1. HURRICANE STRUCTURE Dr. Richard M. Yablonsky University of Rhode Island/GSO Hurricane Webinar Series 2012 28 February 2012, 7:00pm EST

2. WHAT IS THIS??? Image courtesy of http://www.andovernet.com/ < 1 mile

3. WHAT IS THIS??? Image courtesy of http://www.andovernet.com/ The Andover, KS TORNADO of April 26, 1991 (Wind ≈ 250 mph) This is NOT a hurricane!!! This is NOT a hurricane!!! < 1 mile

4. WHAT IS THIS??? Image courtesy of http://www.chaseday.com/ < 1 mile ~ 10 miles

5. WHAT IS THIS??? Image courtesy of http://www.chaseday.com/ A thunderstorm near Ardmore, OK This is NOT a hurricane! < 1 mile ~ 10 miles

6. OK Rich… so you have lectured us on what a hurricane IS NOT. Please stop teasing and tell us what a hurricane IS!

7. Definitions from United States National Hurricane Center Hurricane: “A tropical cyclone in which the maximum sustained surface wind is 74 mph or more” (NHC).OK, but what is a tropical cyclone?

8. Definitions from United States National Hurricane Center Hurricane: “A tropical cyclone in which the maximum sustained surface wind is 74 mph or more” (NHC).OK, but what is a tropical cyclone? Tropical cyclone: “A warm-core, non-frontal, synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well- defined center” (NHC).WHAT??? 

9. Hurricane Ivan on September 9, 2004 ~ 250 miles Image courtesy of NOAA

10. Hurricane Ivan on September 9, 2004 ~ 250 miles Image courtesy of NOAA A thunderstorm in one of Ivan’s spiral bands

11. Hurricane Ivan on September 9, 2004 ~ 250 miles Eye (No Wind) Image courtesy of NOAA A thunderstorm in one of Ivan’s spiral bands

12. Hurricane Ivan on September 9, 2004 ~ 250 miles Eyewall: Region of strongest winds Eye (No Wind) Image courtesy of NOAA A thunderstorm in one of Ivan’s spiral bands

13. What about SIZE ? Courtesy of Brian Kabat US Air Force Academy 100 mi SIZE ≠ INTENSITY!

14. What about SIZE ? Courtesy of Brian Kabat US Air Force Academy 100 mi 200 mi SIZE ≠ INTENSITY!

15. 09/13/04 1200Z 09L IVAN 09/13/04 1315Z GOES - 12 VIS What about SIZE ? Courtesy of Brian Kabat US Air Force Academy 100 mi 250 mi 200 mi SIZE ≠ INTENSITY!

16. 09/13/04 1200Z 09L IVAN 09/13/04 1315Z GOES - 12 VIS What about SIZE ? Courtesy of Brian Kabat US Air Force Academy 100 mi 250 mi 200 mi 150 mph (Category 4) 140 mph (Category 4) 160 mph (Category 5) SIZE ≠ INTENSITY!

17. Largest & Smallest Tropical Cyclones

18. What about eyes? Here is Wilma…

19. And here is Isabel!

20. Vertical slice through a hurricane

21. Wind speed distribution

22. Hurricane’s Secondary Circulation

23. Convection in the Atmosphere COLD COOL WARM Image courtesy of http://home.comcast.net/~j2jensen/

24. Convection in the Atmosphere COLD COOL WARM HOT Image courtesy of http://home.comcast.net/~j2jensen/

25. Convection in the Atmosphere COLD COOL WARM HOT COLD WARM Image courtesy of http://www.photohome.com/ Image courtesy of http://home.comcast.net/~j2jensen/ The hot air parcel rises… just like in a hot air balloon!

26. Hurricanes are fueled by the ocean URI team focus: Understanding & modeling hurricane-ocean interaction

27. Tropical vs. Extratropical Cyclones

28. Extratropical Transition

29. Definitions from United States National Hurricane Center Hurricane: “A tropical cyclone in which the maximum sustained surface wind is 74 mph or more” (NHC).Rich, you said that already! Tropical cyclone: “A warm-core, non-frontal, synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well- defined center” (NHC).I think I get it now!

30. Hurricanes: Science and Society Learn more at: www.hurricanescience.org