Comparison of GPS Dropsondes between developing and non-developing disturbances in the Atlantic

A comparative study of GPS dropsonde data of the environment surrounding developing versus non developing tropical disturbances in the Atlantic is presented. Because of the lack of research in this area, there was a desire to go into the dropsonde archives to see how much data could be acquired for pre-depression stages of the disturbances on the period from 2004 -2008. The selected developing cases were Pre-Gert from 2005 and Pre-Fay from 2008. The selected non-developing cases were Wave #4 and Wave #6 from the NAMMA field experiment in August- September 2006. The intention was to compare and contrast the environmental conditions that surround the disturbances in terms of moisture, temperature and wind shear, to see if the low vertical wind shear, the relatively cold temperatures and the high amounts of relatively moist air were determining factors for the development as the concerning literature suggested. After compositing the selected soundings, no significant and general difference between the cases was found. However, the results somewhat supported the favorable characteristics for development, but those features were not exclusive of the developing cases. The data must be discriminated in terms of the location in the Atlantic and other variables, such as vorticity, SAL influence, sea surface temperature and the characteristics of the convection itself, need to be taken into account before reaching formal conclusions. This study serves as a starting point for further research that may make a positive impact or have a significant role in improving the forecasting of the development of cyclones.