Episode 20, 1 November 2012
Analysis
Description
Meteorological background
In the week before the flood, a deep low-pressure system moved over the Adriatic on 27 October. By 31 October, a well-defined surface cyclone with a closed low-pressure circulation in the upper atmosphere formed in the western Mediterranean and traveled toward Italy, with its central pressure dropping to 985 hPa. Concurrently, an anticyclone over the Adriatic weakened and shifted eastward. On 1 November, the cyclone, along with its frontal system, moved over the northern Adriatic, generating strong SE winds. Although the cyclone moved eastward over land, southerly winds persisted over the Adriatic, influenced by MSLP gradients from a large, persistent Atlantic cyclone with central pressure near 965 hPa.
Sea-level evolution
On 1 November 2012, at 06:00 UTC, the Bakar tide-gauge station recorded its highest sea level ever, reaching 113 cm above the long-term average. This peak occurred during the daily tidal maximum, which contributed 23 cm to the total sea level.
The basin-wide oscillations (~21.5 hours) triggered by a disturbance on 27 October had dissipated by the time of the main event. As a result, synoptic component can be considered solely as the storm surge. The storm surge began building on 30 October, driven by a drop in pressure and strong Sirocco winds, which were particularly intense along the eastern Adriatic coast. Synoptic component contributed 39 cm to the total sea-level rise.
The remaining sea-level rise resulted from processes acting on other time scales (refer to Figure 1 in the Introduction for details): local processes added 6 cm, long-period sea-level variability contributed 26 cm, and mean sea-level changes added 19 cm.
In summary, the flood was caused by the combined effects of all contributing processes, with synoptic component having the most significant impact.
Newspaper reports
Here are excerpts from reports about the flood from Novi list and Slobodna Dalmacija.
Novi list, 2 November 2012
In the early hours of Thursday morning, parts of Riva Boduli, Verdijeva, ZagrebaÄka and Demetrova streets, as well as part of the square in front of the Croatian National Theater Ivan pl. Zajc, were found under water, where numerous cases of flooding of commercial premises on the first floor of buildings were recorded. While last weekend a part of the market swam due to heavy rainfall, this time the cause of the flooding was the sea, whose level rose about half a meter above normal, causing the sea water to overflow through the sewage system onto the streets. It is not the first time that the sea has overflowed around the market, but residents and business owners claim that they have not experienced such high water levels for decades.
NAVIGATION IN STORMY WEATHER – TURBULENT VOYAGE OF THE “MARKO POLO” FROM ANCONA TO SPLIT
Five people injured, several vehicles damaged
SPLIT/RIJEKA Five people were slightly injured and several vehicles were damaged on the ferry “Marko Polo” as the ferry was heavily tilted by the waves during yesterday’s stormy voyage from Ancona (Italy) to Split. This was learned from the headquarters of the International and Coastal Lines of Jadrolinija in Rijeka…Upon arrival of the ferry “Marko Polo” from Ancona to Split, some passengers told local media that they had the feeling that the waves would capsize the ship. Due to the strong, at times even gale-force sirocco wind…which at times reached speeds of over 120 kilometers per hour, several ferry services in the Split area were canceled during the night from Wednesday to Thursday.
Slobodna Dalmacija, 3 November 2012
DEVASTATED PELJEÅ AC – A SURVEY OF THE DAMAGE
OrebiÄ: The sea has washed away the road
Cyclone Ladislav, accompanied by gale-force sirocco wind, devastated OrebiÄ and the surrounding settlements on the PeljeÅ”ac peninsula. The sirocco broke off branches, while the tide and waves brought down everything in their path. The Obala pomoraca promenade and the kneza Domagoja promenade, known as the “lower road”, suffered the most damage, and the basements of the first row of houses by the sea were flooded. Damage was also recorded in KuÄiÅ”te and Viganj. – Over a length of 1.5 kilometers, the south wind caused the lower road to collapse, which serves as a state road during the summer months, especially during ferry rush hours – said the mayor of OrebiÄ, Tomislav JurjeviÄ, who was on site with employees of the municipal company “Bilan” and tried to repair the damage.
A hurricane-like sirocco on the island of Vis
Rade PopadiÄ reports that the cyclone “Ladislav” brought strong sirocco wind that raised the sea, broke branches and toppled trees. A wind gust of up to 133 km/h was measured on the island of Vis. In parts of the island, the average speed of the sirocco wind was hurricane force, which corresponds to the wind speed of a tropical storm, and less than 10 kilometers per hour was needed to reach the strength of a category 1 hurricane – according to PopadiÄ.