WeatherBlog 10 2022/23 | Wild Mediterranean: The Bora

The trough discussed in the last WeatherBlog has broken away and is now buzzing around the Mediterranean as a weather-determining low pressure system. As a result, a lot of precipitation is falling and the Appennines and the Balkan mountains in particular are getting a lot of snow. In contrast, a high pressure bridge has established itself over Central Europe for the time being. This means sunshine and touring weather in the mountains, although high fog below an inversion is to be expected in the valleys with the high pressure. This general weather situation appears to be quite stable and there are no signs of a significant change in the weather for the time being. Only at the beginning of next week will there be signs of the high pressure bridge collapsing due to an incoming cold front. There could be northern congestion and a lot of precipitation on the northern slopes of the Alps, but how much is still in the stars. One thing is certain, however: the next snowfall is sure to come! We continue with an exciting weather phenomenon in the eastern Adriatic region.

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Current general weather situation: Low pressure in the Mediterranean region, high pressure bridge over Central Europe

La Bora a Trieste

Trieste and large sections of the Adriatic coast have been battered by its typical meso-scale wind system in recent days: the bora. This wind belongs to Trieste like the Spritz Bianco or the Jota. The wind speeds in the port of Trieste reached 126 km/h early Monday morning. It was hissing and whistling! But how does this happen? The secret of the bora lies in the special orography of its area of occurrence, given by the Dinaric Alps and the Karst plateau. The most important mechanisms are as follows. The current general weather situation with low pressure in the Mediterranean region and high pressure over Eastern Europe controls the flow from north-east to south-west. The wind is channeled through the valleys of the Dinaric Alps, the gates of the bora, and accelerates as if through a nozzle. However, the highest wind speeds are recorded directly near the coast. In Trieste, the bora drops another three to four hundred meters from the karst plateau and accelerates simply due to its own gravity. The graph shows the maximum and average speed measured by the Molo Bandiera measuring station located directly on the water, as well as the wind direction. The typical north-north-east wind direction can be seen very clearly in the strongest phases of the bora.

The maximum speed of the bora measured so far in Trieste is 183 km/h, measured in February 2012. On such days, public life is reduced to a minimum, but the Triestini are used to their bora and the sidewalks are often equipped with sturdy railings to hold on to. I appreciate the bora for its fresh, invigorating character and the (mostly) sunny skies - the laundry dries in no time even in winter.

The following is the legend of the bora, inspired by Greek mythology, and two films about the bora that are well worth watching for anyone who wants to understand or learn some Italian. Hold on tight please! And hang in there, the next snowfall is sure to come.

The Bora "falls" into the Gulf of Trieste, seen from Strada Napoleonica on 22.01.2023

The legend of the Bora wind

Legend has it that Aeolus, the father of the winds, roamed the world with his beloved children: among them was his favorite child, the young and defiant Bora.

One fine day, they reached a green highland that sloped steeply down to the sea. Bora went off to play with the clouds. After a while, full of curiosity, she went into a cave where she met Tergesteos, an Argonaut who had just returned from the adventure of the "Golden Fleece". It was love at first sight and the young people lived happily in this cave for seven days in ravishing and wild passion.

When Aeolus noticed the disappearance of his favorite daughter, he anxiously decided to search for her. After days of desperate searching, he finally found her lying in the arms of Tergesteos and became so angry that he turned on the man and pushed him violently against the cave walls until he was lying on the ground without life. The father ordered Bora to leave, but the pained woman would have none of it and began to weep so profusely that every tear that fell from her eyes turned to stone.

The tears were so many that the green earth of the highlands was completely covered with a stone mantle. From the drops of Tergesteo's blood, however, sprang the sumac, that wonderful plant that has since bathed the karstic landscape in red in the fall. In the end, Aeolus gave up and decided to leave little Bora in the place where she had seen her great love grow and die. The sea took pity on the poor lover and covered his body with shells, starfish and green algae.

Time passed and a serene hill was formed on which a city was founded, which was named Tergesteos Tergeste, today's Trieste, in honour of Tergesteus. Bora still reigns supreme here today, as heaven has granted her the right to revive her glorious love for three, five or seven days every year: These are the days when Bora blows impetuously, sometimes "clear" in the arms of her beloved sometimes "dark" accompanied by the tears of rain and in anticipation of meeting Tergesteo again.

From the legend of Bora by Edda Vidiz.