Synoptic Analysis of Mashhad Severe Thunderstorms

Thunderstorms are one of the most destructive weather phenomena, and knowing the mechanism, development, and development of such storms can be of particular help in counteracting and mitigating the damage.

In the present study, thunderstorms with rainfall of more than 10 mm of Mashhad synoptic station in a 61-year statistical period (2010-1901) have been investigated. Thus, first the codes related to the occurrence of the thunderstorm phenomenon and then the precipitation of more than 10 mm related to the mentioned phenomenon were extracted and then the daily data of the average sea level pressure from the series of retrieved data series. NCEP / NCAR were harvested within 12 days. Finally, with the method of basic component analysis (PCA) and cluster analysis, sea level rotation patterns that played a role in the formation of thunderstorms were classified.

The study showed that thunderstorms of the Mashhad region, has been created by two general patterns. The first pattern, in the SLP, formed the cell of the monsoon system over the country advocated hot and humid air needed for thunderstorm by motion of cyclonic and at the upper levels (850 and 500 hpa) the trough of westerly winds is located over the studied area that led to the thunderstorms occurrence. In The second pattern, the Sudan system expanded from southwest toward northeast and then passed over the Persian Gulf and the Sea of Oman, that led the humid advection into the study area and at the upper levels (850 and 500 hpa) trough of westerly winds is located over the studied area that provided dynamic rise and consequently led to thunderstorms. In both precipitation pattern, main source of moisture was the South Seas and the major factor of uplifting was the western trough.