Examining tropical cyclone development in the Southwest Caribbean Sea

• Main Authors: Zavadoff, Breanna, Galarneau, Thomas J., Lawler, Michael, Varuolo, Arianna
• Format: Text
• Language: unknown
• Published: University Corporation For Atmospheric Research (UCAR) 2015
• Subjects: Pacific; North Atlantic
• Online Access: https://dx.doi.org/10.5065/ame3-0h17; https://opensky.ucar.edu/islandora/object/manuscripts:925

Tropical cyclones (TCs) that develop in the southwest Caribbean Sea (SWCS) commonly make landfall due to their relatively close proximity to land masses, bringing flooding rains, high winds, and destructive storm surge to the impacted areas. Despite the dangers posed by SWCS TCs, there are relatively few studies in the refereed literature that examine the TC genesis climatology and preTC development synopticscale flow environment in this region. The aim of this study was to use the National Hurricane Center best track database and gridded atmospheric reanalysis data to construct a climatology of TC formation, determine the origin of the lowlevel precursor disturbance, and diagnose the synopticscale flow pattern in which TC genesis occurs in the SWCS from 1990-2014. Results are presented from the synoptic climatology, composite, and case study perspectives. The results show that TC formation in the SWCS occurs preferentially in October and November, later in the season compared to the North Atlantic Basin as a whole. Of the 45 TCs identified, 28 occurred in a baroclinic environment on the southeast flank of an uppertropospheric trough. The upperlevel trough results most frequently from downstream energy propagation via a Rossby wave train initiated in the western North Pacific. Preliminary findings suggest that the upperlevel trough and attendant baroclinicity provide a focus for enhanced synopticscale ascent, which aids in moistening, destabilization, and maintenance of convection. Results from this study may provide aid in mediumrange forecasting of SWCS TCs through awareness of synoptic precursors and their effects.