1. This work is supported by a National Science Foundation (NSF) collaboration between the Directorates for Education and Human Resources (EHR) and Geociences (GEO) under grant DUE - 1125331 Comparing Hurricanes and Hurricane Seasons

2. Saffir-Simpson Scale What is a hurricane? What 4 conditions are necessary for hurricane formation What happens as hurricanes approach land? Based on wind speed: Hurricanes that are Category 3 or higher (>111 knots) are called major hurricanes.

3. ACE =10 -4 Σ(maximum wind speed in knots) 2 maximum sustained winds every 6 hours Accumulated Cyclone Energy

4. Example: Irene (2011) daytimemax sust winds (kt)ACE (10^-4 kt^2) 9/8/110450.2025 9/8/11600500.25 9/8/111200550.3025 9/8/111800650.4225 9/9/110650.4225 9/9/11600550.3025 9/9/111200500.25 9/9/111800450.2025 9/10/110450.2025 9/10/11600450.2025 9/10/111200500.25 9/10/111800550.3025 9/11/110550.3025 9/11/11600500.25 9/11/111200400.16 9/11/111800350.1225 total4.15

5. Example: 2011 Total ACE (10 4 kt²) — Storm: 127.0Katia112.22Emily 218.8Irene121.88Arlene 318.7Ophelia131.85Gert 415.9Philippe141.79Lee 510.1Rina151.62Don 69.17Maria161.53Harvey 74.31Nate 17 0.848Unnamed 83.75Sean0.848Jose 93.28Bret190.283Franklin 102.31Cindy Total: 126 Is a seasonal total ACE of 126 above normal? Below normal? Normal?

6. ACE Season Totals What was last season’s ACE total? http://www.srh.noaa.gov/bro/?n=2012event_hurricaneseasonwrap Season typeACE (x 10 4 kt 2) Above normalAbove 150 Near normal100-150 Below normalBelow 100

7. Seasonal Outlooks There is great interest in trying to predict: – How many hurricanes, major hurricanes? WHY? General awareness/preparedness Some predictions about climate are useful for deciding what crops to plant HOWEVER — we cannot yet predict specific hurricanes more than a few days in advance

9. We are currently in a high-activity era More total storms per year More big storms per year And more energy released by all the hurricanes combined in a year (ACE)

11. The latest...

12. Looking at the most recent hurricane season outlook for the Atlantic Ocean: http://www.cpc.ncep.noaa.gov/products/outl ooks/ http://www.cpc.ncep.noaa.gov/products/outl ooks/ What implications can you imagine for this outlook (above-normal, normal, or below- normal) for 1.a farmer in Georgia? 2.a governor in New Jersey? 3.your own life? Plant more drought-resistant or water-loving crops? Allocate funds for education and evacuation? Cut tree limbs near house? Restock emergency kit?

13. Summary How big is a hurricane? – Saffir-Simpson scale – ACE Index calculation Multi-decadal cycles (high/low activity eras) Seasonal outlooks and applications to society

14. References and Reuse Slide 4. Data in public domain. http://en.wikipedia.org/wiki/2011_Atlantic_hurricane_season Slides 4 and 5. Data in public domain... Can be updated for different years and hurricanes: http://rammb.cira.colostate.edu/products/tc_realtime/ Slide 6. Screenshot from NOAA. Website in public domain. http://www.srh.noaa.gov/bro/?n=2012event_hurricaneseasonwrap Slide 8. Screenshot from NOAA. Website in public domain. http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane2012/August/figure3. gif http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane2012/August/figure3. gif Slide 10. Screenshot from NOAA. Website in public domain. http://www.cpc.ncep.noaa.gov/products/outlooks/figure2.gif Slide 11. Screenshot from NOAA. Website in public domain. http://www.nhc.noaa.gov/ Slide 12 refers to Hurricane Outlooks at: http://www.cpc.ncep.noaa.gov/products/outlooks/