DANA bautizada por AEMET que provoco lluvias torrenciales (mas de 200 mm/24h) y vientos huracanados en el cuadrante este peninsular.
Inundaciones en Tarragona y Castellon, danos agricolas, cierre de aeropuertos y carreteras.
Aline formed southwest of the Iberian Peninsula and tracked up towards the Mediterranean, a path that in October means an easterly and heavy seas on the Catalan and Valencian coast. What defines it is not the rain but the depth: the pressure it reached off the Tarragona coast is among the lowest of the past thirty years at that point. With the Mediterranean still warm after the summer, that gradient translates into swell that eats beaches and gusts that reach well inland.
The figures that follow are not estimates and have not been copied from any bulletin: they were computed on ERA5, the European Centre’s reanalysis, at a point representative of the area affected — Tarragona — and compared with the 29 complete years of the series. What matters is not the number but the rank.
| Variable | During the episode | Rank in the series |
|---|---|---|
| Minimum pressure | 988.1 hPa | falls in the most extreme 0.1 % of the series of the 254,208 hours measured |
| Maximum 10 m wind | 41 km/h | falls in the most extreme 1 % of the series of the 254,208 hours |
| Rainfall over 4 days | 6.9 mm | does not particularly stand out in the series of the 10,589 4-day windows |
| Minimum temperature | 16.0 °C | does not particularly stand out in the series of the 254,208 hours |
At this point, what was exceptional about Aline was the depth of the low. The other variables stayed within what this place sees with some regularity. To place the rainfall: the wettest 4-day episode recorded at Tarragona in the whole series was 119.3 mm, on 16 November 2013.
ERA5 works with cells of about 28 kilometres and smoothed terrain. It describes the air mass well and allows one storm to be compared with another on the same yardstick, which is precisely what cannot be done with station records that have changed site. What it does not see is the detail: a storm that unloads over one particular ravine is averaged across a cell of 800 square kilometres, and that is why its totals are always lower than those of a well-sited rain gauge. For the official figures of an episode, AEMET is the authority.
Data: ERA5 · Copernicus Climate Data Store, CC-BY licence. Sources and methodology →
