Southern and eastern Finland face heavy rain and strong winds this weekend as a low-pressure system moves towards the country, according to forecasts from Foreca and the Finnish Meteorological Institute.

Foreca said on Friday that its forecast for the system had strengthened. The weather service now expects widespread heavy rainfall, with 40–50 millimetres forecast across parts of southern and eastern Finland during the weekend.

The Helsinki region lies within the area expected to receive heavy rain.

Most of the rain is forecast to fall between Saturday night and Sunday morning. A daily rainfall total above 20 millimetres meets Finland’s threshold for heavy rain.

The low-pressure system will develop as a weather front moves from northern Italy across Central Europe towards the Baltic region. Foreca expects the centre of the low to form near Poland before deepening as it travels north.

Rain will start spreading into southern Finland during Saturday evening before reaching wider areas of southern and central Finland overnight and on Sunday.

Foreca forecasts 40–50 millimetres of rain across a broad area in southern and eastern Finland over the weekend. That represents more than half of the average rainfall for the whole of August in some locations.

Wind speeds are forecast to increase during the night between Saturday and Sunday. Foreca said gusts in southern and eastern Finland could reach levels associated with wind damage. The strongest winds in southern Finland are expected overnight, with strong gusts continuing across central and eastern areas on Sunday and into Monday.

Winds will come from the north and north-east. Foreca said this direction increases the risk of damage because winds in Finland more often arrive from the west or south-west.

Thunderstorms are not expected to form on a broad scale, though isolated lightning is possible along the southern coast overnight.

Temperatures are expected to remain between 15 and 20 degrees Celsius in most areas during the weekend, according to the Finnish Meteorological Institute. Temperatures will fall under persistent rain and drop to around 10 degrees at night.

HT