Hurricane Case Studies

1. Hurricane Case Studies

2. Outline • North Atlantic • Caribbean • Gulf of Mexico • Atlantic Coast • Pacific • Bangladesh

3. North Atlantic-Caribbean-Gulf of Mexico • ~4-20 tropical storms/hurricanes each year • Tend to form in late summer (highest sea temps) # hurricanes 1931-1980

4. North Atlantic-Caribbean-Gulf of Mexico

5. North Atlantic-Caribbean-Gulf of Mexico • 2 main locations for origin • Western Africa (Cape Verde type) • Caribbean sea

6. Cape Verde Type • Start at low pressure systems in western Africa, hit warm water off coast

7. Cape Verde Type • Strengthen over warm water, move W/NW because of trade winds, Coriolis force • Bermuda High: commonly observed pressure system affects path • Small: storms go north • Big: can push storms into Florida, up East Coast

9. Example: Andrew 1992 • Most destructive (costly) in U.S. history • $30 billion damage • 3rd strongest in 20th century

10. Andrew 1992 • Hit S. Florida first • 33 dead • 80,000 buildings destroyed • Trees, cars demolished • Moved into Gulf of Mexico • Picked up strength with warm water • Hit LA • 15 dead, significant environmental impacts • Heavy rain in MS

11. Radar image at landfall Time lapse satellite image over 3 days of Andrew moving west to east

13. Caribbean Sea • Form in very warm water • Convergence zone of trade winds at equator • Important because convergence means low pressure, tropical depression can form

14. Example: Mitch 1998

15. Mitch 1998 • Began in Caribbean Sea • Formed quickly to Category 5 hurricane • Stayed that way for 33 hours • Headed towards Central America, but stalled • Stayed offshore for 2 days, weakened • Good: didn’t hit coast of Honduras with full force • Bad: dumped 2-6 ft of rain

16. Results of Mitch 1998 • Honduras • 6500 fatalities • 20% population homeless • 60% roads/bridges destroyed • Nicaragua • 3800 fatalities • Lahars from flooding of volcanic lake • Moved out to Gulf, hit S. Florida on to north of England • Total: 11,000 fatalities

17. Flooding and road damage in Nicaragua

18. Gulf of Mexico Hurricanes • Along coast: low elevation land • Along TX coastline, almost 6000 mi2 is less than 20 ft above sea level • Significant problem for storm surges

20. Galveston, 1900 • Deadliest natural disaster in U.S. history • Town on low-lying island in front of bay • Category 4 storm hit; flooded island several ft • Storm waves, wind destroyed 3600 buildings • Bridges washed out • Over 7000 fatalities (roughly 1 in 6 residents)

22. Atlantic Coast - Hugo 1989 • Category 4 storm • 17 ft surge in Ft. Sumter, SC • Moved into NC, WV, OH, PA, NY, Canada as rain • Only 11 fatalities

24. 2004 Events • 15 tropical storms in North Atlantic during the 2004 hurricane season. • Nine of these became hurricanes • six becoming major hurricanes (Category 3+) • Ivan strongest (Category 5)

25. 2004 Storms • http://www.cnn.com/SPECIALS/2004/hurricanes/interactive/hurricane.paths/index.html 2004 was predicted to be an “active” season with 12-15 tropical storms FEMA distributed a record $4.85 billion in hurricane relief in 2004 4 hurricanes hit Florida, a record for the state 1 in 5 homes in Florida damaged 117 fatalities in FL alone

26. Hurricane Charley • Landfall near Ft. Myers, FL as Cat. 4 storm on Aug 13th • 16 fatalties, 2 million lost power • Damage likely ~$10 billion • Made 2nd landfall along S.Carolina • Maintained tropical storm force winds through New England (few inches of rain there)

27. Charley

28. Hurricane Frances • Reached Cat. 4 status over Bahamas (Aug 28) • Hit east coast of Florida as Cat. 2 (Sept5), traveled over state, made 2nd landfall on panhandle as tropical storm • Traveled north, dropping heavy rains • Quebec got over 8 inches of rain! • Also spawned 117 tornadoes • 23 fatalities

30. Hurricane Frances

31. Hurricane Ivan • Category 5 storm over Grenada, Cayman Islands (Sept 7-9) • Landfall as Cat. 3 in Alabama • Wacky path - went northeast, then back southwest to cross Florida, Gulf of Mexico on Sept 21 (strengthened back to tropical storm), 2nd landfall in LA on 24th • Significant rain, flooding (U.S. deaths ~50, more across the Caribbean)

32. Hurricane Ivan

33. Hurricane Jeanne • Formed on Sept. 13, weakened by Sept. 18th, strengthened by 19th and headed out to sea, turned back towards U.S. by 24th • Significant fatalities in Haiti (over 3000) from flooding and mudslides • Landfall in U.S. in FL as Cat. 3 on Sept 26th (almost same location as Frances) • Tracked into mid-Atlantic states • Flooding, 10 fatalities in US

35. Pacific Coast • ~15% of events form in Pacific offshore Mexico, Guatemala, El Salvador • Less hit land than Atlantic hurricanes • Why? • Trade winds push westward, away from land • Colder water in Pacific reduces potential (California current brings cold water from Alaska)

36. Pauline, 1997 • Category 4 storm • Main problem: rain caused flooding and debris flows

37. Iniki, 1992 • Category 4 storm hit Kauai, HI • Significant building damage $2 billion

38. Bangladesh • Cyclones in this area: Most deadly events • Densely populated area on low-lying deltas • 35% of country is < 20 ft elevation • In average year, 20% is flooded • Cyclones are common • ~5/year

40. Bangladesh • 1970 ~category 5 storm 400,000 fatalities • 1991 140,000 fatalities, 10 million homeless • Population expected to double in next 30 years!

41. Next Time • Coastal Hazards