Fires raged along the Adriatic coast for days in mid-July 2017, causing major destruction in Croatia and Montenegro.
11 October 2022
17 July 2017
By Djordje Gencic (RHMSS), Marko Blaskovic (DHMZ) and Ivan Smiljanic (SCISYS)
On 15 and 16 July a cut-off low, which formed from larger cyclone, travelled across central Europe, before heading towards the Ionian Sea and further east/southeast.
A ridge of high pressure formed over continental Balkan area on the rear side of this cyclone and produced a strong pressure gradient, causing northeasterly winds known as Bora on Croatian and Montenegrin coast.
Although Bora situation aren't unusual in that area they usually occur during colder times in the year.
In the summer the Mediterranean coastal area is usually very dry and often experiences wildfires. Adding high Bora winds to that situation, of dried vegetation and surface soil layers, can cause fires to spread at a much higher pace than usual.
This was the case in July 2017 along the coast, where many wild fires occurred — three of which were particularly large. Two in Croatia, near Split and Benkovac, and one near Tivat in Montenegro.
Fires can usually be seen in IR3.9 imagery as hotspots, while smoke can be seen in shorter wavelengths in the visible part of spectrum, especially over the sea (see Figure 2).
Sometimes, due to very high illumination that fires produce, one can detect those in visible part of spectrum during the night. The Day-Night Band (DNB) image from the Suomi NPP VIIRS instrument, shows fires mixed with city lights (Figure 3).
Smoke from the fires can be nicely seen in the animation of the enhanced Meteosat-10 Natural Colour RGB, during the day, 17 July 03:00–19:00 UTC. Fires are well seen, especially during dawn and dusk due to the scattering geometry (strong forward and backward scattering). Many fires are traceable from smoke visible over Italy on that day.
On the Meteosat-10 High Resolution Visible imagery, 17 July 10:00–18:00 UTC cloud streets in the morning hours and early afternoon over Bosnia and Herzegovina, Montenegro and Serbia clearly show the direction of the blowing wind (Bora wind). At about 12:00 UTC, trails of smoke start to be seen over central and southern Adriatic, clearly illustrating the size and magnitude of these wildfires.