Episode 13, 10 December 1990
Analysis
Description
Meteorological background
The period before the flood was characterised by passages of low air-pressure systems above the Adriatic. In the week leading up to the flood, a deep upper-level trough moved from northern Europe to the Mediterranean, supporting southwest flow that carried warm, humid air. On 8 December at 18:00 UTC, a cyclone formed over Spain and moved eastward, reaching the Gulf of Genoa by 9 December afternoon. As the cyclone deepened, air-pressure gradients increased, strengthening south and southeast winds over the Adriatic, particularly along the eastern side. During the night of 9ā10 December, Sirocco winds peaked, coinciding with the extreme sea level recorded in Bakar on 10 December at 02:00 UTC. As the cyclone moved slowly across the Adriatic, the wind weakened and shifted to southwest, progressing from the northern to the southern Adriatic.
Sea-level evolution
On 10 December 1990, at 02:00 UTC, the sea level in Bakar rose to 91 cm above the long-term mean. The tide, with a diurnal neap-tide character, peaked at the same time, contributing 20 cm to the total maximum. In the days before the flood, weak low-pressure systems crossed the Adriatic but did not generate significant basin-wide oscillations (~21.5-h). Therefore, synoptic component was dominated by a storm surge, peaking at 55 cm. The total sea-level maximum occurred 4 h later, during the tidal peak, as the storm surge receded, with the synoptic component contributing 42 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 had minimal impact, adding only 1 cm, long-period sea-level variability added 21 cm, and mean sea-level changes contributed 13 cm.
In summary, this flood was driven by the positive contributions of all involved processes, particularly the synoptic component, long-period processes, and tide.
Newspaper reports
Here are excerpts from a report about the flood from Novi list, Slobodna Dalmacija and VeÄernji list.Ā
CRIKVENICA – During the night from Sunday to Monday, a strong sirocco flooded the center of Crikvenica. The sea rose so high that it flooded the area around the bus station and the large municipal parking lot, and the seawater mixed with rainwater reached the thresholds of parked cars and even the thresholds of the entrances to nearby family and residential buildings. For example, it was impossible to enter the post office through the main entrance from the southwest, and bus services and road traffic in this part of the street “Petak” were disrupted. Many boats were filled with sea water and rain, and some were damaged by the strong sirocco. Such a strong sirocco, which caused such flooding of the Crikvenica coastline, has not occurred for a long time.
Islands in the Dark
ZADAR, December 11 – The stormy sirocco, which has not spared the Zadar region and northern Dalmatia in the last four days, has left devastation in its wake. For example, the islands of Molat, Ist, Olib, Silba and Premuda were without electricity for three days until 2 p.m. today because the main power line to these islands had failed due to the storm. Workers from the Zadar branch of the Croatian Electricity Company were constantly on site, as the overhead lines were broken in several places in the area. All installations have been repaired and as we report this, only the aforementioned island areas are still without electricity. The wind also caused damage to the overhead telephone lines, especially near Nin, Privlaka, Vir, Vrsi and other settlements, but PTT staff were quick on the scene and were able to repair the damage. Sea waves have damaged several port facilities on the islands and the coast, but the extent of the damage will be determined later. Several boats that were in less sheltered areas were also damaged by the storm
Hurricane in the Neretva valley
METKOVIÄ – An unprecedentedly strong sirocco wind, accompanied by rain, caused considerable damage to households, industry and agriculture yesterday. A large tree fell in front of the “Narona” hotel in the city center and damaged three cars. Trees were uprooted and power lines were cut in parks, in the courtyard of the “Edvard Kardelj” elementary school, at the “Norin” company and in the city park. A tree fell on a house in Prvoboraca Street, destroying the roof, and only a few houses were spared water, either through the roof or the walls. Traffic was obstructed by fallen trees on the roadsā¦