A dramatic refresher all around: Autumn officially arrives today with a bang.

BarcelonaBe careful when leaving home today, as it has cooled down considerably. In many cases, the drop compared to yesterday morning is between 4 and 9°C. Early in the morning, temperatures ranged between 13 and 17°C across much of the coast and pre-coast, between 8 and 13°C inland, and markedly cold in the high Pyrenees, where temperatures dropped below 0°C in areas such as the 2,500 m coast of Boí, in the Alt. This significant cooling is the result of the arrival of a northerly wind of polar origin today, the day we officially enter autumn at 8:19 p.m. Therefore, the new season will enter with a bang, with a suddenly autumnal atmosphere after the summer heat of recent days.

All this follows the wave of heavy storms and downpours that swept across the country yesterday, causing numerous incidents, leaving over 100 l/m² in some cases and significant flooding of rivers and streams (you'll find all the details and images of the episode at the end of this report). Today will be calm and sunny in many regions, with northerly winds at extremes. However, in the afternoon, there will be some irregular showers in the Pyrenees and the northeast, with heavy rainfall above 2,000 m. Midday will also be markedly cooler, and temperatures will bottom out on Tuesday, with values below average and a more October atmosphere.

Monday: Soda is everywhere

Today, the front is already history, but the very cold air it has brought back will generate cloudiness in areas of the north of the country. However, sunny and calm weather will prevail throughout the day in most regions, and it will not rain anywhere in the morning, with traces of clouds in the regions of Girona, northern Barcelona, and the Pyrenees. From midday, dark clouds will gather in the northeast and the Pyrenees, leaving some spotty, light to moderate showers in parts of the northeast and the Pyrenees. The snow level will hover around 2,200 m and we could see the first dustings of the season at higher altitudes, especially in the Alt Pirineu. In fact, the atmosphere will be full of autumn throughout the day in the Pyrenees, with cold temperatures at high altitudes. Meteocat has issued a warning for heavy rain in some northeastern regions for this afternoon, and warnings that will extend to more regions tomorrow:

The week begins with a much cooler atmosphere, as temperatures have plummeted, making it necessary to bundle up early in the morning. And in the middle of the day, highs will hover between 19 and 24°C, clearly lower in mountainous areas and inland northern areas. We will therefore be talking about a fully autumnal atmosphere on the day we enter astronomical autumn, specifically tonight at 8:19 PM.

Fresh strength throughout the week

We're looking forward to some much cooler days, more typical of October than mid- to late-September. Starting Tuesday, the highest highs will barely exceed 22 or 23°C, and around 16°C in the Pyrenean valleys. It will be cold at night in many inland regions and mountain areas, where the temperature will drop below 0°C at high altitudes for the first time in many months. In the Pyrenean valleys, lows will be around 4°C, hovering around 10°C inland and in the West, and around 16°C on the coast. On Tuesday, temperatures will bottom out, and instability will increase, with irregular showers and storms reappearing in the regions of Girona, Barcelona, ​​the Pyrenees, and the Pre-Pyrenees. The snow level will hover between 1,800 and 2,000 m, leaving new snowfalls in the Pyrenees mountain range.

Assessment of the episode of downpours and strong storms

The passage of a front and a pocket of cold air caused downpours and severe storms across the country yesterday, Sunday. Some of the areas most affected by the storm were central Catalonia, the Barcelona coast and pre-coast, Terres de l'Ebre, and the northeast. In some cases, the showers lasted for a long time, leaving significant amounts of precipitation. For example, in areas of Bages, the northern Vallès Occidental, and Solsonès, more than 100 l/m² accumulated. Yesterday's downpours in Montserrat briefly reminded us of the severe flooding at the monastery on June 10, 2000. That night, 100 l/m fell.² In just 45 minutes, the effects were much worse because the storm was very static and hit the mountain range even more violently than yesterday. The Ebro River also received heavy rain, with intense hail that caused damage in towns such as Riumar, Deltebre (Baix Ebre), and Sant Jaume d'Enveja (Montsià). The rain caused quite a few incidents in general, including landslides, flooding, road closures, and sudden and significant flooding of rivers and streams. These are the most notable rainfall records and images from Sunday:

• 130 l/m²: Montserrat - Sant Dimes
• 117 l/m²: Fillers
• 115 l/m²: El Port del Comte
• 88 l/m²: Gisclareny
• 88 l/m²: Sabadell - Parc Agrari
• 73 l/m²: Cadí Norte
• 69 l/m²: Alinyà
• 62 l/m²: La Pobla de Segur
• 57 l/m²: Gutters
• 55 l/m²: Tempering
• 55 l/m²: Núria
• 55 l/m²: Castellbisbal
• 54 l/m²: Font-rubí
• 53 l/m²: Lladurs
• 51 l/m²: Ódena
• 50 l/m²: Oliana
• 50 l/m²: Luck
• 48 l/m²: Vacarizas
• 42 l/m²: Terrace
• 41 l/m²: Ulldeter
• 40 l/m²: El Prat de Llobregat
• 36 l/m²: Amposta