The Atlantic Hurricane Database Re-analysis Project – Results for 1851 to 1910 and 1992’s Hurricane Andrew The Atlantic Hurricane Database Re-analysis Project – Results for 1851 to 1910 and 1992’s Hurricane Andrew Chris Landsea NOAA/Hurricane Research Division Miami, Florida, USA CSU/CIRA April 2 nd, 2004 Co-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 provided Results thus far: – Example: The 1886 Indianola Hurricane – 1851 to 1910 – Hurricane Andrew The Atlantic Hurricane Database Re-analysis Project The Atlantic Hurricane Database 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 Logo Track and Intensity Forecast Development and Verification

Climate Variability and Change Studies

Building Codes and Insurance 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 During Last 6 Hours

Pressure-Wind Relationship

Atlantic Major Hurricanes Landsea (1993) Bias-removed

Franklin and Black (1999) Mean Wind Profile Wind in Hurricane Georges GPS Dropsondes Measures the wind around and in hurricanes from the aircraft to the ocean’s surface

Work of Jose Partagas: Historical Reconstruction from

Ship Tracks

Using Ship Observations to Estimate the Hurricane’s Location

Estimating Intensity with and without Aircraft Reconnaissance

The Beaufort Wind Scale Beaufort Knots Description Number 0 < 1 Calm Light air Light breeze Gentle breeze Moderate breeze Fresh breeze Strong breeze Near gale Gale Strong gale Storm 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) )For GLFMEX: Wind(knots)=10.627*(1013-p)** Sample size =664; r= )For <25N Wind(knots)=12.016*(1013-p)** Sample size =1033; r= )For 25-35N Wind(knots)=14.172*(1013-p)** Sample size =922; r= )For 35-45N Wind(knots)=16.086*(1013-p)** Sample size =492; r= )For Kraft Wind(knots)=14.000*(1013-p)** 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/ UTC ? kt/N-SE 1000 mb 18.8N 70.0W Santo Domingo 8/17/ 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/ UTC 70 kt/NE-S 994 mb 24.0N 82.5W "Manhattan" 8/19/ UTC 60 kt/NE-SE ???? mb 24.8N 83.0W "Arbutus" 8/20/ UTC 70 kt/E 999 mb 28.4N 96.8W Indianola 8/20/ UTC ? kt/?? 971 mb 29.6N 98.5W San Antonio 1886/05 (Center positions): Date Time Location Source 8/20/ 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 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 UTC 26.5N 93.3W 280 deg 12 kt 13 mph 22 kph 110 kt 130 mph 210 kph -- mb Major Hurricane - Category 3 August 20 0 UTC 26.8N 94.5W 285 deg 11 kt 12 mph 20 kph 120 kt 140 mph 230 kph -- mb Major Hurricane - Category 4 August 20 6 UTC 27.4N 95.6W 300 deg 11 kt 12 mph 20 kph 130 kt 150 mph 250 kph -- mb Major Hurricane - Category 4 August 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 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 6 UTC 30.8N 99.3W 325 deg 13 kt 14 mph 24 kph 50 kt 60 mph 90 kph -- mb Tropical Storm August UTC 32.0N 100.0W 335 deg 13 kt 14 mph 24 kph 35 kt 40 mph 60 kph -- mb Tropical Storm August 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/ Z 28.0N 96.6W 135kt 4 15nmi mb 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 ( ) of the material and then proceeded through storm 5 (becoming 6) of 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 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 Negative bias errors indicate an underestimation of the true intensity. _________________________________________________________________________ SituationDatesPositionIntensity ErrorIntensity Error Error(absolute)(bias) _________________________________________________________________________ Open ocean nmi/220 km25 kt/13 m s kt/-8 m s nmi/185 km20 kt/10 m s kt/-5 m s -1 Landfall in nmi/220 km25 kt/13 m s kt/-8 m s -1 unsettled area nmi/185 km20 kt/10 m s kt/-5 m s -1 Landfall at nmi/110 km15 kt/8 m s -1 0 kt/0 m s -1 settled area nmi/110 km12 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: #/Date Time Lat Lon Max Saffir- Storm Central States Winds Simpson Surge Pressure Affected 5-8/20/ Z 28.1N 96.8W 135kt 4 15' 925mb BTX4 1-8/10/1856$ 1800Z 29.2N 91.1W 130kt '% 934mb LA4 1-9/9/ Z 29.1N 95.1W 125kt 4 20'%936mb CTX /2/ Z 29.3N 89.8W 115kt mb LA4 7-10/2/ Z 30.9N 81.4W 115kt 4 16' 938mbGA4,DFL2 6-9/16/1855$ 0300Z 29.2N 89.5W 110kt '% (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 (950mb) LA3 2-8/13/1880# 0100Z 25.8N 97.0W 110kt mb ATX3 3-8/16/1888$ 1900Z 25.8N 80.1W 110kt 3 14'% (945mb) CFL3,BFL1 4-9/29/ Z 29.2N 83.1W 110kt mb AFL3,DFL3,GA2,SC1,NC1,VA /12/ Z 29.8N 93.5W 105kt 3 12'% (955mb) LA3,CTX2 9-10/13/ Z 33.0N 79.5W 105kt 3 14'% 955mb SC3,NC2,VA1 5-10/9/ Z 30.2N 85.5W 105kt (955mb) AFL3,GA1 3-8/18/ Z 35.2N 75.8W 105kt (945mb) NC3 8-10/18/ Z 24.7N 81.1W 105kt mb BFL3,CFL3 8-9/21/ Z 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/ Z 30.2N 88.6W 100kt 3 12'% 961mb AL3,MS3,LA2,AFL1 2-9/8/ Z 31.7N 81.1W 100kt mb GA3,SC2,DFL1 6-9/8/ Z 41.4N 71.7W 100kt 3 8'% 965mb RI3,MA3,CT1 3-8/17/1871$ 0200Z 27.1N 80.2W 100kt mb CFL3,DFL1,AFL1 5-10/7/1873$ 0100Z 26.5N 82.2W 100kt 3 14'% 959mb BFL3,CFL2,DFL1 3-9/16/ Z 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/ Z 34.7N 76.7W 100kt 3 7' 971mb NC3,VA2 2-9/10/ Z 30.4N 86.8W 100kt mb AFL3,AL1 2-8/25/ Z 32.2N 80.7W 100kt (953mb) SC3,NC2,GA1,DFL1 6-8/28/ Z 31.7N 81.1W 100kt ' 954mb GA3,SC3,NC1,DFL1 4-7/21/ Z 28.9N 95.3W 100kt 3 10'% 959mb CTX /11/ Z 24.7N 81.0W 100kt mb BFL3,CFL3

Longest lived hurricane on record

Four Hurricanes Simultaneously

U.S. Deadliest Hurricanes of the 19 th Century

Busiest U.S. Hurricane Season on Record

Changes to U.S. Hurricanes 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 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 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 No U.S. hurricanes 3-7/31/1908 NC1 NC1 No change 2-6/29/1909 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 Florid 3-9/14/1910 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 Major Hurricanes In Georgia

Atlantic Hurricane Re-Analysis Project 1.Re-analysis results for 1851 to 1910 a.Overview and HighlightsOverview and Highlights b.DocumentationDocumentation c.DataData 2. Hurricane Andrew's UpgradeHurricane Andrew's Upgrade 3. Books by Jose' Fernandez PartagasBooks by Jose' Fernandez Partagas Picture from: "Florida's Hurricane History", by Jay Barnes through 1940 being re-analyzed currently (working with William Bredemeyer, Steve Feuer, John Gamache and Lenworth Woolcock)

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RECON FLIGHT-LEVEL WINDS HURRICANE GEORGES 9/20/ Z 105 kt 90 kt 95 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 SCHEMATIC AIRCRAFT TRACK DROPSONDE TRAJECTORY 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 radar 145 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)

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 provided Results thus far: – Example: The 1886 Indianola Hurricane – 1851 to 1910 – Hurricane Andrew The Atlantic Hurricane Database Re-analysis Project The Atlantic Hurricane Database 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 Mode Local Correlation of SST versus REOF Mestas-Nunez and Enfield (1999)

WHAT IS THE INTENSITY OF A TROPICAL 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 technique Aircraft 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)

Distance as a Function of RMW MBL to 700mb Ratio Step 1: Flight Level to a Mean Boundary Layer (0 to 500m) Dunion, Landsea, Houston and Powell (2002); Dunion and Powell (2002)

MBL Wind Speed (ms -1 ) MBL Wind Speed (mph) Surface Wind Speed / MBL Wind Speed 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’s Storm Surge And SLOSH Runs

Structural Damage Surveys of Hurricane Andrew