The Analysis of Regional Atmospheric Structure in Time of Heavy Snow-Fall in Kerman Province

As the study area is situated in warm and dry climate, the very strong anomalies should occur in the atmosphere to form snow spreading widely, one of the condition is atmospheric cut-off. In order to study snowfall in Kerman province, the data were used from 10 meteorological stations within the province. To explain they structure and movement of the precipitation system, the data from web- site of National Climate and Environmental Prediction and the Atmospheric Research (NECP/NCAR) from the upper atmosphere stations were used and synoptic maps were drown at the time of occurrence of the phenomenon. The results showed that on the day before rainfall, there was the poor instability in the region, but the next day's instability in atmosphere the becoms intense in different layers. Synoptic maps are indicated a very deep landing in central of Iran in the core of cut-off with an average temperature of -25 degrees. Cold air fall in the upper troposphere and its contact with lower latitude air, caused a deep frontal in the region. Other major reasons include a placement area beneath the jet stream core divergence and strong eddy in central Iran. With the establishment of the anticyclone over Pakistan, and by entering the system in the region, and subsequently by passing through the Oman Sea and the acquisition of sufficient humidity which is providing the heavy snow in the region.