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A severe thunderstorm was initiated over the Balkan mountain range (Stara planina in Bulgarian) in north-western Bulgaria. It moved to the east-northeast and developed quickly to a supercell badly affecting the town of Byala Slatina and Pleven, one of the biggest cities in northern Bulgaria in the afternoon hours on 15 May 2018. The storm caused all possible types of convective hazards: strong winds, large hail, heavy rain and accompanying flash flooding. It inflicted a lot of damage on properties, cars and infrastructure. Strong winds uprooted trees and caused power outages. In the municipalities of Byala Slatina and Pleven has been declared a state of emergency.
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