Episode 6, 4 November 1966

Analysis

Description

Meteorological background

On 3 November, air pressure over the Adriatic began to drop as the influence of an anticyclone from northeastern Europe weakened, due to an approaching surface cyclone from the western Mediterranean. This cyclone was linked to an upper-level trough with a closed low positioned slightly to the west. By 4 November, the cyclone affected the Adriatic, with its center moving over the northern Adriatic, causing a pressure drop to 995 hPa before continuing northeast. Meanwhile, the anticyclone to the east created a pronounced pressure gradient over the Adriatic. This set the stage for SE winds on 3 November, which gradually intensified. By the morning of 4 November, the winds reached strong to gale-force levels, shifting to SW in the afternoon as the cyclone moved northeast.

Sea-level evolution

On 4 November 1966, at 12:00 UTC, the sea level in Bakar reached 94 cm above the long-term average, followed by a second peak of 92 cm at 20:00 UTC. The first peak occurred after the daily tidal maximum, with synoptic component still building up, and tide contributing 9 cm. In contrast, the evening peak coincided with synoptic component’s maximum, while the tide, in a negative phase, contributed -19 cm. Synoptic component was an isolated storm-surge event with no pre-existing seiches. Storm surge was driven by a strong, sustained Sirocco wind blowing along the Adriatic for over a day, accumulating water into the basin’s closed end. It contributed 48 cm to the first peak and 63 cm to the second.

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 3 cm to the first peak and 15 cm to the second, long-period sea-level variability added 14 cm, and mean sea-level changes accounted for 20 cm.

The first peak was the result of a combination of all contributing processes, while the second peak was primarily driven by a significant synoptic component, along with positive contributions from all other processes except the tide.

Useful links:

La cronaca dell’ Aqua “granda”

Le acque alte eccezionali

Newspaper reports

Here are excerpts from reports about the flood from Novi list.

LIGHTHOUSE CREW MOVES TO THE TOP OF THE LIGHTHOUSE – DOZENS OF BOATS AND SAILBOATS DESTROYED IN THE BAYS OF PULA – 110 KM/H WINDS TOPPLE CENTURIES-OLD SHIPS AND PINE TREES IN THE STREETS OF PULA – DINGHY WITH TWO FOREIGN TOURISTS DISAPPEARS IN THE SEA OFF ROVINJ – LARGE WAVES CAUSE CONSIDERABLE DAMAGE IN UMAG AND OTHER PLACES ON THE WEST COAST OF ISTRIA

SEA FLOODS OF THE DAMS IN ŠTALIJE

LABIN, November 4 – A severe storm is raging over the Labin area, especially in Štalije and Rabac. In Štalije, the seawater breaks through the main dike, and by 7 pm about 70-80 hectares are under water. Nothing has been done so far. The water level rises and exceeds the dike by 40-80 cm. The height of the waves is between four and five meters.

In Rabac, not only have several boats been broken and some flooded, but the seawater has also flooded part of the campsite and the strong sirocco has damaged the terrace and attic of the hotel “Sv. Andreja” hotel. A state of emergency was declared in Labin, Rabac and Štalije.

There has not been such a strong sirocco here in the last ten years.

ZADAR: The ship “Kolega” thrown onto a reef

Yesterday evening, near the island of Ošljak, in the Zadar Channel, the 12 meter long motor vessel “Kolega” sank. There were 20 people on board at the time of the accident. A strong sirocco had thrown the ship onto an underwater reef. The 65-year-old Jakica Šarin from Kali drowned in the accident.

The ship was carrying farmers from Kali to harvest olives on their land in the Zadar area. The accident happened just as they were approaching their destination.

BILLIONS IN DAMAGE IN UMAG AND NOVIGRAD

Seven families evacuated – Vladimir Gortan promenade in Umag destroyed – Many commercial properties severely damaged

According to initial estimates by the commissions, the damage will reach up to one billion German marks. The road between Umag and Savudrija is the most severely affected and has been damaged. The Vladimir Gortan promenade is almost completely destroyed, with some sections completely washed away, leaving holes several meters wide. In addition, the warehouse and administrative building of the “Industrogradnja” company were completely flooded and ruined, with some machinery also affected. The companies “Jedinstvo” and “Mirna” from Rovinj also suffered considerable losses. Beaches, cafes and restaurants as well as many houses in the old town of Umag, were impacted, leading to the evacuation of seven families for safety reasons.

ADRIATIC STORM SURGE CATALOGUE