An extraordinary mesoscale convective system has generated torrential rains, especially in the pre-coastal and central coastal areas, with exceptional amounts such as, for example, the 288 l/m² in Vilassar de Mar, the 255 l/m² in Mataró (Can Canyelles) and the 248 l/m² in Granollers. Ultimately, the medican (Mediterranean hurricane) did not form but, just as the models indicated, the amount of accumulated rain was historic. Notable are the 68 l/m² that fell in just half an hour in Granollers, a figure of extraordinary torrential intensity. The storm system fully affected the Maresme and the Vallès Occidental and Oriental regions. In Pineda de Mar, several rescues were carried out in ground-floor apartments and in vehicles trapped by the water. In the city of Barcelona (Can Bruixa), the record for accumulated precipitation in 24 hours was broken (data since 1914), with a total of 213 l/m².

The red alert remains activated due to the episode of torrential rain in the coastal, pre-coastal and northeastern regions of the country. An extraordinary convective mesoscale system has generated torrential rains, especially in the pre-coastal and central coastal areas, with accumulated amounts until 10 a.m. this morning of 288 l/m² in Vilassar de Mar, 255 l/m² in Mataró (Can Canyelles) or 248 l/m²in Granollers. Ultimately, the medicane (Mediterranean mini-hurricane) did not form, but, as the models indicated, the accumulated rainfall amounts have been historic. Notable are the 68 l/m² that fell this morning in just half an hour in Granollers, a figure of extraordinary torrential intensity. In Pineda de Mar, several rescues were carried out in ground floor homes and vehicles submerged by water, and in the city of Barcelona (Can Bruixa), the record for accumulated precipitation in 24 hours (data since 1914) was broken, with a total of 202 l/m².

In the Mediterranean, a type of atmospheric disturbance can occur that, due to its characteristics, can be associated with a tropical cyclone, although with less intensity and smaller dimensions: the medicanes. The term medicane comes from the fusion of Mediterranean and hurricane. This phenomenon is nothing more than a quasi-tropical depression formed by its own warm core, induced by a large concentration of latent heat resulting from condensation. The energy released by this large storm translates into the formation of large stormy nuclei, with torrential rains, very strong surface winds, and violent phenomena, such as intense electrical activity, waterspouts, tornadoes, and maritime storms. If we observe it through satellite images, it is often accompanied by a kind of eye that resembles, in a certain way, the structure of a hurricane.

Meteocat has activated a red alert –the highest possible– in view of the new episode of torrential rain expected in the coming hours in many counties of the coast, the pre-coastal areas, and the northeast of the country. Precipitation has already started to fall during the morning in the Ebro region, and throughout the day –especially in the afternoon– it will spread to many points of the coast, the pre-coastal areas, and the northern half of the country, with some downpours. It will be towards the night, the early hours, and Sunday morning when the peak of the storm is expected. With current maps, the rains could be intense and extraordinary in the northeast, the coast, and the pre-coastal area of Barcelona, with local accumulations that may exceed 200 or 300 l/m² in a few hours, strong winds, and extreme phenomena. Meteocat's alerts are for intense rain and accumulations of more than 40 l/m² in half an hour, 90 l/m² in three hours, and more than 200 l/m² in 24 hours.

With two days left until the official arrival of astronomical autumn, we still have to talk about temperatures more typical of summer than of these dates. Minimum temperatures have recorded the typical drop in recent days due to the shortening of daily daylight hours, with a significantly cooler environment at night and in the early morning, especially inland and in the Pyrenees. Maximum temperatures, on the other hand, continue to rise. Yesterday they climbed back above 33 ºC in the interior of the Ebro and in the Priorat. And this Monday there will be a heat peak, with many maximums of 30 to 35 ºC throughout the country. Although the mercury will fall back a little on Tuesday, temperatures will remain above average throughout the week, along with anticyclonic calm.

During this weekend and the coming days the weather will be identical, with some exceptions. Temperatures have normalized and only towards Monday will they be able to rise a little in the West. Apart from sun, some morning fog and some thin clouds, the arrival of weak north and northwest winds will stand out, but little else.

Yesterday, remnants of instability were still seen in some sectors of the territory. In the morning, some downpours falling over the sea brushed the coast of Barcelona and left some local showers and, even, some isolated flooding in the seaside neighborhoods of the Catalan capital itself, where in a few minutes more than 10 or 15 l/m² accumulated. They were very local and anecdotal phenomena that ended up clearing away completely.

The nightmare of this atypical and historic heat is numbered. This Monday we will no longer reach 40 °C in the Ponent area, although it will still be very hot. The drop in the thermometer will be slight, around 3 or 4 degrees in some places, enough so that no more records are set. However, it will still be hot, with highs around 38 or 39 °C in Ponent and in the interior of the Ebro. From this Sunday it is worth highlighting new exceptional values, not at all common in the month of September, such as 42.5 °C in Vinebre and 42.3 °C in Torroja del Priorat.

The runaway heat that continues to set temperature records across the country is numbered. This Saturday, the highest maximum for a September since 1914 was once again recorded at the Fabra Observatory, reaching 35.3 °C. With this historic value, there are now four records broken in the city of Barcelona since the beginning of the month. In Ponent, in the interior of the Ebro, and in regions like Priorat, temperatures have reached or neared 40 °C again, with a new September record at 64 of the 128 #XEMA stations with more than twenty years of data.

The unbridled heat continues to set temperature records across the country. This Saturday, the highest maximum for a September since 1914 was recorded again at the Fabra Observatory, with 35.3 °C. With this historic value, there are already four records broken in the city of Barcelona since the beginning of the month. In Ponent, in the interior of the Ebro, and in regions like the Priorat, temperatures reached or brushed against 41 °C, with a new September record at 64 of the 128 XEMA stations with more than twenty years of data.

The unbridled heat continues to set temperature records. Yesterday, Friday, 34.1 °C was recorded at the Fabra Observatory, the highest maximum since 1914 in a September in the city of Barcelona. In Ponent and the interior of the Ebro, temperatures soared again, reaching a sweltering 42.5 °C in Vinebre (Ribera d'Ebre) and up to 39.3 °C in the city of Lleida, the highest maximum in September since 1939. Therefore, it was the hottest September day recorded in Catalonia, with historic values for these dates in 77 of the 128 XEMA stations with more than 20 years of data.

The temperature climbed sharply again, with new records, this Thursday. At the Fabra observatory, it reached 33.1 °C, half a degree less than Wednesday, when 33.6 °C was recorded. Yesterday's value is the second highest since 1914 in a September in the city of Barcelona. In Ponent and the interior of the Ebro, they brushed against 40 °C (39 °C in Vinebre, one of the highest since 2022). If we take the set of Meteocat's automatic stations, 27 out of 128 broke the record for a month of September in 20 years of data, especially those located in Empordà, the Pyrenees, and Ponent.

The temperature rose clearly yesterday Wednesday, when it exceeded 35 °C in many inland points and new heat records were registered in a month of September, as in the case of the Fabra Observatory, where the 33.6 °C measured is the highest value since 1914. All of this is the prelude to an exceptional heatwave that will cause the temperature to be well above the climatic average, with forecasts of registering new temperature records in the coming days.

The Atlantic disturbance located off the coasts of Portugal and Galicia will send a front that will generate unstable weather in our territory this Monday. While the first part of the morning has been stable, from midday the panorama has changed radically and storms have gained ground, affecting a large part of the west and north half by mid-afternoon. Showers of moderate to strong intensity are expected and the possibility of hail or hailstorms in many places, especially in the northern half and the northwest quadrant (you will find a provisional summary of the storms at the end of this article).

Saturday morning thunderstorms discharged strongly offshore and those that hit land left intense downpours. In Baix Penedès, it discharged with great intensity and the showers were torrential. In El Vendrell, for example, they accumulated 146 l/m², 137 l/m² in Torredembarra and 109 l/m² in Calafell.

We are starting a stormy Saturday, but not throughout the territory. Thunderstorms are discharging strongly offshore and are reaching land. In fact, heavy showers and intense thunderstorms are expected between the central coast and the Costa Daurada. These showers will be intense and can accumulate 30 mm in just under half an hour, with significant accumulations, which have already reached up to 100 mm in a few hours. In Baix Penedès, it has discharged with great intensity and the showers have been torrential. In El Vendrell, for example, they have accumulated 129 mm and 113 mm in Torredembarra.

The approach of a cold air trough at high altitude has generated significant atmospheric instability and has already contributed to a drop in temperature. The strong contrast between the cold air at high altitude and the warm Mediterranean mass generated powerful clouds and the storms discharged with force, with some downpours and violent phenomena, such as strong gusts of wind, hail and sleet. The most affected regions were the central coast, the pre-coast and the northeast, with violent phenomena in Anoia, Alt Penedès, Baix Llobregat and the two Vallesos. You can follow the episode at this link:

The change in weather has already arrived, in a radical and even sudden way. The approach of a cold air trough at altitude is causing atmospheric instability to gain ground, and it has already caused the thermometer to drop slightly. In fact, Civil Protection has placed the Inuncat plan on pre-alert this Thursday due to the episode of rain forecast for this Thursday and the coming days. For now, the front has left rain with strong winds and hail, especially in Vallès Occidental, but no significant damage has been reported. In one hour, between 4 PM and 5 PM, the Firefighters received about fifty calls for fallen trees and urban furniture, as well as minor floods.

The heat has ended with the arrival of a cold air mass. Temperatures of 40°C will no longer be repeated and the thermometer will drop, but this will be from tomorrow, with a noticeable cooling in high altitudes and inland, especially on Friday and over the weekend. On the coast, this Thursday, we will still suffer from sultriness due to increased humidity and a cloudier sky.

The heat will still be intense, especially in the interior of the country, where it will exceed 39°C again and could reach up to 40°C in the Lleida plain and the interior of the Ebro valley (and we will already have more than twenty days with such extreme values). The meteorological situation offers no respite regarding temperature due to the warm air mass from North Africa.