Description

Meteorological background
The period before this episode featured intense cyclonic activity. On 27 November, a surface-based cyclone entered the Mediterranean from north Africa, as the Adriatic anticyclone weakened and temperatures gradually dropped with the eastward shift of an upper-level ridge. The cyclone deepened as it moved toward the Gulf of Genoa, northern Italy, and the Adriatic.
On 29 November, an arrival of cold, unstable air from northwest Europe led to the development of a new cyclone in the Bay of Biscay, with central pressure dropping to 985 hPa. Its frontal system moved into Western Europe, forming another cyclone in the Gulf of Lion. This cyclone advanced rapidly eastward, affecting the Adriatic on 30 November. Meanwhile, the original Bay of Biscay cyclone crossed France, and due to the constant inflow of the cold air within the upper-level trough over western Europe and the Mediterranean, another cyclone formed in the western Mediterranean. This cyclone intensified to 995 hPa near the Gulf of Genoa and moved across northern Italy into the Adriatic.
On 1 December, a ~20 hPa pressure gradient over the Adriatic generated strong Sirocco winds, particularly near the eastern coast. Persistent low pressure, multiple cyclones, and their frontal systems brought days of strong southerly winds and locally heavy precipitation.

Sea-level evolution
On 1 December 2008 at 07:00 UTC, the sea level in Bakar rose to 105 cm above the long-term average. This total sea-level maximum occurred during the daily tidal peak, which contributed 23 cm. The maximum was reached just before the peak of synoptic component, which was partially influenced by pre-existing seiches. Natural basin-wide oscillations, present in synoptic component since 21 November, were sustained by a series of cyclones crossing the Adriatic. These cyclones caused sudden wind shifts, triggering and amplifying the seiches. Given the seiche period (~21.5 h) and the timing of their amplification, it is clear that they contributed to intensifying the flood. The combination of pre-existing oscillations and a storm surge, driven by strong winds over the central Adriatic (with peak speeds near the eastern coast), resulted in a significant synoptic sea-level response of 43 cm.
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 added 9 cm, long-period sea-level variability contributed 17 cm, and mean sea-level changes added 13 cm.

In summary, the flood resulted from the combined contributions of all sea-level processes, with synoptic component being the most significant.