1. Atlantic Basin Seasonal Hurricane Prediction Phil Klotzbach Department of Atmospheric Science Colorado State University National Hurricane Conference March 31, 2015

2. Outline Introduction Atlantic Basin Multi-Decadal Hurricane Variability Recent Downturn in US Landfalling Hurricane Activity Tropical Cyclones and Climate Change 2014 Atlantic Basin Seasonal Forecast Verification 2015 Atlantic Basin Seasonal Outlook

4. “It's tough to make predictions, especially about the future” HOWEVER… “You can see a lot by looking” Yogi Berra

5. August – October SSTs: Ten Most Active – Ten Least Active Atlantic Hurricane Seasons Since 1950

6. b – La Niña a – El Niño

12. THC (or AMO) STRONG THC (or AMO) WEAK

13. 12 3 H H Courtesy of John Marshall (MIT)

14. 1860 1900 1940 1980 2020 Goldenberg et al. (2001)

19. 1915-1964 50 YEARS 23 MH 65 54 4450 60 59 60 54 55 54 55 45 47 49 48 38 35 29 26 28 33 1965-2014 50 YEARS 9 MH 89 85 04 05 04 92 96 40% as frequent U.S. MAJOR HURRICANE IMPACTS 21 19 65 93

23. 1926 2014 1926 Great Miami Hurricane - $165 Billion Insured Damage

26. Global ACE (1970- February 2015)

27. 2014 Atlantic Hurricane Season Forecast Verification

28. ATLANTIC BASIN SEASONAL HURRICANE FORECASTS FOR 2014 Forecast Parameter and 1981- 2010 Median (in parentheses) 10 April 2014 Update 2 June 2014 Update 1 July 2014 Update 31 July 2014 Observed 2014 Total % of 1981- 2010 Median Named Storms (NS) (12.0)910 867% Named Storm Days (NSD) (60.1)3540 3558% Hurricanes (H) (6.5)3444692% Hurricane Days (HD) (21.3)1215 17.7583% Major Hurricanes (MH) (2.0)11112100% Major Hurricane Days (MHD) (3.9)23333.7596% Accumulated Cyclone Energy (ACE) (92) 5565 6773% Net Tropical Cyclone Activity (NTC) (103%) 6070 8280%

30. Relative Humidity Anomalies (600 mb) from mid-Aug to mid- Oct

32. 2015 Atlantic Hurricane Season Initial Outlook

33. Current Global Sea Surface Temperature Anomaly Map

34. August – October SSTs: Ten Most Active – Ten Least Active Atlantic Hurricane Seasons Since 1950

38. El Niño Neutral

39. El Niño La Niña

43. EQ. New April Forecast Predictors March SLP Jan-Mar SST ` ECMWF SST Forecast 1`1` 4`4` 3`3` February- March SLP 2`2`

45. 20 TH CENTURY CLIMATOLOGICAL PROBABILITES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL IN EACH OF THE FOLLOWING AREAS 1)Entire U.S. coastline – 52% 2)U.S. East Coast including Peninsula Florida – 2)U.S. East Coast including Peninsula Florida – 31% 3)Gulf Coast from the Florida Panhandle westward to Brownsville – 30% 4)Caribbean (10-20°N, 60-88°W) – 42% 1)Entire U.S. coastline – 52% 2)U.S. East Coast including Peninsula Florida – 2)U.S. East Coast including Peninsula Florida – 31% 3)Gulf Coast from the Florida Panhandle westward to Brownsville – 30% 4)Caribbean (10-20°N, 60-88°W) – 42%

46. Landfalling Hurricane Web Application Currently Available at the following URL: In partnership with the GeoGraphics Laboratory – Bridgewater State University, Bridgewater MA http://www.e-transit.org/hurricane

47. 20 th Century Climatological Probabilities State Hurricane Impact Prob. MH Impact Prob. Florida51%21% Louisiana30%12% Massachusetts7%2% Mississippi11%4% New York 8%3% North Carolina 22%8% Texas33%12%

48. Country/Island Hurricane within 100 Miles MH within 100 Miles The Bahamas 51%30% Cuba52%28% Haiti27%13% Jamaica25%11% Mexico57%23% Puerto Rico 29%13% US Virgin Islands 30%12% 20 th Century Climatological Probabilities

49. Date 9 April 1 June 1 July 3 Aug SeasonalForecastXXXX 2015 Forecast Schedule 2015 Forecast Schedule

50. Arago’s Admonition: “Never, no matter what may be the progress of science, will honest scientific men who have regard for their reputations venture to predict the weather.” Arago’s Admonition: “Never, no matter what may be the progress of science, will honest scientific men who have regard for their reputations venture to predict the weather.”

51. Contact Info: Phil Klotzbach Email: philk@atmos.colostate.edu Web: http://tropical.atmos.colostate.edu Twitter: @philklotzbach Facebook: CSU Tropical Meteorology Project Contact Info: Phil Klotzbach Email: philk@atmos.colostate.edu Web: http://tropical.atmos.colostate.edu Twitter: @philklotzbach Facebook: CSU Tropical Meteorology Project