The gusts of strong winds that hit Estonian shores in the early hours topped at 31.4 meters per second, met office reports. Ferry services between the mainland and islands have been largely suspended and Baltic Queen, which runs between Estonian and Finland, hit a dock in Helsinki.
The islands are the hardest hit, with 3,600 household without power supply.
The wind has died down a little over the day but will pick up again on Tuesday, with gusts up to 23 meters per second. The storm is expected to last until Wednesday but another cyclone could on Friday.
The seawater level has so far topped at 130 centimeters in Pärnu. There is no risk of floods in coastal towns, the met office said, but the levels can be followed here.
The ferries connecting the islands of Hiiumaa, Vormsi and Kihnu to the mainland, and Hiiumaa with Estonia's largest island Saaremaa, are not running regularly or not at all. Passengers are advised to check the departure information before making the trip.
The storm has been dubbed Gorm in Sweden, where the gusts reached 38.4 meters per second, leaving around 50,000 households without electricity.
Editor: M. Oll