Naslov
Flash flood in Pula on 25th September 2010

Autori
Mazzocco Drvar, Dunja ; Stanešić, Antonio ; Tudor, Martina ; Ivatek-Šahdan, Stjepan ; Plačko-Vršnak, Dunja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, stručni

Skup
5th HyMeX workshop

Mjesto i datum
Menorca, Španjolska, 17.05.2011. - 19.05.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
flash flood; heavy rain

Sažetak
A case with the extreme precipitation in western part of Croatia during the night from 24th to 25th September 2010 is analyzed by means of measurements and NWP model data. The measurements include satellite, radar, lightning and rain-gauge data, whereas for the forecast part ECMWF and ALADIN models were used. Synoptic analysis showed a deep upper-level trough stretching from western Scandinavia to the Gulf of Genoa with the secondary trough located over Sicily. The low- level synoptic situation was characterized by the south-easterly flow at the front side of a cyclone moving eastwards through the Tyrrhenian Sea transporting warm and humid air along the eastern Adriatic coast. In the afternoon of the 24th scattered showers in the area started. As the warm and moist flow persisted, showers intensified and spread to the whole North Adriatic basin. According to the radar data, the only measurements available over the sea, the hourly precipitation amounts exceeded 50 millimetres. Around midnight of the 25th, second cyclone in the Gulf of Genoa caused the strong convergence along the west coast of Istrian Peninsula. Pronounced vertical wind- sheer induced severe convective development in the vicinity of the horn of Istria moving over the land and producing almost 200 mm of rain in less than 6 hours. In south-western Istria roads and settlements were flooded and the electricity supply was interrupted. The rain-gauge amount of 196 mm is the highest daily value ever measured in city of Pula. Operational 8km resolution hydrostatic ALADIN model forecast the existence of twin cyclones quite satisfyingly giving the correct precipitation maximum over the sea. Nevertheless, there was no indication for the secondary maximum over the Istrian land. The processes that lead to the development of the secondary maximum in the rainfall were further explored using the 2km resolution non-hydrostatic ALADIN modelSeveral experiments using high- resolution model have been performed. The experiment where the prognostic parameterization of convection has been used has indicated the existence of the secondary maximum over the Istrian land.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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