Episode 26, 8 December 2021
Analysis
Description
Meteorological background
From 26 November to 12 December, a series of cyclones crossed the Adriatic, influenced by a persistent upper-level trough. On 6ā7 December, the deep cyclone āBarraā formed over the Atlantic, with central pressure dropping to 960 hPa on 7 December. Barra’s frontal system reached Europe on 7 December, triggering leeward cyclogenesis in the Gulf of Lion that night. By 8 December, this cyclone intensified in the Gulf of Genoa before moving towards the Adriatic, while Barra remained over the North Sea, generating strong to gale-force SE winds across the Adriatic.
Sea-level evolution
On 8 December 2021, at 23:00 UTC, sea level in Bakar rose to 97 cm above the long-term average. The sea-level maximum peaked shortly before the daily tidal maximum, which contributed 10 cm. Synoptic component, driven by a Mediterranean cyclone and Atlantic pressure gradient, contributed 46 cm to the overall maximum. Although series of disturbances crossed the Adriatic in period before the flood, no pre-existing wide-basin seiches were triggered. Therefore, synoptic component was mainly driven by a storm surge.
The remaining sea-level rise resulted from processes acting on other time scales (refer to Figure 1 in the Introduction for detailed explanations). Local processes contributed 7 cm, long-period sea-level variability added 18 cm, and mean sea-level changes added 16 cm.
During this flooding episode, all processes contributed positively, with the synoptic component having the largest impact.
Newspaper reports
Here is an excerpt from reports about the flood from Novi list.
Stormy sirocco wind lifts cobblestones and moves cars in the Rab waterfront
RAB >> Waves driven by stormy sirocco wind flooded the Municipium Arba square during the night and water entered stores and restaurants. Some boats ended up on the shore, and in the parking lot on the city shore, near Dorka Park, the force of the sea lifted paving stones and moved cars. Fortunately, workers from the municipal company “Dundovo” had been working since the early morning to remove scattered cobblestones from the road so that it was passable again relatively quickly. Firefighters from the Rab Volunteer Fire Brigade (DVD Rab) were also on site with their pumps to help the owners of the flooded properties. On parts of the Barbat promenade, gravel from the beaches covered the asphalt, and in Grpa, the wind blew down a telephone pole.
Other online articles mention that the strong winds led to the disruption of many ferry and catamaran routes, especially in the central and southern Adriatic. On the island of Rab, many stores and restaurants on the coast were flooded, boats were washed ashore, while the strong surf lifted pressure vessels and displaced cars. In Split, the wind felled numerous trees that fell on vehicles and electricity pylons, leading to dozens of firefighting operations throughout the day.