The dry, stable and anticyclonic weather of a good part of this month of October will change in this bridge of Todos los Santos because an ‘atmospheric river’ driven by open winds will generalize the autumnal atmosphere to the irrigate most of the peninsula and the Balearic Islands with rain, especially between Friday and Sunday.
In addition, the greater cloudiness will reduce the thermal amplitude, with which there will be less temperature difference between day and night.
All this is due to the influence of a deep storm located in the North Atlantic and with very active fronts now blocked by the anticyclone of the Azores, but that will come with the withdrawal of high pressures.
“We are on the threshold of an important time change in our country. The withdrawal of the anticyclone will allow the arrival to the peninsula of very moisture-laden winds after traveling long distances over the Atlantic, giving rise to several rainy days in a large part of the peninsula, especially in its western half, “the spokesman for the State Meteorological Agency (Aemet), Rubén del Campo, in statements collected by Servimedia.
These flows are called open winds, that is, humid, temperate and coming from the southwest that constitute ‘atmospheric rivers’ and, according to Del Campo, “carry large amounts of water vapor from tropical and subtropical areas to mid-latitudes, where they translate into abundant rains ”.
As those winds are temperate, there will not be a very cool atmosphere in general during the bridge. “Even the temperatures will be high for the time in the Mediterranean “said Del Campo.
Stable weather will continue in the next few hours in much of Spain, with morning fog banks and somewhat cloudier skies on the Mediterranean coast and the Balearic Islands, where possible stormy and scattered showers are expected, more likely on Wednesday on the coast of Almería and Melilla, and on Thursday in the Balearic Islands and coastal areas of Catalonia and Valencian Community.
The sun will continue to shine this Thursday in large areas of the country, while, according to Del Campo, “the frontal system will get closer, which, to put it in some way, will open the spigot for the change of weather in the coming days and the arrival of the ‘atmospheric river’ “.
Thus, starting at noon this Thursday, it will rain in Galicia and nearby areas of Asturias and León, and rainfall will be locally strong and persistent in the west of the Galician region.
The temperatures will hardly change Wednesday and Thursday, which will continue the marked difference between the night and the day of the last days. In fact, it will freeze slightly in the moorlands of the central peninsula and mountainous areas of the north, while the thermometers will show 26 or 27 degrees in the afternoon in the Guadalquivir valley.
That first frontal system will advance on Friday from west to east of the peninsula leaving rainfall in its wake, although they will not reach the Valencian Community, Murcia and Andalusia Oriental. Nor is it expected to rain in the Balearic Islands.
Instead, rainfall will be locally strong and persistent in Galicia, the west of Castilla y León, Extremadura and the extreme west of Andalusia. In some cases, more than 15 liters per square meter can accumulate in one hour or more than 40 liters per square meter in 12 hours.
On Saturday it will rain again in much of Spain with the arrival of the ‘atmospheric river’ driven by moisture-laden open winds, which transport a large amount of water vapor after having traveled long distances over the Atlantic, according to Del Campo.
In fact, the rains will reach the Mediterranean peninsular regions and the Balearic Islands, although more weakly than in the rest of the peninsula.
The center and the southern half of the peninsula will become the areas with the most abundant rains, which in some places will be accompanied by a storm. “In some parts of southern Castilla-La Mancha and western Andalusia they could be registered throughout the day more than 50 or 60 liters per square meter “, Del Campo pointed out.
As for Sunday, it will be a day “fully autumnal in most of the peninsula”, according to Del Campo. It will rain abundantly in the western half and less in the Balearic Islands and areas of the southeast of the peninsula. Thus, most of Spain will chain three rainy days.
In addition, the humid and temperate winds from the southwest will blow with strong gusts between Friday and Sunday in coastal and mountain areas.
Regarding temperatures, the increase in cloud cover will cause Friday morning is warmer than previous days, while it will be a bit colder during the day, especially in the western half of the peninsula. On the other hand, it will be slightly warmer in the Mediterranean area.
On Saturday this situation will be reversed, that is, temperatures will drop on the Mediterranean façade and will rise in the rest of the peninsula. And on Sunday there will be a general thermal rise.
“The environment will not be too cool during these rainy days. In fact, the night frosts will disappear, it will practically not drop below five degrees at any point on the peninsula. And on Sunday the maximum temperatures could even exceed 25 or 27 degrees in the regions bathed by the Mediterranean, “added Del Campo.
The uncertainty in the forecast increases as of Monday. However, it is likely that that day there are clouds and rains in much of the peninsula, but weaker and intermittent than in previous days and with greater affectation in the center and the southern half of the peninsula.
As of Tuesday, it seems that the rains will be concentrated in the extreme north of the peninsula, the skies will be clearer in the rest and temperatures will drop in the north, with possible frosts in large areas of the interior of the peninsula.
Finally, The Canary Islands are left out of this change of time. The trade winds will ease in the coming days and cloudy intervals are expected in the north of the islands and possible evolution clouds in the rest of the archipelago, with the occasional scattered shower. The trade winds are likely to intensify early next week.