour before landfallshowed tha t h ur ricane-force winds wer e confined to a region approxima tely 30 na ut ical m iles

(nm) in ra dius, with peak observed winds of 162 kn ots (kt s) (186 mph ) at a flight level of 10,000

ft (figur e 2). The ma ximum su sta ined 1-minu te sur face (10-met er elevat ion) winds over

south ern Florida were approxima tely 125 kts (144 mph).

The most severe dama ge occurred a long th e swath of the eye and in t he sur rounding eyewall.

Unofficial estimat es of the pressur e gradient in th e eyewall on the north side of the storm


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Figure 2


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indicat e tha t it ma y have been as large as 10 mb per nm. This is indicat ive of th e extrem e

winds largely responsible for th e tr emendous da ma ge.

Andrew was by far the most expensive natural disaster in United States history in terms of

proper ty loss (approxima tely $25 billion). In defian ce of th e convent iona l wisdom on hu rr ican e

effects in the Un ited Stat es, most of the da ma ge was cau sed by th e severe winds rat her t ha n t he

storm su rge. The dam age in Louisiana was su bsta nt ial, over $1 billion, with a bout $300 million

agricultur al impa ct. The tornado at La P lace was by far t he most dama ging Andrew-related

element to manmade structures in Louisiana.

Hur rican e Andrew cont inued westward a cross the south ern tip of the F lorida peninsula a nd

exited on th e west coast a bout 4 hours a fter it m ade landfall. The storm r ema ined inten se as

it crossed th e Gulf of Mexico, with su rface pressur e filling only to about 950 mb. Dur ing th e 48

hour s pr ior to landfall in Louisian a, t wo cycles of reinten sificat ion occur red, both th e resu lt of

intera ctions between high pressure t o th e north east an d a m id-latitude tr ough to the north west.

As the high weakened, the influence of the m id-lat itu de t rough becam e domina nt . Steering

winds across th e north ern gulf were altered; Andrew tu rned t o the west-north west a nd slowed

its forwa rd m otion t o 10 mph .

Andrew weakened prior to landfall, skirting Louisianas coastline for about 10 hours before

coming ashore near Point Chevreuil, about 20 nm west-southwest of Morgan City, Louisiana.

The storm m ade landfall at 4:30 AM EDT on Augu st 26. With a n estimat ed lan dfall centr al

pressur e of 956 mb an d susta ined winds of 120 mph , Andrew st ruck th e sparsely populated

portion of south -cent ra l Louisian a a s a category 3 hur rican e. It filled very ra pidly, weak ening

to tropical storm st ren gth by ear ly after noon a nd t o a depr ession by evening. On Augu st 28, the

rem na nt s of Andrew mer ged with a cold front an d were n o longer considered a tr opical weat her

system.

Wind Distributio n

Inten se, compa ct storms, such a s Andrew, are infrequent but n ot r ar e. They are chara cterized

by extrem ely strong pressure gradients a nd resulting intense winds in a nd nea r th e eyewall.

Figure 3a is a prelimina ry a na lysis of sur face winds of Hu rr ican e Andr ew OVER WATER nea r

th e time of land fall. The wind an alyses at flight level were reconst ru cted from ava ilable dat a

sources and em pirically adjust ed to estima te su rface values over wat er, using correction factors

appr opriate for over-wat er conditions . Su sta ined winds over lan d ar e typically weak er tha n

surface winds over wat er, but surface winds over land tend to ha ve larger gust factors t ha n over-

wat er sur face winds. Sup erim posed on the wind est ima tes of figur e 3a is a ma p of th e region

of sout her n F lorida wh ere Andrew m ade landfall, to give th e scale of th e storm an d of th e likely

regions of intense winds. Note th at th e strongest winds were ah ead a nd t o the right side, with

respect to storm motion, of th e storm an d, ther efore, a pproxima tely coincided with t he r egionsof ma ximu m da ma ge discussed elsewhere in th is report. It is possible tha t th e radius of

ma ximu m winds might h ave been a few miles smaller a t th e surface tha n is shown in these

an alyses since th e an alyses do not t ak e into accoun t outwa rd sloping of th e eyewall with h eight .

Figure 3b is a preliminar y estima te of th e over-wat er sur face winds a t t he a pproxima te time

th at Andr ew ma de lan dfall on the coast of Louisian a. A ma p of t he region is overla id for


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Figure 3a & Pr eliminary estim a te of the surface winds OVER WATER just before H urr ican e

Andr ew ma de lan dfall in Florida. These winds are estim at ed empirically from flight level

an alyses using corr ection factors a ppropriat e for over-water conditions only. A map of south ern

Florida is super imposed for r eference. (M. Powell, personal comm un icat ion)


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Figure 3b & As in figure 3a but for landfall in

Louisian a. (M. Powell, persona l

communication)


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MAX WINDS P ATH LENGTH P ATH WIDTH

(MP H) (MI) (YDS) (MI)

_____________________________________________________________________

F-0 < 73 P L0 < 1.0 P W0


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Rainfall and Flooding

The hydrologic impact of Hurricane Andrew, throughout the entire life of the system, was

genera lly minim al. While copious am ount s of ra in fell at some locations, ther e were no reports

of major flooding.

As Hur rican e Andrew passed over th e Baha ma s an d Florida, the st orm was compa ct a nd m oved

relatively ra pidly. This movement limited the dura tion and am oun t of ra infall. Heaviest

observed rainfall in Florida occurred inland across northwestern Dade and southwestern

Browar d Count ies, where am ount s ra nged up to 8 inches (all ra infall amount s ar e storm t ota ls;

see app endix A, ta bles A.1 an d A.2, for r ainfall observat ions). Virt ua lly no river flooding wa s

report ed across Florida in a ssociat ion with Andrews ra ins, ma inly due to the fact th at th e

heaviest ra ins fell to the sout h a nd east of west-centr al F loridas river basins a nd instea d

occur red over t he m ar shlan ds of the E verglades r egion. Some localized urba n-type flooding did

occur at severa l locations across sout h F lorida .

In Louisiana , Hurr ican e Andrews ra infall patt ern was a ctua lly quite similar t o past hur rican es

str iking the centr al gulf coast r egion & th at of Hurr ican e Betsy (Louisian a, September 1965) an dHu rr ican e Camille (Mississippi, August 1969). In th e cases of Hu rr ican es Betsy and Cam ille,

the h eaviest r ains were generally along an d to the east of the pat hs of th e hur rican es. Likewise,

based on prelimina ry data , the hea viest ra infall ass ociat ed with H urr ican e Andrew was a lso

along an d to the right of the pa th of the h urr ican e although the r ainfall patt ern with Hu rrican e

Andr ew was somewha t m ore widespread t ha n with Betsy and Ca mille. Additiona lly, ma ximu m

observed rainfall amounts were also similar for a ll th ree hu rrican es. The ma ximu m observed

single ra infall from Hu rr ican e Andr ew occur red a t Ha mm ond, Louisian a, locat ed in Ta ngipah oa

Parish in east-central Louisiana, where 11.92 inches fell (see appendix E, figure E.2, for

Louisian a r ainfall an alysis). Also, 9.30 inches of ra in was r ecorded nea r Su mr all, Mississippi,

locat ed in sout h-centr al Mississippi, near Ha tt iesbur g.

Still, despite the heavy rainfall, very little in the way of significant flooding developed in

Louisian a an d surr oun ding stat es. This was prima rily due to the fac

Hurricane Andrew: Natural Disaster Survey Rpt, U.S. Dept Commerce, 1993

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Transcript of Hurricane Andrew: Natural Disaster Survey Rpt, U.S. Dept Commerce, 1993