As of this Wednesday, it is expected that Atlantic Storm in formation south of the Azores is moving towards Canary Islands. Simultaneously, the entry of warmer and more humid air of subtropical origin will contribute to the intense and locally persistent rainfall.
On Wednesday, squalls are expected in the western islands, although Thursday will be the most adverse day, when the most intense and persistent precipitations affect the entire archipelago. That day the intensities may exceed 15-20 mm in one hour and the accumulations 40-60 mm in twelve hours in Tenerife, Gran Canaria and the eastern islands. As of Friday, the storm will tend to be losing entity while moving to the east. Rainfall, although expected to be less intense, will persist over the archipelago and may be locally strong. It is very likely that they also affect the southwest of the peninsula.
Facing the Weekend an important and abrupt change of weather is expected in the Peninsula and the Balearic Islands, although more adversely in the north of the peninsula. It is expected the entrance of an arctic air mass that will replace the warm mass that we have these days and that will cause a generalized and sharp drop in temperatures, as well as significant snowfalls in the surroundings of the mountain systems of the north of the Peninsula.
The Saturday a very active front will cross the Peninsula from northwest to southeast leaving in its wake rains and generalized showers, more intense and frequent in the northern half and central peninsular area and unlikely in the extreme southeast. After the passage of the front there will be an outbreak of cold air in the Peninsula with a sharp and generalized decrease in temperatures, notable in large areas of the interior of the peninsula. As a result, the level of snow can drop to 1000 meters, leading to the first major snowfall in the north of the peninsula.
It is likely that the winter situation will continue, at least, during the first days of next week.