The storm which first hit along the west coast on Wednesday evening was moving towards the southeast on Thursday morning as winds intensified in the southwest and western inland areas.
More than 65,000 households were reported to be without electrical power on Thursday morning. The largest number of power outages have been seen in Ostrobothnia.
One operator, the electrical power company Vaasan Sähköverkko, estimated on Thursday that it will take several days to fully restore power, and that repairs in the electricity network will take weeks.
In addition to sustained high winds, gusts briefly topping 30 metres per second were recorded at several spots along the Gulf of Bothnia with one measured at 35.3 m/s by a weather station in western Finland town of Jakobstad (Pietarsaari in Finnish).
Readings of 27.1 m/s have been recorded in the Turku area, and 26.8 m/s at Vaasa Airport.
Yle meteorologist Nina Karusto says that high winds are now forecast for the southern Uusimaa region and more easterly parts of the country as the storm centre moves towards the southeast.
The storm has also brought heavy rainfall to a zone north of a line running between Vaasa and Joensuu. Rains have been heaviest in Kajaani, where accumulated precipitation has reached up to 60 millimetres. Average rainfall for the whole of September in the area is 50 millimeters.
Areas further south are expected to receive considerably less rain, and Finnish Lapland is likely to be spared the storm altogether.