A change in the weather is coming that will open its doors in autumn.

BarcelonaThe most active part of the disturbance is generating very powerful storm clouds. Storms have accumulated up to 125 l/m² in Montserrat (Sant Dimes) and 111 l/m² in Rellinars (information until 6:30 p.m.). Extreme caution is required, especially regarding mobility, and avoid traveling unless absolutely necessary. Do not cross flooded passages or streams.

The bout of heat and muggy conditions we've experienced in recent days, which felt more like late August than late September, has given way to a radical change in the weather. The approach of a front and a cold air jam has reactivated the instability, with showers and storms affecting every part of the country. This has led Meteocat to issue a warning for heavy rain in all regions (yellow in general, but with some regions in the far south and northeast at orange), and the Civil Protection Agency has activated the Inuncat plan alert.

Temperatures will begin to drop, with lows often recorded late in the day, but highs that will remain virtually unchanged along the coast and will drop more significantly in the Pyrenees and Pre-Pyrenees. It will be between Monday and Tuesday when we will fully notice the significant cooling throughout due to the arrival of cold air from polar origin. We will even have below-average temperatures, with generally quite cool temperatures and possibly the first dusting of the season in the high Pyrenees. Tomorrow night, autumn will officially arrive, and it will enter with a bang.

Sunday: significant change in weather

The approaching cold air pocket will cause a significant increase in instability. This morning, the first showers have already occurred in the Pyrenees and Pre-Pyrenees of Lleida, as well as some weak, scattered showers in some coastal and pre-coastal areas, often barely wetting the ground. In some cases, in the Lleida Pyrenees, storms are already developing with intensity, and storm cores are also visible in the Pre-Pyrenees, Central Catalonia (Osona, Lluçanès), and the Pre-coastal area.

Showers and thunderstorms will gain ground throughout the afternoon and evening and may appear in any region, with some significant downpours accompanied by hail. The highlight of the episode will be the storms that will form starting mid-afternoon between Terres de l'Ebre and northern Castellón, as well as the rain that will affect the eastern Pyrenees and nearby regions, where it will rain heavily for several hours. In these areas, rainfall could easily exceed 30 or 40 l/m2 throughout the day.

A complicated day, and keep an eye on the sky, especially after midday. Mountain activities are not recommended, especially without appropriate clothing, as the relatively mild morning weather will quickly be replaced by cool, even chilly, temperatures at night. Furthermore, this is the weekend return day, so be careful on the roads if you're caught driving in the rain. Early in the morning, we won't notice the change in temperature, but throughout the day the mercury will drop, especially inland and in the Pyrenees, where the coolness will already be evident. Many lows will be recorded at the end of the day.

Monday: Soda is everywhere

By Monday, the front will have passed, but the cold air behind it will still generate cloudiness. A few showers are expected early in the morning in the northeast, the Pyrenees, and the central coast. They will be generally light, although heavy showers may occur early on the central coast. From midday onwards, a few light to moderate showers are expected inland in the Girona regions and the Pyrenees. At midday or during the afternoon, showers may recur on the central or southern coast of the Costa Brava. The snow level will hover around 2,200 m and the atmosphere will be full of autumn in the Pyrenees.

Autumn will begin at 8:19 p.m. with a good general refreshment.

The week will start with a much cooler atmosphere, as temperatures will drop everywhere, with lows close to 5°C in the Pyrenean valleys and between 10°C and 14°C in much of the interior of the country. We will therefore be talking about a very cool and fully autumnal atmosphere on the day we enter astronomical autumn. We will still be doing so with traces of clouds, although clearings will gain ground during the morning. Showers will recur in the northeast in the afternoon, generally more scattered and weaker.

A strong cool breeze next week

Cold air from the polar regions will hit us hard next week. We're looking forward to some much cooler days, more reminiscent of October than mid- to late-September. Starting Tuesday, highs will barely exceed 22 or 23°C, and around 16°C in the Pyrenees, with cold nights in many inland regions and mountain areas, where temperatures will drop below 0°C at high altitudes for the first time in many months. Lows in the Pyrenean valleys will be around 4°C, hovering around 10°C inland and in the West, and around 16°C on the coast. Autumn will begin with a firm start on Monday at 8:19 p.m.