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NOAA Press Release: Immediate Distribution 2006 hurricane season. National Weather Service To Give Hurricanes Full Names May4, 2006 | the ONION: Issue 42•09 SILVER SPRING, MD—
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NOAA Press Release: Immediate Distribution 2006 hurricane season National Weather Service To Give Hurricanes Full Names May4, 2006 | the ONION: Issue 42•09SILVER SPRING, MD— The National Weather Service announced Friday that, in response to the increasing number of hurricanes, it is revising its naming system. "The hundreds of hurricanes we expect in the North Atlantic in 2006 will receive both proper and surnames," Max Mayfield of the weather service said. "In fact, tropical storms Alberto Fergus, Beverly Stenwick-Brown, and Chris Stubbs Jr. have already received names under the new system." After all possible first and last names are exhausted, storms will be given titles, beginning with Hurricane Assistant Accounts Manager Alexander Epps, CPA.
Surface Temperature Variability Volcano Solar Sulfate There is no known natural forcing mechanism that can explain the surface temperature increases since 1960 (Meehl et al 2004, 2006) Notice the warm 1940-50 period in the “natural cycle” Ozone
Strong apparent relationship between Atlantic storms and sea-surface temperature (1910-2005)
Hurricane season SST in tropical ocean basins • North Atlantic Ocean (ATL) • East Pacific Ocean (EPAC) • West Pacific Ocean (WPAC) • North Indian Ocean (NIO) • Southwest Pacific (SPAC) • South Indian Ocean (SIO) All tropical ocean basins show monotonic increase of SST
Global number of storms and storm days No statistically significant change in number of storms.
Number of hurricanes in tropical basins • Largest decreases occur in WPAC and southern hemisphere. • North Atlantic shows monotonic increase
Change in storm intensity globally Between 1970-1985 and 1985-2005, the number of category 4 and 5 storms has doubled
Change in intensity occurs in severe (3+4+5) as well as in categories (4+5)
Time that a hurricane remains as a category 3, 4 or 5 has increases by 1/2 day across last three decades
N. Atlantic tropical storm season length has increased 4.8 days/decade for past 100 years Gulledge et al., Science, submitted
What do these global changes in hurricane intensity mean for the Gulf and Southeastern states of the US? • High probability that the last decade characteristics will become the base of a new hurricane distribution • 1995-2005 will not the “100-year” decade • Gulf storms such as Dennis, Emily, Katrina, Rita and Wilma may become more the norm
2005 Dennis, Emily, Katrina, Rita, Wilma 5 category 4-5 hurricanes in the Gulf Katrina/Rita/Dennis/ Emily/Rita/Wilma
Why should wind speed be important? Damage by winds goes as: Cat 3 does 170% more damage than Cat 2 Cat 4 does 270% more damage than Cat 2 Cat 5 does 400% more damage than Cat 2
2005 season Five Gulf Category 4-5 storms http://weatherunderground.com/tropical
Consequences of the formation of more storms in the 10-20N region (Cape Verde storms)
During the last decade, an increasing number of storms have developed from atmospheric waves from Africa Increasing sea-surface temperature and long-term changes in their patterns in the equatorial North Atlantic mean that more hurricanes form in the 8-20N latitude band
Equatorial 90% 92% 81% 55% 36% 42% (Data 1945-2004) These are important for the Gulf and the SE US for the following reasons • >85% of all Major hurricanes develop from African waves!!! • Hurricanes developing close to in the equatorial Atlantic impact the Caribbean, Central America, the Gulf and the Gulf states • > 50% of all major hurricanes develop south of 20N
Where and how much the SST increases explains shift in characteristics 9-y Mean SST variations explain 69% of the variance in equatorial (easterly wave) developments.
Impacts of more Gulf storms • Demographic changes towards south and the coast have increased vulnerability of larger percentage of population • Energy industry increasingly vulnerable • Coastal bathymetry conducive to large storm surge • More storm landfalling and moving into southern states
Hurricane Wilma Visible Infrared
But not all tropical cyclones are benign Nov. 17, 1970: Tropical cyclone crossed coast of Bangladesh. High tide and 4-5 m (12-15 ft) storm surge at high tide drowned 300,000 people, 280,000 cattle and destroyed 90,000 boats
Consequences of more Gulf of Mexico land-falling hurricanes for the SE, mid-west and Eastern USA
Impacts of Gulf land-falling hurricanes • Gulf coastal storm surges • Wind damage in coastal regions • Large-scale and intensity precipitation over land often causing severe flooding • Consequences for agriculture (crop damage, water pollution from overflow of feed lot lagoons) • Tornadoes that may be remote to landfalling location
The possibility and consequences of a major land-falling hurricane in coastal Georgia
1995-2005 U.S. Landfalling Hurricanes Legend: Cat 5 - Cat 4 -Cat 3 - Cat 2 - Cat 1 - The Gulf Estimated Impacted Area for Cats 4 through 1 44% of U.S. landfalling hurricanes hit FL
Land-falling hurricanes on Georgia coast extremely rare • No hurricane for over 100 years but a series of devastating landfalling hurricanes created storm surges drowning 1000’s of residents. • Hurricanes were not of high category but extensive shoaling continental shelf allows extensive storm surges. • Georgia coast is considered by FEMA as especially vulnerable to storm surges
100 mph 120 mph 160 mph 140 mph
What can be done? • Plan for at least a continuation of the active period of 1995-2005 • In risk analysis, take into account high probability of considerable greater activity in coming decades • Consider long-term spending (including relocation) to mitigate problems in vulnerable areas. Better to spend $10B/year and lose no lives than $200B every year or so with many deaths cleaning up after future Katrinas. • Better seasonal forecasts and learn how to use them (there is hope!)
