Severe weather that has been tormenting Poland and the Baltic countries will reach Finland on Saturday, beginning in the afternoon in the southwest. The Finnish Meteorological Institute (FMI) says the thunderstorms will be the worst Finland has experienced so far this summer.
FMI weather experts say the front is still developing over the Swedish island of Gotland, but winds that it created reached speeds of 40 meters per second over Poland, where some of the storm's precipitation fell as hail.
After a cool summer, temperatures in the Baltic Sea have stayed quite tepid, and the FMI's meteorologist Jari Tuovinen says this will temper the tempest considerably before it reaches the Finnish coast. He now predicts the storm front will bring heavy rain and thunder to all parts of southern Finland below the Turku-Lahti-Joensuu line.
"Individual thunder clouds will move quickly, but there will be a long line of them, so it may seem as if the storm goes on and on," Tuovinen says.
The FMI has issued several thunderstorm warnings for the Archipelago Sea and the Gulf of Finland and advises all boaters to stay ashore. Winds over land may also reach dangerous velocities of more than 25 meters per second as the front moves east.
Torrential rain in places
Some areas may receive dozens of millimetres of rainfall, up to a half centimetre per hour. This may cause some storm water systems to overflow.
Two major events taking place in Helsinki on Saturday night, the Helsinki City Marathon and the Flow Festival, are aware of the potentially dangerous situation and have taken the necessary precautions.