Meteotsunami hits Croatian Adriatic coast – Hvar in shock

Shock among tourists and residents

In the harbor of Stari Grad, waves crashed over the quay walls late in the evening. Flooding also occurred in the lower-lying coastal sections of Zadar. Dalmacija Danas also reported storm surges across the entire Zadar archipelago. Overall, the impacts of the event extended from Istria to the central Dalmatian islands.

Storm and hail accompany the event

The meteotsunami was accompanied by severe thunderstorms and hurricane-force gusts. The weather station of the Croatian Meteorological Service DHMZ measured peak gusts of 32 meters per second on the island of Lošinj – corresponding to the definition of hurricane-force gusts, which are classified as hurricane strength from 32.7 meters per second. This was accompanied by heavy showers and in some cases extremely large hail, as fell in parallel over northern Italy with grain diameters of up to eight centimeters. In Croatia, the storm gusts reached speeds of up to 115 kilometers per hour, according to reports.

According to experts, the cause of the violent water fluctuations is a classic meteotsunami: small, rapid fluctuations in air pressure trigger brief, sometimes strong fluctuations in sea level. The effect is particularly pronounced in long, shallow bays that, as in Stari Grad, are oriented in the direction of the incoming wave – a configuration that concentrates and amplifies the energy.

Warning from the meteorological service DHMZ

The Croatian Meteorological Service DHMZ had already issued a yellow-level warning for parts of the Adriatic before the event. The warning referred to the combination of severe thunderstorms, strong gusts, and an increased risk of sudden water levels along the coast. Given the short lead time, there was hardly any time for many tourists on the beach and in the harbor areas to prepare for the wave.

Damage to harbor facilities or injured persons were not initially reported. However, the incident once again illustrated how vulnerable densely populated coastal sections along the Adriatic are to rapid weather changes. Meteorologists have been observing such meteotsunamis in the Mediterranean for years with growing attention, because the frequency and intensity of the events may change in the course of climate change.

Outlook and consequences for the region

For the coming hours, the DHMZ announced further showers and thunderstorms over the Adriatic. Especially in the well-known tourist areas along the Croatian coast, such as around Hvar, Zadar, and Istria, authorities called on people to avoid the seafront promenades and harbor facilities for the time being. Cleanup work in the affected harbor towns began on Friday morning.