The storm is also expected to raise water levels in rivers and streams, especially south of the Tagus River, increasing the risk of flooding in several regions.

Mainland Portugal is expected to face worsening weather conditions from Saturday morning as Storm Marta moves in, bringing heavy rain, snowfall, strong winds, and rough seas. The storm is also likely to cause rivers and streams south of the Tagus River to rise again, increasing the risk of flooding.

According to Portugal’s Institute for the Sea and Atmosphere (IPMA), the worst conditions will begin in the southern region, particularly along the coast. Persistent and sometimes intense rainfall is forecast, along with wind gusts reaching around 100 km/h, and up to 120 km/h in mountainous areas.

Forecasters expect the heaviest rainfall to fall south of the Tagus River, including the greater Lisbon area, with the highest totals likely in Alentejo and the Algarve mountains. Rainfall could reach around 60 mm within 24 hours, which is expected to cause rivers and streams in these regions to rise again, increasing the risk of flooding, according to Portugal’s Institute for the Sea and Atmosphere (IPMA).

From Saturday afternoon onwards, as the storm system moves east, winds are forecast to strengthen along the central coast, with gusts up to 90 km/h and periods of heavy rain.

Snowfall is expected above 900 metres, with the snow line temporarily rising to between 1,200 and 1,400 metres during the day. In the Serra da Estrela mountains, snow accumulation could exceed 25 cm above 1,400 metres.

The IPMA also warned that sea conditions are going to remain very rough, with west-facing waves reaching up to seven metres along the west coast, particularly south of Cape Carvoeiro. Maximum wave heights could reach 13 metres. Along the Algarve’s south coast, southwest waves of up to five metres are expected.

The entire mainland Portuguese coast remains under an orange weather warning for dangerous sea conditions at least until Saturday.

Meanwhile, the districts of Évora, Setúbal, Santarém, Beja, and Portalegre are under a yellow warning for heavy rain until late Saturday morning. Braga, Castelo Branco, Viana do Castelo, Vila Real, and Guarda will be under an orange warning for snow throughout the weekend, while Faro, Setúbal, and Beja face an orange warning for strong winds on Saturday.