1. Comparing Hurricanes andHurricane SeasonsThis work is supported by a National Science Foundation (NSF) collaboration between theDirectorates for Education and Human Resources (EHR) and Geociences (GEO) under grant DUE - 1125331

2. Saffir-Simpson Scale Based on wind speed: What is a hurricane? What 4 conditions Category are necessary for Maximum hurricane SustainedformationWind Speed (knots) What happens as hurricanes approach land?Hurricane Category 5 157Hurricane Category 4 130156Hurricane Category 3 111129Hurricane Category 2 96110Hurricane Category 1 7495Tropical Storm 3973Tropical Depression 038Hurricanes that are Category 3 or higher (>111 knots) are called major hurricanes. 3. Accumulated Cyclone EnergyACE =10-4(maximum wind speed in knots)2maximum sustained winds every 6 hours 4. Example: Irene (2011)day time max sust winds (kt) ACE (10^-4 kt^2)9/8/11 0 45 0.20259/8/11 600 50 0.259/8/11 1200 55 0.30259/8/11 1800 65 0.42259/9/11 0 65 0.42259/9/11 600 55 0.30259/9/11 1200 50 0.259/9/11 1800 45 0.20259/10/11 0 45 0.20259/10/11 600 45 0.20259/10/11 1200 50 0.259/10/11 1800 55 0.30259/11/11 0 55 0.30259/11/11 600 50 0.259/11/11 1200 40 0.169/11/11 1800 35 0.1225total 4.15 5. Example: 2011 TotalACE (104kt) Storm:1 27.0 Katia 11 2.22 Emily2 18.8 Irene 12 1.88 Arlene3 18.7 Ophelia 13 1.85 Gert4 15.9 Philippe 14 1.79 Lee5 10.1 Rina 15 1.62 Don6 9.17 Maria 16 1.53 Harvey7 4.31 Nate170.848 Unnamed8 3.75 Sean 0.848 Jose9 3.28 Bret 19 0.283 Franklin10 2.31 CindyTotal: 126 Is a seasonal total ACE of 126 abovenormal? Below normal? Normal? 6. ACE Season TotalsSeason type ACE(x 104 kt2)Above normal Above 150Near normal 100-150Below normal Below 100 What was last seasons ACE total? http://www.srh.noaa.gov/bro/?n=2012event_hurricaneseasonwrap 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 fordeciding what crops to plantHOWEVER we cannot yet predict specifichurricanes more than a few days in advance 8. We are currently in a high-activity era More total storms per year More big storms per year And more energy released by all thehurricanes combined in a year (ACE) 9. The latest . . . 10. Looking at the most recent hurricane seasonoutlook for the Atlantic Ocean:http://www.cpc.ncep.noaa.gov/products/outlooks/ What implications can you imagine for thisoutlook (above-normal, normal, or below-normal)for1. a farmer in Georgia?2. a governor in New Jersey?3. your own life?Plant more drought-resistantor water-loving crops?Allocate funds for educationand evacuation?Cut tree limbs near house?Restock emergency kit? 11. 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 12. References and ReuseSlide 4. Data in public domain. http://en.wikipedia.org/wiki/2011_Atlantic_hurricane_seasonSlides 4 and 5. Data in public domain . . . Can be updated for different years andhurricanes: 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_hurricaneseasonwrapSlide 8. Screenshot from NOAA. Website in public domain. http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane2012/August/figure3.gifSlide 10. Screenshot from NOAA. Website in public domain. http://www.cpc.ncep.noaa.gov/products/outlooks/figure2.gifSlide 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/