Summary
A special case of convective development, following the so-called train effect, in which intense convective cells form over the same place in a short period of time, is presented here. This regime produces large amounts of rainfall and flash floods. At the Rijeka meteorological station, the 3-hourly precipitation amount was 135.9 mm and the 24-hour precipitation amount measured by the rain-gauge (287.5 mm) was the highest on record for that station.
A yellow warning for severe thunderstorms for 'Rijeka region' (Istria, the northern Adriatic coast and islands) was issued on September 28 for the afternoon and night. An orange warning for heavy rain was issued for September 29, although the bulk of the precipitation fell on the 28th.
Figure 17: Meteoalarm weather warnings for Croatia: for September 28 (left - thunderstorm) and 29 (right - thunderstorm, heavy rain, wind).