Chris Landsea NOAA/Hurricane Research Division Miami, Florida, USA CSU/CIRA April 2 nd , 2004

The Atlantic Hurricane Database The Atlantic Hurricane Database Re-analysis Project – Results for 1851 to Re-analysis Project – Results for 1851 to

1910 and 1992’s Hurricane Andrew1910 and 1992’s Hurricane AndrewChris Landsea

NOAA/Hurricane Research Division

Miami, Florida, USA

CSU/CIRA

April 2nd, 2004Co-Authors: Craig Anderson, Noel Charles, Gil Clark, Peter Dodge, Jason Dunion,

Jose Fernandez-Partagas, James Franklin, Paul Hungerford, Charlie Neumann, Mark Zimmer, and the NHC Best Track Change Committee

Acknowledgments: Sim Aberson, Auguste Boissonnade, Emery Boose, Mike Chenoweth, Hugh Cobb, Jose Colon, Neal Dorst, Paul Hebert, Brian Jones, Lorne

Ketch, Cary Mock, Ramon Perez Suarez, David Roth, Al Sandrik, and David Vallee.

What is the historical hurricane database and how is it utilized?

Why revise HURDAT and how is it done?Databases providedResults thus far:

– Example: The 1886 Indianola Hurricane– 1851 to 1910– Hurricane Andrew

The Atlantic Hurricane The Atlantic Hurricane Database Re-analysis ProjectDatabase Re-analysis Project

Acknowledgment: NOAA grant (NA7P0369), a grant from the Risk Prediction Initiative and supplemental funding from the Insurance Friends of NHC

NOAA Dork LogoNOAA Dork Logo Track andIntensity Forecast

Developmentand

Verification

Climate Variability and Change Studies

Building Codes andInsurance Rates

HURDAT -Developed in the

late 1960s in support of the Apollo

space program

Hurricane Bret (1999)

Intensity Estimates and “Best Track” Values

Center Fix and “Best Track”

Jarvinen et al. (1984)

Smoothed Representation in Best Track

Neumann et al. (1999)

Observational Platforms for Atlantic Hurricanes

Incorrect intensity

and location at landfall

Too Rapid DuringLast 6 Hours

Pressure-Wind Relationship

Atlantic Major Hurricanes

Landsea (1993)

Bias-removed

Franklin and Black (1999)

Mean Wind ProfileWind in Hurricane Georges

GPS DropsondesGPS Dropsondes Measures the wind around and in hurricanes

from the aircraft to the ocean’s surface

Work of Jose Partagas: Historical Reconstruction from 1851-1910

ShipTracks

Using ShipObservations to

Estimate theHurricane’s

Location

Estimating Intensity with and without Aircraft Reconnaissance

The Beaufort Wind ScaleBeaufort Knots Description Number

0 < 1 Calm

1 1-3 Light air

2 4-6 Light breeze

3 7-10 Gentle breeze

4 11-16 Moderate breeze

5 17-21 Fresh breeze

6 22-27 Strong breeze

7 28-33 Near gale

8 34-40 Gale

9 41-47 Strong gale

10 48-55 Storm

11 56-63 Violent storm

12 > 63 Hurricane

ATLANTIC WIND/PRESSURE RELATIONSHIPS

Winds (knots) computed from regional P/W relationships

P(MB) GLFMEX <25N 25-35N 35-45N KRAFT P(MB) P(IN)

960 100 100 94 90 102 960 28.35

1)For GLFMEX: Wind(knots)=10.627*(1013-p)**0.5640 Sample size =664; r=0.991

2)For <25N Wind(knots)=12.016*(1013-p)**0.5337 Sample size =1033; r=0.994

3)For 25-35N Wind(knots)=14.172*(1013-p)**0.4778 Sample size =922; r=0.996

4)For 35-45N Wind(knots)=16.086*(1013-p)**0.4333 Sample size =492; r=0.974

5)For Kraft Wind(knots)=14.000*(1013-p)**0.5000 Sample size =13; r= ??

Estimating the Central Pressure

(Pr – Pc)/(Pe – Pc) = exp(-RMW/R)

Storm Surge

Surveys of Wind-caused Damage

Estimated central pressure from Ho (1989) of 915 mb at landfall in Texas is incorrect since it relied upon a pressure measurement from San Antonio, Texas, which has been found to be a surface pressure rather than a sea level pressure value. Additionally, it is likely that this was not a central pressure measurement either as strong winds were still observed at the time of lowest pressure and that winds only shifted from northeast to southeast. This sea level pressure measurement of 971 mb (corrected from the 948 mb surface pressure value) at 19Z on the 20th implies a central pressure of around 965 mb, assuming that the RMW estimate of Ho (of 12 nmi) is slightly too small (15 nmi utilized instead). 965 mb suggests winds of 94 kt from the Gulf of Mexico wind-pressure relationship for a marine exposure - 85 kt utilized in best track for this inland location. Using methodology in Ho et al. (1987) as modified by B. Jarvinen (personal communication), a 6.5 hr transit time from landfall to a position near San Antonio, and the 965 mb central pressure near San Antonio, a new value of 925 mb at landfall is estimated for this hurricane. This suggests winds of 133 kt from the Gulf of Mexico wind-pressure relationship. The estimate of 15 nmi for RMW is slightly smaller than climatology (18 nmi) for this latitude and central pressure (Vickery et al. 2000), supporting slightly stronger winds for this particular storm. 135 kt is chosen as the maximum sustained winds at landfall. This is consistent with the very high storm tide and extreme destruction in Indianola, Texas. Storm surge modeling efforts with the SLOSH model (B. Jarvinen, personal communication) indicate that a 925 mb central pressure and RMW of 15 nmi provides reasonable matches to observed surge values. Positions are altered slightly after landfall to better account for passage of the hurricane's center near San Antonio at 19Z on the 20th. A storm tide of 15' was reported for Indianola, Texas in Roth (1997b).

Metadata File for Storm #5, 1886:

1886/05 (Synoptic/intensity):

Date Time Wind/Dir Pressure Location Source

8/14/1886 ???? UTC 80 kt/ESE-SW ???? mb 17.7N 67.5W "Gertie M. Rickerson"

8/15/1886 0700 UTC ? kt/N-SE 1000 mb 18.8N 70.0W Santo Domingo

8/17/1881 2000 UTC 50 kt/NE-WS ???? mb 22.5N 80.0W Cardenas

8/18/1880 ???? UTC 50 kt/NE-SE 1005 mb 24.8N 82.0W Key West

8/18/1886 0900 UTC 70 kt/NE-S 994 mb 24.0N 82.5W "Manhattan"

8/19/1886 0700 UTC 60 kt/NE-SE ???? mb 24.8N 83.0W "Arbutus"

8/20/1886 1400 UTC 70 kt/E 999 mb 28.4N 96.8W Indianola

8/20/1886 1930 UTC ? kt/?? 971 mb 29.6N 98.5W San Antonio

1886/05 (Center positions):

Date Time Location Source

8/20/1886 1930 UTC 29.6N 98.5W San Antonio

Center Fix Data for 1886/5:

August 19 0 UTC 25.6N 87.9W 280 deg 16 kt 18 mph 29 kph 80 kt 95 mph 150 kph -- mb Hurricane - Category 1

August 19 6 UTC 25.9N 89.7W 280 deg 16 kt 18 mph 29 kph 90 kt 105 mph 170 kph -- mb Hurricane - Category 2

August 19 12 UTC 26.3N 91.9W 280 deg 20 kt 23 mph 37 kph 100 kt 115 mph 180 kph -- mb Major Hurricane - Category 3




August 20 12 UTC 28.0N 96.6W 305 deg 10 kt 11 mph 18 kph 135 kt 155 mph 260 kph 925 mb Major Hurricane - Category 4

August 20 18 UTC 28.8N 97.6W 310 deg 11 kt 12 mph 20 kph 85 kt 100 mph 160 kph 965 mb Hurricane - Category 1

August 21 0 UTC 29.7N 98.4W 320 deg 11 kt 12 mph 20 kph 60 kt 70 mph 110 kph -- mb Tropical Storm



August 21 18 UTC 33.5N 101.3W 325 deg 18 kt 20 mph 33 kph 25 kt 30 mph 50 kph -- mb Tropical Depression

Month Day Hour Lat. Long. Dir. --------Speed--------- ---------Wind----------- Pres. ------------Type-----------

Revised “Best Track” (HURDAT) Data for 1886/05:

U.S. Landfalling Hurricanes#/Date Time Lat Lon Max SS# RMW Storm Central States

Wind Surge Pressure Affected 5-8/20/1886 1200Z 28.0N 96.6W 135kt 4 15nmi --- 925mb BTX4

Minutes of the NHC best-track change commmittee meeting

Members Jack Beven, Jim Gross, Richard Pasch, Ed Rappaport, and chair (Colin McAdie) present. (meeting 5 – 22 March, 2002)

The committee met to continue consideration of the most recent set of best-track changes provided by Chris Landsea et al. The committee resumed discussion with storm 1 of 1897, as agreed, completed discussion on the second third (1890-1899) of the material and then proceeded through storm 5 (becoming 6) of 1901.

Jack Beven noted that the use of 3- or 4-cup anemometers in the early portion of the record could affect wind estimates. Although there may be a systematic way to handle this, it is not clear whether this has been accounted for.

< Yes, this has been accounted for as best possible. In use during the period being revised - 1851 to 1910,

though anemometers were mainly available from the 1870s onward at coastal stations - was the four

cup Robinson anemometer. However, the primary difficulties with this instrument were its calibration and its

mechanical failure in high wind conditions. Even as late as 1890, the highest wind that could be reliably

calibrated with this instrument was only about 30 kt (from a whirling machine), due to lack of a strict

comparison with a known quantity of stronger winds (Fergusson and Covert 1924)…. >

Estimated average position and intensity errors in best track for the years 1851-1910. Negative bias errors indicate an underestimation of the true intensity._________________________________________________________________________ Situation Dates Position Intensity Error Intensity Error

Error (absolute) (bias)_________________________________________________________________________Open ocean 1851-1885 120 nmi/220 km 25 kt/13 m s-1 -15 kt/-8 m s-1

1886-1910 100 nmi/185 km 20 kt/10 m s-1 -10 kt/-5 m s-1

Landfall in 1851-1885 120 nmi/220 km 25 kt/13 m s-1 -15 kt/-8 m s-1 unsettled area 1886-1910 100 nmi/185 km 20 kt/10 m s-1 -10 kt/-5 m s-1

Landfall at 1851-1885 60 nmi/110 km 15 kt/8 m s-1 0 kt/0 m s-1

settled area 1886-1910 60 nmi/110 km 12 kt/6 m s-1 0 kt/0 m s-1

____________________________________________________________________________

Strongest U.S. Hurricane – 1851 to 1910

Most Intense (Category 3, 4, 5) Continental United States Hurricanes: 1851-1910

#/Date Time Lat Lon Max Saffir- Storm Central States Winds Simpson Surge Pressure Affected

5-8/20/1886 1300Z 28.1N 96.8W 135kt 4 15' 925mb BTX4 1-8/10/1856$ 1800Z 29.2N 91.1W 130kt 4 11-12'% 934mb LA4 1-9/9/1900 0140Z 29.1N 95.1W 125kt 4 20'% 936mb CTX4 10-10/2/1893 0800Z 29.3N 89.8W 115kt 4 --- 948mb LA4 7-10/2/1898 1600Z 30.9N 81.4W 115kt 4 16' 938mb GA4,DFL2 6-9/16/1855$ 0300Z 29.2N 89.5W 110kt 3 10-15'% (950mb) LA3,MS3 1-8/11/1860$ 2000Z 29.2N 90.0W 110kt 3 12'% (950mb) LA3,MS3,AL2 4-9/1/1879$ 1600Z 29.5N 91.4W 110kt 3 --- (950mb) LA3 2-8/13/1880# 0100Z 25.8N 97.0W 110kt 3 --- 931mb ATX3 3-8/16/1888$ 1900Z 25.8N 80.1W 110kt 3 14'% (945mb) CFL3,BFL1 4-9/29/1896 1100Z 29.2N 83.1W 110kt 3 --- 960mb AFL3,DFL3,GA2,SC1,NC1,VA1 10-10/12/1886 2200Z 29.8N 93.5W 105kt 3 12'% (955mb) LA3,CTX2 9-10/13/1893 1300Z 33.0N 79.5W 105kt 3 14'% 955mb SC3,NC2,VA1 5-10/9/1894 0300Z 30.2N 85.5W 105kt 3 --- (955mb) AFL3,GA1 3-8/18/1899 0100Z 35.2N 75.8W 105kt 3 --- (945mb) NC3 8-10/18/1906 0930Z 24.7N 81.1W 105kt 3 --- 953mb BFL3,CFL3 8-9/21/1909 0000Z 29.5N 91.3W 105kt 3 15'% 952mb LA3,MS2 4-8/23/1851$ 2100Z 30.1N 85.7W 100kt 3 12'% (960mb) AFL3,GA1 1-8/26/1852 0600Z 30.2N 88.6W 100kt 3 12'% 961mb AL3,MS3,LA2,AFL1 2-9/8/1854 2000Z 31.7N 81.1W 100kt 3 --- 950mb GA3,SC2,DFL1 6-9/8/1869 2200Z 41.4N 71.7W 100kt 3 8'% 965mb RI3,MA3,CT1 3-8/17/1871$ 0200Z 27.1N 80.2W 100kt 3 --- 955mb CFL3,DFL1,AFL1 5-10/7/1873$ 0100Z 26.5N 82.2W 100kt 3 14'% 959mb BFL3,CFL2,DFL1 3-9/16/1875 2100Z 27.7N 97.2W 100kt 3 15'% (960mb) BTX3,ATX2 4-10/3/1877$ 0500Z 30.0N 85.5W 100kt 3 12'% (960mb) AFL3,GA1 2-8/18/1879 1200Z 34.7N 76.7W 100kt 3 7' 971mb NC3,VA2 2-9/10/1882 0200Z 30.4N 86.8W 100kt 3 --- 949mb AFL3,AL1 2-8/25/1885 0900Z 32.2N 80.7W 100kt 3 --- (953mb) SC3,NC2,GA1,DFL1 6-8/28/1893 0500Z 31.7N 81.1W 100kt 3 9-10' 954mb GA3,SC3,NC1,DFL1 4-7/21/1909 1650Z 28.9N 95.3W 100kt 3 10'% 959mb CTX3 10-10/11/1909 1800Z 24.7N 81.0W 100kt 3 --- 957mb BFL3,CFL3

Longest lived hurricane on record

Four Hurricanes Simultaneously

U.S. DeadliestHurricanes of

the 19th Century

Busiest U.S. Hurricane Season on Record

Changes to U.S. Hurricanes - 1899 to 1910

#/Date Original 2003 HURDAT Category/State HURDAT Revision Changes

2-8/1/1899 TS AFL2 Upgrade by two categories 3-8/18/1899 NC3 NC3 No change 8-10/31/1899 NC3,SC3 NC2,SC2 Downgrade by a category 1-9/9/1900 CTX4 CTX4 No change 3-7/11/1901 NC1 NC1 No change 4-8/14-15/1901 LA2,MS2 LA1,MS1,AL1 Downgrade by a category, add in Alabama 1902 - No U.S. hurricanes 3-9/11&13/1903 CFL2,AFL1 CFL1,AFL1 Downgrade by a category in SE Florida 4-9/16/1903 NJ1,NY1 NJ1,DE1 No change in category, add in Delaware, remove New York 2-9/14/1904 SC1 SC1 No change 3-10/17/1904 TS CFL1 Upgrade by a category 1905 - No U.S. hurricanes 2-6/17/1906 CFL1 BFL1,CFL1 No change in category, add in SE Florida 5-9/17/1906 SC3,NC3 SC1,NC1 Downgrade by two categories 6-9/27/1906 MS3,AL3 MS2,AL2,AFL2,LA1 Downgrade by a category, add in NW Florida and Louisana 8-10/18/1906 CFL2 BFL3,CFL3 Upgrade by a category, add in SW Florida 1907 - No U.S. hurricanes 3-7/31/1908 NC1 NC1 No change2-6/29/1909 TS ATX2 Upgrade by two categories 4-7/21/1909 CTX3 CTX3 No change 6-8/27/1909# ATX2 ATX1 Downgrade by a category 8-9/21/1909 LA4 LA3,MS2 Downgrade by a category, add in Mississippi 10-10/11/1909 CFL3 BFL3,CFL3 No change in category, add in SW Florid3-9/14/1910 ATX2 ATX2 No change 5-10/17/1910 BFL3 BFL2 Downgrade by a category

Notes: Overall: 2 hurricanes upgraded 2 categories, 2 hurricanes upgraded 1 category, 10 hurricanes no change in category, 7 hurricanes downgraded 1 category, 1 hurricane downgraded 2 categories.

Incomplete

Records

“Settled Area” In 1850

Busy Atlantic Seaboard Decade – The 1890s

Sandrik and Landsea (2003)

Three MajorHurricanesIn Georgia

Atlantic Hurricane Re-Analysis Project

1. Re-analysis results for 1851 to 1910 a. Overview and Highlights b. Documentation c. Data

2. Hurricane Andrew's Upgrade

3. Books by Jose' Fernandez Partagas

Picture from: "Florida's Hurricane History", by Jay Barnes

http://www.aoml.noaa.gov/hrd/data_sub/re_anal.html

1911 through 1940 being re-analyzed currently (working with William Bredemeyer, Steve Feuer, John Gamache and Lenworth

Woolcock)

NOAA Dork LogoNOAA Dork Logo

RECON FLIGHT-LEVEL WINDS

HURRICANE GEORGES 9/20/98 20-23Z

105 kt

90 kt

90 kt95 kt

But nobody lives at 10,000 ft.

How can we use flight-level data to estimate surface winds?

In the early 1990’s, reduction factors used by NHC ranged from 75%-90% of the flight-level wind.

Powell and Black (1990) concluded 63-73% for 700mb to surface reduction factor, but had few eyewall high-wind cases.

EYEWALL SCHEMATICEYEWALL SCHEMATIC

AIRCRAFT TRACK

DROPSONDE TRAJECTORY

100 90 80 70 10000 ft

~1-2 miles

AVERAGE OF 357 GPS DROPSONDE PROFILES IN THE HURRICANE EYEWALL.

ON AVERAGE, THE SURFACE WIND IS 90% OF THE WIND AT 700 MB AIRCRAFT RECONNAISSANCE LEVELS (75-80% AT LOWER ALTITUDES).

Franklin et al. (2002)

New H*WIND Analysis For Hurricane Andrew

150 kt – 93% of flight level

Some New Hurricane Andrew Data:Radar Feature Tracking

Flight-level wind to surface extrapolation 145 kt (+10)

Feature tracking from the Miami radar145 kt (+15) Pressure-wind relationships 145 kt (+20)

Satellite intensity estimates 145 kt (+20) Storm surge and SLOSH implications 145 kt (+25)

Structural damage survey estimates 135 kt (+30)

The Re-analysis The Re-analysis of Hurricane Andrew (1992)of Hurricane Andrew (1992)

Revised Best Track

A RE-ANALYSIS OF ANDREW’S INTENSITY

1992’s Hurricane Andrew originally was assessed as a Category 4 hurricane, based primarily upon extrapolation of flight-level winds to the surface.

Research using GPS dropwindsondes in the late 1990s and early 2000s has demonstrated that stronger winds exist at the surface the hurricane eyewall than originally believed.

A re-analysis indicates that Hurricane Andrew reached Category 5 status at its landfall in both the northern Bahamas and in southeastern Florida (145 kt +10 kt).

Because of this reclassification, the return period of catastrophic hurricanes like Andrew increases from about 30 years to around a century for southeastern Florida. Thus the risk from Andrew-like hurricanes there is significantly LESS than previously estimated.

What is the historical hurricane database and how is it utilized?

Why revise HURDAT and how is it done?Databases providedResults thus far:

– Example: The 1886 Indianola Hurricane– 1851 to 1910– Hurricane Andrew

The Atlantic Hurricane The Atlantic Hurricane Database Re-analysis ProjectDatabase Re-analysis Project

Acknowledgment: NOAA grant (NA7P0369), a grant from the Risk Prediction Initiative and supplemental funding from the Insurance Friends of NHC

“Settled Area” In 1890

Atlantic Multidecadal ModeLocal Correlation of SST versus REOF

Mestas-Nunez and Enfield (1999)

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

SS

T (°

C)

1870

1874

1878

1882

1886

1890

1894

1898

1902

1906

1910

1914

1918

1922

1926

1930

1934

1938

1942

1946

1950

1954

1958

1962

1966

1970

1974

1978

1982

1986

1990

1994

1998

Atlantic SST Multidecadal Mode (AMM) (rotated)

Annual means and 5-year RM for N. Atlantic Box from Goldenberg et al. Science, July 20, 2001

WHAT IS THE INTENSITY OF A TROPICAL WHAT IS THE INTENSITY OF A TROPICAL CYCLONE AND HOW IS IT MEASURED TODAY?CYCLONE AND HOW IS IT MEASURED TODAY?

Maximum sustained surface wind: Maximum wind, averaged over 1 minute interval at an altitude of 33 ft (10 m), associated with the circulation of the tropical cyclone at a given point in time.

With very, very few exceptions, direct observations of the maximum sustained surface wind in a tropical cyclone are not available.

Satellite imagery using the Dvorak techniqueAircraft reconnaissance flight-level winds

GPS dropwindsondes

EYEWALL STRUCTURE CAN VARY SIGNIFICANTLY FROM STORM TO STORM, OR EVEN DURING DIFFERENT STAGES OF THE LIFE CYCLE OF A SINGLE STORM.

Franklin et al. (2002)

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

Bin Ave (R/Rmax: 0.1 bins)

Data

Inside Flight-Level RMW

Apply x1.3 boost if R/Rmax <0.25 and R/Rmax>=0

Apply polynomial if R/Rmax <=2.0 and

Outside Flight Level

UMBL = U700 [2.31x10 -1(R/RMW) 3 - 6.82x10 -1(R/RMW)2 + 3.04x10-1(R/RMW) + 1.26]

Distance as a Function of RMW

MBLto

700mbRatio

Step 1: Flight Level to a Mean Boundary Layer (0 to 500m)

Dunion, Landsea, Houston and Powell (2002); Dunion and Powell (2002)

USFC = UMBL[-2.84x10 -7 (UMBL)3 + 1.58x10 -4 (UMBL)2 - 1.25x10 -2 (UMBL) + 1.08]

0.50

0.60

0.70

0.80

0.90

1.00

1.10

0 10 20 30 40 50 60 70 80

Data

Bin Ave (w/ 5 min gust)

HRD PBL Model

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Use 0.9(W MBL) if

WMBL >72 ms-1

Apply polynomial

if WMBL >=55 ms-1

and <=72 ms-1

Use PBL model if

WMBL <55 ms-1

MBL Wind Speed (ms-1)

MBL Wind Speed (mph)

Surf

ace

Win

d Sp

eed

/ MB

L W

ind

Spee

d

Step 2: Mean Boundary Layer (0 to 500m) to the Surface

Dunion, Landsea, Houston (2002); Dunion and Powell (2002)

Hurricane Andrew -Satellite Dvorak Estimates

127 kt/935 mb

Hurricane Andrew’sStorm Surge

And SLOSH Runs

Structural DamageSurveys of Hurricane Andrew

Documents

Chris Landsea NOAA/Hurricane Research Division Miami, Florida, USA CSU/CIRA April 2 nd , 2004