Analysis of Extratropical Transition or Dissipation of TCS that made Landfall in the Contiguous United States from 2000-2019

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Rodríguez, Manuel Iván Ramos
TCs that made landfall over the contiguous US for the past 20 years were studied to further examine the difference in synoptic patterns between land falling TCs that underwent extratropical transition (transitioning storms) and those that didn't (became subtropical or dissipate out as lows; dissipating storms). Using the HURDAT database, TCs with similar tracks and similar landfall areas in the US were selected, areas that experienced both land falling TCs that became extratropical and TCs that didn't were highlighted. Focus was brought to two main groups of land falling TCs, those that made landfall in the Gulf of Mexico Coast and those that made landfall on or near Florida. These two main groups were further divided into dissipating storms and transitioning storms. Upper and surface level maps, along with PV maps, phase space diagrams and satellite imagery were used to analyze these four groups of land falling TCs. Both composite analyses and individual case studies were done. Preliminary results indicate that most of the TCs that underwent ET interacted with a significant low level baroclinic boundary while inland but with some of them being officially classified as extratropical sometime later than when it had all of the characteristics of one. Most case studies only had slight differences with their respective composites with TC Ivan having the higher discrepancy when it made landfall in the west gulf area. Future work includes increasing the time frame of the analysis and coalescing the different synoptic conditions present for TCs that underwent ET to simulate upper and surface level synoptic environments that would be beneficial for this transition to take place and would help forecasters to better predict them.