Status: Ongoing analysis Material from: Linus, Bojan
1. Impact
On 4-5 November severe rainfall hit Bosnia and resulted in floodings.
Floodlist entry: https://floodlist.com/europe/bosnia-floods-november-2021
2. Description of the event
The plots below show analyses of z500 (contour) and T850 (shade) from 31 October 00UTC to 6 November 00UTC, every 24 hour. On 3-4 November a deep trough developed over western Mediterranean bringing moist air towards central Italy and the Balkans.
The plots below show analyses of MSLP and 6-hour precipitation forecasts from 2 November 00UTC to 6 November 00UTC every 12h.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show observations from SYNOP (first plot) and HRES forecasts of 72-hour precipitation valid 3 November 00UTC - 6 November 00UTC, from different initial dates. The highest observation is found in the mountains south of Sarajevo with 150mm/72h.
3.3 ENS
The plots below show EFI for 3-day precipitation 3-5 November, from different initial times.
The plots below show EFI for 3-day integrated water vapor flux 3-5 October, from different initial times.
The plot below shows the forecast evolution plot for 72-hour precipitation valid 3 November 00UTC - 6 November 00UTC for the 1x1 degree box over south-eastern Bosnia. The forecast values are average of the observation positions as seen in the map under HRES sub-section above. Mean of obs - green, HRES –red, ENS - blue box-and-whisker, Model climate – red box-and-whisker. Triangle marks the maximum in the model climate based on 1200 forecasts.
3.4 Monthly forecasts
The plots below show weekly anomalies of precipitation for 1-7 November from different initial dates. The extended-range forecast from 25 October was the first to pick up the wet signal.
The plots below snow the same as above but for z500 anomalies. The capturing of the precipitation signal in the plots above was connected to the prediction of the trough over Western Europe, that brought moist air towards the Balkans.
3.5 Comparison with other centres
72-hour precipitation from 3 November 00UTC for models participating in SEE-MHEWS-A. IFS (1st), Aladin (2nd), ICON (3rd) and NMMB (4th). All models are initialised from ECMWF analysis.
