Status: Finalised Material from: David L. , Linus


 


1. Impact

Livorno, Italy, experienced heavy rainfall on Sunday 10th September 2017 resulting in six fatalities; a BBC article giving more details is available here. The rainfall predominantly fell between midnight and 2am on Sunday

2. Description of the event

The plot below shows the z500 and t850 analysis from 10 September 00z.

The map below shows the 24-hour accumulations from the local raingauges network around Livorno:


3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The plots below show the 24-hour precipitation between 9 September 06z and 10 September 06z from observations (first plot) and HRES forecasts.


3.3 ENS

The plots below show EFI for precipitation valid 10 September.

The plot below shows the evolution of the ensemble and HRES for 24-hour precipitation in Livorno 9 September 12z to 10 September 12z. The observed precipitation was around 150 mm.

The plot below shows the point-rainfall experimental product for the 98th percentile of the precipitation:


3.4 Monthly forecasts


3.5 Comparison with other centres


3.6 EFAS

The plot below shows the Flash Flood layer from 10 September 00z. The product clearly missed the risk for flash floods around Livorno.



4. Experience from general performance/other cases


5. Good and bad aspects of the forecasts for the event


6. Additional material