Sensitivity Analysis To Different Parameterization Schemes On A Subtropical Cyclone Over The Eastern North Atlantic.

Depending on the thermal structure and dynamics, there are different types of cyclone in the troposphere. Subtropical cyclones (STC) are low pressure systems that share tropical and extratropical characteristics, having hybrid thermal structures. In October 2014, a STC landfall the Canary Islands, causing widespread damages due to the strong winds and precipitation over the area. The system began to develop in October 18 and its effects lasted until October 21. The cyclone evolved from a typical extratropical cyclone, detached from a highly meridional atmospheric circulation and which became a stationary cut-off low in the subsequent days. Moreover, the cloudiness pattern consistent with the cyclone evolution described in the Cyclone Phase Space (CPS) diagrams, is highlighted. During the extratropical phase a frontal cloudiness pattern is observed. This type of clouds (cumulus and stratiform) could have become potential candidates for intense icing. Furthermore, during its intensification phase, deep convective processes are carried out due to the sensible and latent heat released from the ocean. In the same way, noticeable icing processes could have been expected. The good simulation of this type of cyclones continues being a significant challenge due to its rapid intensification and its particular characteristics. Therefore, a probabilistic forecast must be taken into account in order to obtain more complete information about these extreme events. Moreover, it is convenient to know the physical options and parameterizations schemes that best simulate this type of cyclones in order to be able in a near future to carry out more accurate predictions. In this study, several numerical simulations are performed using the WRF model so as to carry out a sensitivity analysis of its different parameterization schemes during the development and intensification of the STC. Accordingly, the combination of parameterization schemes that had better simulate this type of phenomena will be exposed. In particular, the combinations of parameterization that include the cumulus schemes had the most positive effects on the model results.