National Weather Service, Mobile-Pensacola

Extremely Powerful Hurricane Katrina leaves a Historic Mark on the Northern Gulf Coast

A Killer Hurricane Our Country Will Never Forget –

 

Hurricane Katrina (August 2005) became a large and
extremely powerful hurricane that caused enormous
destruction and significant loss of life. It is the costliest
hurricane to ever hit the United States, surpassing the
record previously held by Hurricane Andrew from 1992.
In addition, Katrina is one of the five deadliest hurricanes
to ever strike the United States. In all, Hurricane Katrina
was responsible for 1,833 fatalities and approximately
$108 billion in damage (unadjusted 2005 dollars).

On August 23rd, a tropical depression formed over the
southeastern Bahamas, becoming Tropical Storm Katrina
on August 24th as it moved into the central Bahamas. The
storm continued to track west while gradually intensifying
and made its initial landfall along the southeast Florida coast on August 25th as a Category 1 hurricane (80mph) on the Saffir-Simpson Hurricane Scale. After moving west across south Florida and into the very warm waters of the Gulf of Mexico, Katrina intensified rapidly and attained Category 5 status (with peak sustained winds of 175mph) for a period of time as she moved northwest on August 28th. Katrina weakened to a Category 3 before making landfall along the northern Gulf Coast, first in southeast Louisiana (sustained winds: 125mph) and then made landfall once more along the Mississippi Gulf Coast (sustained winds: 120mph). Katrina finally weakened below hurricane intensity late on August 29th over east central Mississippi.

The damage and loss of life inflicted by this massive hurricane in Louisiana and Mississippi was staggering with significant effects extending into Alabama and the western Florida panhandle. This was a storm that captivated the public and media with most coverage occurring in the New Orleans area. Considering the scope of its impacts, Katrina was one of the most devastating natural disasters in United States history.

As Katrina set new minimum central pressure records
while approaching the northern Gulf Coast on Sunday,
August 28th, the storm made its final turn to the nort
h
as it moved toward southeastern Louisiana. Katrina was
a large storm with a very
distinct eye. Early on the 28th,
Katrina reached a minimum central pressure of 902mb
(at the peak) - ranking 7th lowest on record for all Atlantic
Basin hurricanes - and rapidly intensified to a Category 5
(175mph).

Katrina then weakened to a Category 4 hurricane as it
moved across the north central Gulf and weakened
further to a strong Category 3 hurricane shortly before
ma
king landfall in southeast Louisiana. The central
pressure at landfall was 920mb - ranking 3rd lowest on
record for a US landfalling hurricane, behind Hurricane Camille in 1969 (900mb) and the Labor Day Hurricane that struck the Florida Keys in 1935 (892mb).

The storm continued moving north-northeast and made a second landfall over Hancock County, Mississippi (near the mouth of the Pearl River) - still Category 3. After Katrina moved inland into southern Mississippi on the afternoon of August 29th, the storm left a wake of devastation that will never be forgotten. The loss of life and property damage was heightened by breaks in the levees that separate New Orleans from Lake Pontchartrain. At least 80% of New Orleans was under flood waters on August 31st.

 

 Photo courtesy of NCDC


 Although much will be written on the effects associated with this storm, this document will remain focused on Hurricane Katrina's impacts over inland southeastern Mississippi, southwestern Alabama and the extreme northwestern Florida Panhandle. Below are some of the regional impacts...
Jump to - Storm Surge, Wind, Tornadoes, Rainfall, Animations, Imagery, or Additional Information sections.

 

STORM SURGE

Known for its storm surge, Katrina’s highest surge was
found in a zone from just east of the eye near Bay St.
Louis, MS east to the northern reaches of Mobile Bay.
The Mobile State Docks measured the highest storm
surge of 11.45 feet, while the lowest was 4.1 feet in the
Santa Rosa Sound in northwest Florida. Storm surge
was as high as 12-14 feet in Bayou La Batre, AL and
likely close to 20 feet along the Mississippi-Alabama
border.

Many homes were engulfed by Katrina’s surge in
Bayou La Batre, AL. The surge in Mobile Bay led to
inundation of downtown Mobile causing the imposition
of a dusk-to-dawn curfew. The Mobile State Docks surge
value of 11.45 feet was very close to being the highest value ever recorded. The previous record of 11.60 feet was set on July 5, 1916. [The exact location and degree of accuracy of the 1916 record surge value is unknown.]

No lives were lost due to the storm surge across Mobile and Baldwin Counties in southern Alabama. Long lead warning times were given by the NWS Offices in Mobile, AL and New Orleans, LA as to how high the surge would be. As early as two days before landfall, the NWS Office in Mobile issued a Hurricane Local Statement (at 725pm) that foretold of the historic storm surge values of 8-12 feet well east of Katrina's center.

Storm Surge Map depicting a portion of storm surge data.

 

Table 1 - Observed storm surge data
Note: Highest tides occurred August 29, 2005

Tide Gage
Highest Tide (MSL)
Time (UTC)
Mobile State Docks (MBRA1)
11.45
1848
USS Alabama (estimated)
12.00
 
Dauphin Island (DAUA1)
6.63
1645
Dauphin Island (DPIA1)
6.23
1542
Perdido Pass (PPSA1)
5.81
1336
Pensacola (PENF1)
 5.37
 
Destin (EPSF1)
4.52
1336
Santa Rosa Sound (FWLF1)
4.10
1654


WIND

Katrina’s maximum landfalling windspeeds near Grand Isle,
LA may have been as high as 140mph. As Katrina moved
further north and made a second landfall along the Mississippi/
Louisiana border, the NWS Doppler Radar in Mobile (KMOB)
measured winds up to 132mph between 3,000-4,000 feet
above ground level in the morning. It is estimated that
80-90% (approximately 104-119mph) of the maximum wind
speed value actually reached the ground. 

Tree damage across Stone and George Counties in south
Mississippi was very similar to the damage produced by
Hurricane Ivan (2004) across Atmore and Brewton in south
central Alabama.

In this velocity loop (759-859am CDT), the eye of the storm,
denoted by the large white circle, is southwest of the region
of maximum surface wind speeds. These measurements are
the winds flowing toward KMOB radar. [Color scale where the next highest velocity values begin:
gray = 104mph; brown = 109mph; dark blue = 114mph; cyan = 117mph; green >127 mph]

The wind gust analysis map shown below is courtesy of the NWS Office in Jackson, MS.

 

 Table 2 - Sustained Winds and Maximum Wind Gusts
Note: Wind data occurred August 29, 2005

Location
Sustained Wind (knots)
Peak Gust, Time (knots, UTC)
Mobile Regional Airport (KMOB)
57
72 at 1608
Brookley Field (KBFM)
58
73 at 1501
Destin (KDTS)
30
44 at 1727
Pensacola Airport (KPNS)
49
60 at 1451
Crestview (KCEW)
30
38 at 1842
Evergreen (KGZH)
32
42 at 2118
Eglin AFB (KVPS)
33
46 at 1709
Mary Esther (KHRT)
38
52 at 1521
Pensacola Naval Air Station (KNPA)
49
62 at 1812
Eglin AFB
51
60 at 1452
Dauphin Island (DPIA1)
64
89 at 1542
Pensacola (WEAR-TV)
 
50
Mobile Bay (USS Alabama)
 
90
Holley Middle School, FL
 
40
Destin Middle School, FL
 
37
Wright Elementary School, FL
 
39
Semmes
 
57
 


TORNADOES

The outer bands of Hurricane Katrina produced numerous tornadoes throughout the southeastern US on August 28-29, especially across southern Alabama and the northwest Florida panhandle. In total, four tornadoes rated F0 occurred in southern Alabama (2- Mobile County, 1- Baldwin County, 1- Escambia County) and five tornadoes rated F0 occurred in the northwest Florida panhandle (2- Okaloosa County, 2- Santa Rosa County, 1- Escambia County).

A majority of the outer band tornadoes were brief and on the ground for 1/2 mile to two miles. The largest tornado path occurred in Santa Rosa County near Munson, FL and was on the ground for three miles. Further inland across areas covered by the NWS Offices in Jackson, MS and Birmingham, AL, tornadoes were rated F1-F2 with slightly longer paths.

Most of the damage associated with these weak outer band tornadoes was tree and power line damage. No fatalities or injuries occurred with these tornadoes.

NOTE: The F scale was used to rate these tornadoes back in 2005. As of 2007, the NWS now uses the EF scale to rate tornadoes.

 


RAINFALL

KMOB radar showed the greatest rainfall amounts occurred east of Katrina’s eye and very close to the coast. A general 5-10 inches of rain fell with isolated amounts exceeding 12 inches. Rainbands extending well east of Katrina’s eye brought isolated rainfall totals of 3-5 inches over extreme northwest Florida. Significantly lighter rainfall amounts (less than 2 inches) fell east of a line from Camden, AL to Evergreen, AL to Navarre, FL.

Here is a look at the rainfall map for the southeastern US during Hurricane Katrina's lifetime (August 24-30). Photo courtesy of NCDC.

 

Table 3 - 48 hour total rainfall (inches) ending at 1159pm on August 29, 2005

Location
48 hour rainfall (inches)
Mobile Regional Airport (KMOB)
3.80
Thomasville
3.17
Semmes
5.70
Pensacola (WEAR-TV)
3.06
Daphne
4.97
Philpot, FL
7.80
Milton
4.50
Molino
5.00
Oak Grove
6.00
6 hour total for Mobile Regional Airport (KMOB) --> 1.43 inches ending at 1359 UTC on August 29


Animations

Animated Radar Imagery
Animated Satellite Imagery
Colorized IR Satellite Loop
Regional Satellite Loop
HURSAT-AVHRR Satellite Imagery

 

ImageryLink to Coastal Aerial Photos

High Water Mark Collection for Alabama
NOAA Coastal Aerial Photos

Pre- and Post-Katrina 3D Topography: Dauphin Island, AL

Before and After Photos: Dauphin Island, AL
USGS Post-Storm Photos (zoom in for details)

NOAA Hurricane Hunter Imagery INSIDE Katrina
NOAA Photo Library of Katrina

LOCAL Damage Photos:

     Coden / Bayou La Batre

     Dauphin Island

     Downtown Mobile
     Fairhope / Point Clear
     Dog River
     Stone/George County, MS
     Northwest Florida panhandle

 

More Information (Technical Papers and Assessments)

NWS Service Assessment everything you want or need to know!
NCDC Technical Report

NHC Advisory Archive

NWS Post-Tropical Cyclone Reports - Katrina
     NWS Mobile, AL

     NWS New Orleans, LA


NCDC Special Report - Katrina

NHC Tropical Cyclone Report - Katrina

NWS Katrina Local Write-Ups and Webpages:
     NWS New Orleans
     NWS Jackson
     NWS Birmingham
     NWS Huntsville

    
NWS Memphis
     NWS Shreveport

     NWS Nashville

 


Acknowledgements: Page created by Jeffrey Medlin (MIC), Ray Ball (ITO) and Gary Beeler (former WCM) with contributions from members of the NWS Mobile staff. Updated by Morgan Barry (forecaster), Jason Beaman (WCM) and Don Shepherd (senior forecaster, Tropical Focal Point).

LAST UPDATED: August 2015


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.