IPMA forecasts strong rain for mainland Portugal and Madeira from Friday, 6 November

A change in weather from Friday

The Instituto Português do Mar e da Atmosfera (IPMA) expects mainland Portugal and Madeira to see a change in weather from Friday, 6 November, with rain that will sometimes be heavy but temperatures that stay mild. Before that, Wednesday, 4 November, is forecast to bring clear or lightly cloudy skies and strong night-time cooling, with temperatures close to 0 degrees Celsius in the north-east of the Trás-os-Montes region and the Beira Alta. In a statement, the IPMA said the warm spell that pushed November temperatures above average is coming to an end, with polar air arriving from the interior of Europe. From Tuesday, 3 November, maximum temperatures are expected to range roughly between 17 and 22 °C across most of the territory, while minimums of 5 to 9 °C are forecast, falling to between -2 and 4 °C in the interior north and centre, and the gradual cooling continues until Thursday, 5 November.

Polar air gives way to Atlantic air

Meteorologist Maria João Frada said the polar air over the mainland will be replaced by tropical air from the Atlantic, linked to an upper-level depression that will sit west of the continent from Friday and is expected to stay there through the whole following week. She added that maximum temperatures will rise slightly on Friday as cloud and precipitation arrive with the Atlantic air mass.

“It is out there to the west of the territory and will bring precipitation that on some days will be sometimes heavy, with thunderstorms.”

Frada also said the first episode of strong or sometimes strong precipitation this season will probably lead the IPMA to issue a precipitation warning. She noted that October passed without a single episode of strong rain, which is usual in its second half, so November is expected to look different.

Storm of Atlantic origin and wider rainfall

Filomena Martins said the weather models agree on a region of low pressure over the Atlantic, with a deep storm approaching Portugal that is fed by a large atmospheric river and could bring intense rain and strong wind. She said the system would be named Bruna if it receives a name, which she considered the most likely outcome, and that the IPMA would be the body to name it. Several depressions may move close together and interact, keeping the unstable weather in place for many days. Meteored Portugal said the rain could accompany the country for several days, with a quite deep depression possibly approaching the Iberian Peninsula early in the week of 9 November.

Timing of the rain

Rain is expected to reach the west coast from the afternoon of Friday, 6 November, and then spread gradually to the rest of the interior, mainly the north and centre. Forecasters flagged Saturday, 7 November, as the day when the storm picture starts to merit close attention, with the period of greatest concern running from Sunday, 8 November, to Tuesday, 10 November. Meteored Portugal expects the rain to continue through the weekend and last until 13 November, which would follow several weeks in which rain was scarce. The timeline below sets out the forecast beats as they were published.