Episode 8, 25 November 1969
Analysis
Description
Meteorological background
On 21 November, the Adriatic anticyclone weakened as a deep cyclone formed over the Celtic Sea, accompanied by an upper-level low. During 22–23 November, the cyclone deepened and moved southwest, influencing western and central Europe. This established an upper-level SW flow over the Adriatic and lowered surface air pressure. On 24 November, a new cyclone developed in the Bay of Biscay, moving northeast through France and Germany and deepening to 995 hPa. At the same time, an anticyclone strengthened over the eastern Mediterranean, increasing S and SE winds over the Adriatic, which later shifted to S and SW. During the night of 25 November, another cyclone formed in the western Mediterranean, advancing to the Gulf of Genoa and deepening to 980 hPa as it moved northeast over the northern Adriatic. This caused Adriatic winds to shift temporarily to strong and gale-force SE, turning to strong SW and W winds by evening, particularly in the northern Adriatic.
Sea-level evolution
On 25 November 1969, at 23:00 UTC, the sea level in Bakar rose to 96 cm above the long-term average (Table 2). The sea-level maximum occurred during the tidal rise, with tide contributing just 6 cm. In the weeks before the flood, several low-pressure systems induced basin-wide seiches, but these weakened as a decisive cyclone crossed the Adriatic. The synoptic component, primarily driven by a storm surge, began building on 24–25 November as winds shifted between southwest and southeast. For several days, winds blew more directly toward the eastern coastline, likely causing a stronger sea-level response there. Synoptic component contributed 61 cm to the overall maximum.
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 16 cm, and mean sea-level changes contributed 12 cm.
The flood was driven by the positive contributions of all involved processes, particularly synoptic component.
Newspaper reports
Here are excerpts from reports about the flood from Novi list.
Last night, the hurricane-like south wind raged again throughout the coastal region. The city of Rijeka experienced unprecedented sirocco wind and the sea flooded the passenger port. The damage is considerable. The water penetrated the hotels of Umaška punta. In Rovinj, the research vessel is completely dismembered and already under water. In Opatija, the bathing areas were affected. The waves tore away the concrete base for the slide in Slatina. In Crikvenica, the waves reached several areas of the town and the main square. At the last moment, a fishing boat and an Italian motorboat were rescued in the harbor. From Savudrija to Pag, dozens of boats were flooded. The river Mirna burst its banks near Buzet. Forty Italian fishing boats were rescued in a bay near Pula… Five hundred meters of the coast of Malinska were washed away. In Gorski kotar, strong winds tore the roofs off the houses. In the Potpićan mine, part of the Raša mine, water entered the shafts and hindered production. In Novalja on Pag, the water penetrated all the residential buildings on the coast, and in Pag it penetrated the salt factory. In Oštri, the water destroyed the road, pylons and entered some buildings…
ROVINJ:
BREAKWATER DAMAGED “BIOS” COMPLETELY DISMANTLED
ROVINJ, November 26 — Rovinj also experienced unprecedented bad weather. Strong winds, high swell with waves, lasted from 9 pm until the morning. Dedicated citizens, especially fishermen from the “Mirna” food combine, rescued dozens of boats, cars and several fishing boats from certain sinking all night long, risking their lives. The breakwater of the port of Rovinj was damaged, as was the road along the sea near the “Beograd” cinema to the tobacco factory. The ship “Bios”, which was damaged by the sudden storm on the morning of November 25 and sank in the cargo port of Valtibor in Rovinj due to the force of the waves last night, was completely dismembered. The high swell also penetrated the first floors of many houses, so that a large part of Rovinj lay awake all night. Some boat owners found their boats dry in the morning. The wind did not stop today either. Some old residents of Rovinj, who grew up with boats, claim that they cannot remember such weather and so many hours in a row lasting so long.
Pag: A night of hardship and unforgettable events
WATER DISSOLVED LARGE QUANTITIES OF SALT IN THE SALT PANS
PAG, November 26 — An enormous storm caused severe damage to the population and infrastructure of the island of Pag.
Boats and buildings were threatened by unprecedentedly strong north-westerly wind. While the workers in Pag were still trying to save their property, the first dramatic reports arrived from almost all parts of the island.
In Novalja, the sea penetrated almost all residential buildings on the coast and reached a height of one meter. Several stretches of coastline were destroyed, coastal parks devastated, water and electrical installations damaged and even parts of the asphalt were washed away by the sea. The elemental force also smashed several anchored and moored boats in the harbor….
In the Zaglava area, where several families of cattle farmers live, three boats were smashed, and two fishing boats were severely damaged. The residents of Smokvica also experienced a difficult and unforgettable night in the sea and on the shores of their mooring….
Almost all employees of the Saltworks Collective worked to salvage property, removed machinery and equipment, and even processed and packed salt for transportation, which they only partially succeeded in doing. The flood, which penetrated up to one meter high into the salt warehouses, workshops and social rooms, caused immense damage…. The water dissolved large quantities of salt in the salt warehouses.
Numerous buildings and boats as well as larger ships anchored or moored in the port of Pag were also in danger. The water penetrated almost all buildings on the coast and several boats were damaged.