An exceptionally powerful thunderstorm blew down trees and power lines in many parts of the the Helsinki region at about 7:00 PM Tuesday evening. Cellars in many places were flooded by the torrential rain.
Lightning strikes and trees falling on power lines cut off electricity supplies to many consumers in Espoo and Kirkkonummi. Jarmo Ström of the electric utility E.ON Finland estimated that at least 2,500 households were affected by blackouts in different areas.
In Helsinki the thunderstorm blew trees onto roads, and flooding drains caused traffic delays. On one street in the centre of the city the water was about one metre deep.
Two people were injured in the parking area of Helsinki’s Aurora Hospital earlier in the afternoon when a tree blown down by a gust of wind fell on them. Two cars in the car park were damaged by the falling tree.
The railway line between Helsinki and Turku was cut off, and passengers were taken by bus past the obstructions.
The cold front carrying the thunderstorms moved to the west and north on Tuesday evening and Wednesday morning. Reports of trees falling on houses came from the southwest.
The thundershowers brought large amounts of rain in a short period of time. In Helsinki, rainfall of up to 20 millimetres was recorded during the heaviest downpours.
Meteorologist Juhana Hyrkkänen of the Finnish Meteorological Institute notes that the Tuesday evening thunderstorm was not exceptional: similar storms occur about once every summer.
Maritime traffic was fairly normal. The smallest high-speed passenger hydrofoils operating between Helsinki and Tallinn remained in port all day.
