Previous studies have analyzed various atmospheric tornado parameters in a Tropical Cyclone (TC) environment. This study focuses on the evolution of these parameters through a TC
landfall. The TCTOR dataset, which assigns all TC tornadoes to their respective TC, is used to group qualifying events from a pool of 1201 tornadoes during the period of 1995-2010 into eight
time intervals relative to TC landfall. The environment is then analyzed using seven operationally used tornado parameters. A statistical, spatial, and sounding analysis is performed to
determine how the tornadic environment evolves over time after landfall. Analysis shows that statistically significant differences in the mean value of each parameter are found between
pre-landfall, post-landfall, and various time interval comparisons. Composite field charts and case studies show that the wind shear parameters at different vertical layers help explain
tornado concentrations in space at different time intervals. In addition, a comparison of composite field charts is made between the larger pool of 32 TCs in the ALL composite and the 10 TCs
representing the lowest tercile, with respect to the total number of tornadoes produced. This comparison shows higher magnitudes of shear parameters in the ALL composite. Combined with model
derived soundings of three prolific tornado producing TCs, this study shows that the increase in shear in the lowest layer (0-1 km) is the best diagnostic tool to explain the increase in
tornado occurrences at TC landfall. This finding supports prior research, which showed that low level shear maxima coincided with tornado locations. The increase in shear in the 0-3 km and
0-6 km layers at later time intervals is found to be the best diagnostic tool to explain the secondary increase in tornado occurrences after 24 hours past TC landfall. Additionally, 24 hours
after TC landfall appears to be the critical time that separates weaker TC tornadoes at prior time intervals from stronger ones that resemble mid-latitude cyclone tornadoes that occur after,
based on parameter values, hodograph analysis, and conceptual models. Lastly, the Significant Tornado Parameter (STP), used with discretion, is shown to work well in diagnosing tornado
occurrence in some time intervals but proves to be a poor tool in others. / A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of
Science. / Fall Semester, 2014. / November 3, 2014. / hurricanes, NARR, parameters, STP, tornadoes, wind shear / Includes bibliographical references. / Peter Ray, Professor Directing Thesis; Robert Hart, Committee Member; Mark Bourassa, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_252893 |
| Contributors | Speransky, Stanislav (authoraut), Ray, Peter S. (professor directing thesis), Hart, Robert Edward, 1972- (committee member), Bourassa, Mark A. (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting department) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (87 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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