1. Class #18: Friday, October 8
Chapter 8
Tropical Cyclones
Class #18 Friday, October 8, 2010

2. Review sheet for test #2 Test is on Wednesday, October 13
Test covers chapters 6, 7, 8 except for the material in boxes 6.1 (p.162), 6.2 (pp ), 6.3 (pp ), 7.1 (p.196), and 7.2 (p.204).
Format of the test will be similar to test #1
Class #18 Friday, October 8, 2010

3. Fig. 8-29, p. 235

4. More about the life cycle of tropical cyclones
Some go on to become extratropical cyclones in middle latitudes
In the Western Pacific Ocean, an occasional typhoon will go on to become a supertyphoon. These have sustained winds > 150 miles per hour
A widening eye usually indicates a weakening of the storm
Class #18 Friday, October 8, 2010

5. More about the life cycle of a tropical cyclone
On a day to day basis, the intensity of tropical cyclones is influenced by the sea surface temperatures it encounters.
The hurricane season of 2005 broke many records for tropical cyclones—27 named storms in the North Atlantic
Class #18 Friday, October 8, 2010

6. Fig. 8-30, p. 236

7. Fig. 8-31, p. 237

8. How hurricanes cause destruction
Winds: hurricanes are classified as to wind damage using the Saffir-Simpson scale from 1 (weakest) to 5 (strongest)
Hurricanes can contain “mini-swirls” that are tornado-sized with even stronger winds than the main hurricane
Class #18 Friday, October 8, 2010

9. Fig. 8-32, p. 239

10. Table 8-3, p. 240

11. How hurricanes cause destruction
The storm surge is the process of wind-induced seawater flooding
Causes 90% of hurricane deaths
Worst at high tide (new and full moon)
Worst with strong winds
Worst with lowest sea-level pressure
Worst with low-lying land
Depends on coastal and underwater shape
Class #18 Friday, October 8, 2010

12. How hurricanes cause destruction
Rainwater causes flooding
From more deaths were caused by flooding than other types of hazards in hurricanes
Massive flooding can occur with even weak tropical cyclones or tropical storms
Hurricane rains have some beneficial effects
Class #18 Friday, October 8, 2010

13. Fig. 8-33, p. 241

14. How hurricanes cause destruction
Flooding from tropical storm Allison in June 2001 killed at least 20 people and damaged houses with costs near $5 billion
Allison caused rain in every Gulf and Atlantic state from Texas to Maine
Allison caused nearly 36 inches of rain in Houston, TX
Class #18 Friday, October 8, 2010

15. Fig. 8-34, p. 242

16. Forecasting and tracking hurricanes
The story of Bryan Norcross
Broadcast weather information during hurricane Andrew in Florida in 1992
Andrew was a category 5 hurricane
Norcross remained on the air when many of the other stations were off the air
He broadcast forecasts and valuable information about safety in hurricanes
Class #18 Friday, October 8, 2010

17. Box 8-3, p. 243

18. Box 8-3, p. 243

19. Flooding in Hurricane Hugo
Fig. 8-35, p. 244

20. Fig. 8-36, p. 245

21. Fig. 8-37, p. 245

22. Fig. 8-38, p. 246

23. Long-term forecasting of hurricanes
These forecasts are less than perfect
They rely heavily on the cycles of El Niño and La Niño for forecasting in the North Atlantic
Class #18 Friday, October 8, 2010

24. Fig. 8-39, p. 247