The North Atlantic low west of Madeira is likely to pass just off Marseille on Thursday afternoon

Quick answers

As of the Wed 11 Nov 12Z model run · updated Wed., Nov. 11, 10:41 p.m. CET

Where is the North Atlantic low west of Madeira going?

The centre is about 150 kilometres northwest of Madrid, moving northeast at about 75 km/h. The most likely path takes it about 350 kilometres east of Vienna by Friday morning.

When will the North Atlantic low west of Madeira be closest to Marseille?

Most likely Thursday, Nov. 12, around 1 p.m. CET. Across the forecasts the closest pass comes between Thu 10 a.m. and Thu 3 p.m. CET. Most forecasts pass the centre 20–600 kilometres south of Marseille.

What is the chance it passes within 160 kilometres of Marseille?

56%: 6 in 10 forecasts bring the storm’s centre within 160 kilometres of Marseille. Elsewhere: Lisbon 78%, Bilbao 47%, Madrid 39%, Barcelona 32%. Rain, wind and coastal flooding can reach well beyond 160 kilometres from the centre.

How much rain could Marseille get while the North Atlantic low west of Madeira passes?

From Wed 7 p.m. (when the forecast’s rain totals start) to Thu 7 p.m. CET, the end of the window when its centre is closest to Marseille, the middle of NOAA’s 31 GEFS forecasts brings 33 mm of rain and melted snow to Marseille; nearly all bring 13 mm or more and 6 in 10 bring 25 mm or more; 2 in 10 bring 51 mm or more. By Thu 7 a.m., when that window opens, the middle forecast already has 16 mm. That is all the rain in that time, not only the North Atlantic low west of Madeira’s, from one model (GEFS) on a coarse grid; local official forecasts can differ. Marseille: rain and wind this week →

How sure is the forecast?

Path certainty: low. 150 of 185 ensemble forecasts show the storm, and they disagree on where it goes. The forecasts shifted about 60 kilometres east since the previous run.

Do the AI and physics models agree?

Largely, yes. Chance within 160 kilometres of Marseille: AI ensembles (AIFS ENS, AIGEFS) 52%, physics ensembles (GEFS, ECMWF ENS, GEPS) 58%. By model: GEFS 68%, ECMWF ENS 55%, AIFS ENS 55%, AIGEFS 48%, GEPS 52%. By Friday morning the AI ensembles’ middle track is about 70 kilometres east of the physics ensembles’. Both take it to about 987 mb at its deepest.

Will the North Atlantic low west of Madeira become a bomb cyclone?

Unlikely. None of the 185 ensemble forecasts deepen it fast enough to count as a “bomb” (a pressure fall of roughly 24 millibars in 24 hours, adjusted for latitude).

New to these maps? Read how to read a spaghetti map, or see the week’s rain and wind around the world on the globe.