WHY IKE A CATEGORY 2 HURRICANE WHY IKE A CATEGORY 2 HURRICANE WAS SO DEVASTATING WAS SO DEVASTATING

THE FREEMAN HURRICANE DAMAGE THE FREEMAN HURRICANE DAMAGE POTENTIAL SCALE POTENTIAL SCALE 2011 Hurricane Outlook2011 Hurricane Outlook

Jill F. Hasling, PresidentJill F. Hasling, President

Certified Consulting MeteorologistCertified Consulting Meteorologist

Weather Research CenterWeather Research Center

5104 Caroline St. Houston, Texas 77004 5104 Caroline St. Houston, Texas 77004

www.wxresearch.comwww.wxresearch.com

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Who We Are

The John C. Freeman Weather Forecast Training and Operations Center

WRC Meteorologists

The John C. Freeman Weather Forecast Training and Operations Center

• World Wide Marine Weather Forecasts

• Hurricane/Tropical Cyclone Predictions

• Environmental Studies• Weather Forensics• Long Range Weather

Forecasts• Development of Forecast

Models

Significant Projects:• Established the Nation’s First Weather Museum• Texas First Tornado Warning Network• 1st Storm Tide Prediction System (Bathystrophic Storm Tide)

Hurricane Ivan – 2004 Hurricanes Katrina and Rita – 2005 and Hurricane Ike 2008 would make one believe that hurricanes are getting larger and stronger.

Hurricane Ivan – 2004 Hurricanes Katrina and Rita – 2005 and Hurricane Ike 2008 would make one believe that hurricanes are getting larger and stronger.

Is this due to climate change or is human’s understanding of hurricanes changing?

Atlantic Basin Category 5 Hurricanes32 Category 5 Hurricanes have occurred since 1900

Lowest Pressure –

Hurricane Wilma 2005 - 882 mbs

Highest maximum sustained winds –

Hurricane Allen 1980 - 165 Knots

Most Category 5 Hurricanes per season

2005 – (Four) – Emily, Katrina, Rita and Wilma

2007 – (Two) – Dean and Felix

1961 – (Two) – Carla and Hattie

1960 – (Two) – Donna and Ethel

NOTABLE CATEGORY 5 GOM LEASE HURRICANESNOTABLE CATEGORY 5 GOM LEASE HURRICANES

165 kts 165 kts Hurricane Camille Hurricane Camille 1969 1969

155 kts155 kts Hurricane Allen Hurricane Allen 19801980

155 kts155 kts Hurricane RitaHurricane Rita 20052005

150 kts150 kts Hurricane Carla Hurricane Carla 19611961

150 kts150 kts Hurricane KatrinaHurricane Katrina 20052005

140 kts140 kts Hurricane BeulahHurricane Beulah 19671967

140 kts140 kts Hurricane EthelHurricane Ethel 19601960

135 kts135 kts Hurricane BetsyHurricane Betsy 19651965

Atlantic Ocean 1900-2008

0

5

10

15

20

25

30

1900 1920 1940 1960 1980 2000

Year

Nu

mb

er

of

Sto

rms

PLOT OF THE NUMBER OF KNOWN TROPICAL CYCLONES 1900-2008

Seems to indicate that the number of cyclones is increasing?

Problems with Using Historical Tropical Cyclone Data

• 1851-1914 – Landfall observations and Ship

Reports • 1915-1945 – Density of Ship Reports

expanded after the Panama Canal opened

• 1946-1965 – Ship traffic expands after WWII

• 1966 – Continuous monitoring by satellite begins• 2002 – QuikScat wind vectors – Improved

satellite observations

Atlantic ship traffic changes

Vecchi and Knutson (2008)

Radar in 1957 versus Doppler Radar in 2005

Open AtlanticOcean Differences

1933 Hurricane Season

2005 Hurricane Season

Data problem: Hurricanes were hardly detected over open ocean before the era of aircraft reconnaissance (mid-1940s) and satellite

technology (mid-1960s).

Landsea (2007, Eos)

Estimated Number of “Missed” Tropical Storms and Hurricanes of Medium to Long Duration

3 per year in 1880s

2 per year in 1900s

<1 per year in 1950s

Tropical Storm and Hurricane Numbers –Upward Trend Gone After Adding in “Missed”

and Removing Very Short-Lived Cyclones

98

Size Matters!

Hurricane Wind Fields for Past GOM Hurricanes

Radius of Hurricane Force Winds

70

50

60

100

60

50 50

8075

70

60 60

50 50 50

60 60

25

70

5045

60

50

40

109

50

60

100

40

30

50

75

40

50

60

50

75 75

100

40

125

60

35

45

90 90

75

20

60

110

0

20

40

60

80

100

120

140

1886

1886

1900

1906

1909

1909

1910

1915

1915

1916

1916

1916

1919

1926

1932

1933

1942

1943

1945

1947

1949

1953

1957

1960

1961

1964

1965

1967

1969

1970

1974

1975

1977

1979

1980

1983

1985

1985

1988

1992

1995

1998

1999

2002

2004

2005

2005

2008

2008

2008

Radius of Hurricane Force Winds

There were 50 Gulf of Mexico Oil Lease Hurricanes where the size of the hurricane wind field could be estimated.

10 of these hurricanes had a radius of maximum sustained winds of 50 nautical miles or less.

23 of the hurricanes had a radius greater than 50 nautical miles but less than 61 nautical miles.

17 of the hurricanes had a radius of hurricane force winds greater than 69 nautical miles.

WHY SIZE MATTERS!

The distance the wind blows over a body of water [fetch] and the duration of the high winds, the higher the waves can become.

Sig Wave by Fetch for maximum sustained winds of 34, 50, 64 and 95 kt

0

20

40

60

80

100

120

140

0 50 100 150 200 250 300 350 400 450 500 550 600

Fetch n. mi

Sig

Wav

e F

eet

Gulf of Mexico Category 3, 4 & 5

Hurricanes

The result of this research is the development of

The Freeman/Hasling Hurricane Damage Potential Scale

[Freeman/Hasling - HDP Scale]

The Freeman/Hasling Hurricane Damage Potential Scale is based on:

• Maximum Sustained Wind• Radius of Hurricane Force Winds• Central Pressure• Area of Significant Wave > 34 Feet• Hurricane Track• Hurricane Speed• Duration of Hurricane Force Winds• Exposed Offshore Properties

Freeman/Hasling Hurricane Damage Potential Scale

R64 <=30 >30 >=45 >=60 >=80

Saffir/Simpson          

1 1 1 1 4 5

2 1 1 1 5 5

3 1 1 1 5 5

4 1 1 2 5 5

5 1 2 3 5 5Freeman/Hasling HDP Scale

1 2 3 4 5

HDP Percent 2% 4% 6% 8% 10%

Are Humans at Fault for More and Stronger Offshore Hurricanes?

Yes

In Summary, to answer the questions:

Have there been similar Gulf of Mexico hurricanes to Ivan 2004, Katrina 2005, Rita 2005 and Ike

2008?

Yes the hurricanes in the 1960s, 1910s, and 1880s. In the 1960s,

there were four Category 5 hurricanes over the Gulf leases.

If the Gulf of Mexico hurricanes are sorted by decades, are there differences in the number and

strength of hurricanes by decade?

Yes, for two decades you will have an active period of major

hurricanes followed by a decade of very few major hurricanes over the

Gulf leases.

How would the early Gulf of Mexico hurricanes impact the Gulf oil leases

today?

The 1910s would have been very devastating to the properties in the Gulf

of Mexico with five Category 5 hurricanes. There were two Category 4 hurricanes in 1915, one that went over

the eastern oil leases and one that went through the western oil leases.

Were the hurricanes of the 1960s smaller and weaker or was the

exposure offshore less dense?

The exposure of the properties to the hurricanes of the 1960s was less dense. Hurricane Carla in 1961 was

a Category 5 hurricane offshore with a very large wind field. At the time,

there were only 517 offshore properties.

How have humans observed hurricanes throughout history?

How humans have observed hurricanes has changed through

the years as technology improves. This has impacted the number of

observed hurricanes and the hurricane climatology.

What part do improved observations play in the size and strength of

hurricanes?

Humans are responsible for the implied increase in hurricane frequency and strengths by

developing the improved observing tools.

Weather Research Center

Houston, Texas

www.wxresearch.com

wrc@wxresearch.org