According to IPMA, until Tuesday the weather in mainland Portugal will be conditioned by a depression centred southwest of the Iberian Peninsula.
Due to the depression, dust is expected to arrive over the continent from North Africa, which should have low concentration, but may increase temporarily between the end of the day on Saturday and then on Sunday.
An increase in cloudiness is also forecast from today, with the possibility of showers in the Algarve later in the day.
On Saturday, the showers will be in the south, and may extend to the central region from the afternoon. On Sunday, showers will be weak and infrequent, increasing the frequency again on Monday and Tuesday, and may also occur on these days in the north.
"This weather situation has some uncertainty associated mainly due to the position of that depression. It should be noted that the rainy regime presupposes intermittent and scattered precipitation, both spatially and temporally," said IPMA in a statement.
As for temperatures, IPMA indicates that it will undergo slight variations, with the minimum values between 08 and 13 degrees Celsius on the coast and between 06 and 09 degrees in the interior, being slightly lower, between 03 and 6 degrees Celsius in the interior north and Beira Alta.
The maximum temperature will be higher than normal for this time of year, between 17 and 24 degrees in most of the mainland.
The wind will be weak to moderate, blowing moderate to strong in the Algarve on Saturday and in the highlands, especially in the Centre and South.
The IPMA also predicts sea disturbances, with waves on the southern coast of the Algarve being 1 to 2 meters and being between 2 to 2.5 meters today and Saturday.
For the archipelago of Madeira periods of cloud and occurrence of showers are to be expected, especially on the northern slopes and highlands.
On Monday and Tuesday, the probability for precipitation to occur decreases and showers, if they occur, will be generally weak.
It is also expected moderate to strong wind and maximum temperatures between 16 and 22.
In the Azores, between today and Monday cloud coverage is to be expected but alternating on all islands and significant precipitation is not be expected.
On Tuesday, the "approach and passage of a cold frontal surface with swells, with slow movement and moderate activity" will affect the weather on all islands, starting with the islands of the Western Group and extending gradually over the rest of the Archipelago.
Therefore, it is expected an increase of cloudiness with periods of light rain passing to light showers and, only on the islands Fores and Corvo, a slight increase in wind intensity.
Maximum temperatures will vary between 15ºC to 17ºC.