Snow in March in Mallorca is not unknown. | J. Taberner

There will be a dramatic change in the weather this week. Sunny and settled conditions across Spain will be replaced by temperatures at "midwinter values" and with snow at low levels.

The met agency Aemet says that the change will begin on Wednesday, with temperatures dropping significantly on Thursday. Until then, and while temperatures will be normal for the time of the year, strong winds are expected to provoke rough sea conditions, with waves of up to four metres in the Balearics. There is a yellow alert for the coasts on Tuesday.

A very cold air mass will move in from the continent on Thursday. This will spark off storms, the location of which will be difficult to forecast because of movement in a southwesterly direction rather than coming from the Atlantic to the east, which is the usual route for storms.

The fall in temperatures will be particularly evident in the southeast of the mainland, in the Mediterranean area and in the Balearics. On Friday and Saturday, temperatures will be between five and ten degrees lower than is the normal for the time of year. Saturday is the first day of astronomical spring, but Aemet suggests that it will feel like the middle of winter.

The weather will begin to improve on Sunday. Meanwhile, snow in Mallorca is very probable, with falls forecast to be down to 800 metres.