THE INVESTIGATION of WATERSPOUT STRUCTURE in a CASE STUDY OVER SOUTHERN COASTS of IRAN (BUSHEHR PROVINCE, DECEMBER, 15, 2017)

Tornados are rotating columns of cloud that can be in touch with the ground. These rotating clouds are formed under the cumulonimbus clouds and often can be seen as funnel clouds. If these tornadoes are formed on the surface of the water, they are called waterspout. The structure of this atmospheric hazard is very similar to the thunderstorms. The threeconditions include static instability, lower surface humidity and lifting mechanisms near the earth surface are necessary for the creation of convection Figure 1) There are few studies in Iran about the waterspout events, therefore the aim of this study is to investigate waterspout as a mesoscale phenomenon and analyzing the synoptic patterns at the time of theoccurrence of this phenomenon. In order to study the most important indices related to the occurrence of this phenomenon in this section, we study the sea level pressure, wind, humidity vertical profile and LI, Helicity, CAPE and CIN indices.