Status:Finalised Material from: Linus, Mohamed, Fernando, Ivan

 

Picture

1. Impact

During the first week of November the north-central Mediterranean coast and the southern Alps were hit by intense rainfall and showfall (in the Alps). The situation was caused by a developing trough. Also Morocco was affected by heay rain (see daily reports above).

2. Description of the event


The plots above show analyses of z500 and t850 from 3 October to 9 October. During this period a sharp trough developed and reached northern Africa, bringing a warm and moist stream of air towards the Mediterranean coast and the Alps.


The plots above show the 24-hour precipitation accumulation (ending of the labelled time). During the accumulation ending 4 November 06UTC the south central of France got extreme rainfall. The day after the area around Nice was worst affected together with the south-western part of the Alps and the are around Genua. On 6 November the south Tyrol got a lot of snow and on 7 October Slovenia was worst affected together with the area north of Neapel. 



The plots above show the ongoing alert levels from EFAS where yellow is 2-5 years return period, red 5-20 and purple >20 years.

3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

For the rainfall on 3 Nov 06UTC to 4 Nov 06UTC, the plots below show forecast from operational HRES (cy40r1), e-suite HRES (cy41r1) and experiment with TC1279 (8km) and cycle 41r1. The amount of rain the the worst affected area in France increased with about 20% in the e-suite as expected from the changes in cloud physics. With the increased resolution we find a significant increase for this case.



3.3 ENS




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


6. Additional material