Status:Ongoing analysis Material from: Linus, ..
1. Impact
On 17 -18 September the region south of Bologna was hit by severe rainfall. The synoptic system was linked to Storm Boris (202409 - Rainfall - Central Europe).
2. Description of the event
The evaluation of the rainfall will focus on 48-hour rainfall on 17 September 00UTC - 19 September 00UTC for a 0.25x0.25 degree box south of Bologna (centred on 44.2N, 11.5E).
The plots below show analyses of MSLP and 6 hour rainfall from 15 September 00UTC to 20 September 00UTC, every 12th hour.
The plots below show analyses of T850 and z500 from 14 September to 20 September.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show 48-hour precipitation in observations (first plot, to be added), concatenated short forecasts (second plot)
The plots below show 48-hour precipitation in ENS control forecasts with different lead times.
The plots below show 48-hour precipitation in DestinE 4.4km with different lead times.
The plots below show 48-hour precipitation in AIFS with different lead times.
The plots below show 48-hour precipitation in AIFS0-ENS member 1 with different lead times.
3.3 ENS
The plots below shows EFI and SOT for 3-day precipitation (17-19 September).
The plot below shows the forecast evolution plot for 48-hour precipitation for Vienna (split in two figures to fit all forecast types).
Observation - green hourglass
Analysis - green dot
ENS control–red
ENS - blue box-and-whisker
AIFS - cyan dot
Desint4.4km - evergreen dot
AIFS-ENS - grey box-and-whiske
Model climate – cyan box-and-whisker
Ensemble mean as black diamonds. Triangle marks the maximum in the model climate based on 1800 forecasts.
3.4 Monthly forecasts
3.5 Comparison with other centres
4. Experience from general performance/other cases
5. Good and bad aspects of the forecasts for the event
- Reasonable medium-range prediction for a wet day
- Clear underestimation of the event
- DestinE4.4km seems to improve upon 9-km IFS
- Weak signal in low-resolution AIFS-ENS