Abstract
One of the main objectives of this original research is to establish and develop the annual and seasonal maps of the Isokeraunic level (Thunders days, Td) for the country. Also, collect and document thunderstorms and lightning activities in Saudi Arabia and present the steps of development and validation of these authentic maps.
A new annual thunder day maps for Saudi Arabia are presented, on the basis of these maps, the distribution of thunderstorms over the country is analyzed in terms of the development factors required for determining lightning performances of transmission lines. Thunderstorm days (Td) in different areas of Saudi Arabia specifically those where lightning strikes are more likely to occur has been determined. The results of what has been established in this paper are based on data and records available on lightning incidence in Saudi Arabia by the Presidency of Metrology and Environment (PME).
These maps will indicate the thunderstorm activities location, and frequency where lightning strikes, such information is very valuable for the design engineers of the transmission and distribution lines and operation for optimum selection, and insulation coordination of the lightning protection systems.
Thunderstorms are most frequent over the southwest of the country, and generally decrease as going to the west direction. Thunderstorm frequency does not, in general, appear to vary in any consistent way with rainfall. There appears to be no evidence of any widespread temporal trend in thunderstorm frequency