Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2008 Superensemble Forecasts of Hurricane Track and Intensity Using a Suite of Mesoscale Models Melanie A. Kramer Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES SUPERENSEMBLE FORECASTS OF HURRICANE TRACK AND INTENSITY USING A SUITE OF MESOSCALE MODELS By MELANIE A. KRAMER A Thesis submitted to the Department of Meteorology in partial fulfillment of the requirements for the degree of Master of Science Degree Awarded: Summer Semester, 2008 The members of the Committee approve the Thesis of Melanie A. Kramer defended on May 23, 2008. _________________________ T.N. Krishnamurti Professor Directing Thesis _________________________ Robert Hart Committee Member _________________________ Paul Ruscher Committee Member The Office of Graduate Studies has verified and approved the above named committee members. ii ACKNOWLEDGEMENTS I would like to acknowledge my major professor, Dr. T.N. Krishnamurti, for all of his instruction and guidance. The many meetings with my other committee members, Dr. Robert Hart and Dr. Paul Ruscher, provided new and beneficial insight into different aspects of this project, for which I am most grateful. Their comments helped me to learn a great deal about modeling and kept me interested in studying hurricanes. Thanks to the Krishnamurti lab, specifically Mrinal Biswas, Dr. Sandeep Pattnaik, Dr. Arindam Chakraborty, and Dr. Lydia Stefanova for the countless hours of instruction and assistance in this research process, for which I am greatly indebted. Thank you also to the many who have gone before me helping me in writing, formatting, and getting through. Lastly thank you to all who supported me and helped me to remember that science can and will always be fun. iii TABLE OF CONTENTS List of Tables .................................................................................... vi List of Figures .................................................................................... vii List of Abbreviations............................................................................... xiii Abstract .......................................................................................... xv 1. INTRODUCTION............................................................................... 1 1.1 Background and Thesis Objectives........................................... 1 1.2 Previous Work .......................................................................... 2 1.3 Organization of Thesis.............................................................. 6 2. SUPERENSEMBLE METHODOLOGY ............................................. 8 2.1 History of the Florida State Superensemble ............................. 8 2.2 Description of the Florida State Superensemble....................... 10 2.3 Model Description ..................................................................... 13 2.3.1 WRFA .............................................................................. 14 2.3.2 WRFB .............................................................................. 16 2.3.3 MM5................................................................................. 16 2.3.4 HWRF.............................................................................. 18 2.4 Large Scale Model Description ................................................. 20 2.4.1 OFCI, PERS .................................................................... 21 2.4.2 A90E, A98E, A9UK.......................................................... 22 2.4.3 GFSI ................................................................................ 22 2.4.4 SHF5................................................................................ 22 2.4.5 CLIP, CLP5...................................................................... 23 2.4.6 GFDL ............................................................................... 23 2.4.7 DSHP............................................................................... 26 2.5 Description of FSSE Experiments............................................. 28 3. OVERALL RESULTS AND ERROR METHODOLOGY..................... 32 3.1 Error Calculation Methodology.................................................. 32 3.2 Overall Errors............................................................................ 34 3.3 Discussion ................................................................................ 38 iv 4. YEARLY ERROR RESULTS............................................................. 40 4.1 2004 Errors ............................................................................... 40 4.2 2005 Errors ............................................................................... 45 4.3 2006 Errors ............................................................................... 49 4.4 Discussion ................................................................................ 52 5. INDIVIDUAL STORMS AND MODEL DISCUSSION ........................ 54 5.1 Overview................................................................................... 54 5.2 Hurricane Ivan .......................................................................... 54 5.3 Hurricane Gordon ..................................................................... 62 5.4 Hurricane Helene...................................................................... 67 5.5 Hurricane Isaac......................................................................... 72 5.6 FSSE Mesoscale and Large Scale Model Run Comparisons ... 78 5.7 Limitations of Tropical Cyclone Modeling.................................. 81 6. CONCLUSIONS AND FUTURE WORK............................................ 83 6.1 Conclusions .............................................................................. 83 6.2 Future Work .............................................................................. 86 REFERENCES .................................................................................... 91 BIOGRAPHICAL SKETCH .................................................................... 100 v LIST OF TABLES Table 2.1: ............................................................................................... 21 List of Large Scale Models with a brief description about each model. Table 2.2: ............................................................................................... 28 List of years, storms, and storm specific dates used in this research. Table 2.3: ............................................................................................... 31 List of large scale models used for producing track forecasts and large scale models used for producing intensity (maximum wind) forecasts. vi LIST OF FIGURES Figure 1.1: ............................................................................................. 5 Track mean absolute errors, in kilometers, for 1996 to 2006 for the OFCL (solid, dark), GFDI (long dash, medium), and FSSE (short dash, light). The red group is the 12 hour errors; the green group is the 36 hour errors; and the blue group is the 72 hour errors. The FSSE information was only available starting in 2004. Courtesy of the National Hurricane Center. Figure 1.2: ............................................................................................. 6 Maximum wind speed mean absolute errors, in ms-1, for 1996 to 2006 for the OFCL (solid, dark), GFDI (long dash, medium), and FSSE (short dash, light). The red group is the 12 hour errors; the green group is the 36 hour errors; and the blue group is the 72 hour errors. The FSSE information was only available starting in 2004. Courtesy of the National Hurricane Center. Figure 2.1: ............................................................................................. 9 The magnitude of track errors, in kilometers, for the 1999 Atlantic Hurricane season, for the Florida State Superensemble, as compared to the ensemble mean and the respective member models. For each time period on the right the columns correspond to the legend top to bottom. From Williford et al. (2003). Figure 2.2: ............................................................................................. 12 A schematic of a Florida State Superensemble forecast in time, with the regression coefficients calculated in the training phase being applied to the generation of an FSSE forecast in the forecast phase. From Krishnamurti et al (2001). Figure 2.3: ............................................................................................. 15 Model domain coverage of WRFA for Hurricane Ivan on September 12, 2004 at 0000 UTC 00 hr showing sea level pressure. vii Figure 2.4: ............................................................................................. 17 Model domain coverage of MM5 for Hurricane Ivan on September 12, 2004 at 0000 UTC 00 hr showing sea level pressure. Figure 2.5: ............................................................................................. 19 Model domain coverage of HWRF for Hurricane Ivan on September 12, 2004 at 0000 UTC 00 hr showing sea level pressure. Figure 2.6: ............................................................................................. 24 Model domain coverage of GFDL, showing the three nests with the outermost nest (mesh C) having .166 degree resolution and the innermost nest (mesh F) having a .083 degree resolution within a five by five degree domain