Status: Finalised Material from: Ivan, Linus


 


Picture

1. Impact

In the week of 17-23 April a unseasonal cold spell hit large part of Europe. Already the weekend before was cold in Scandinavia, and during the cold spell snowfall hit central-eastern Europe and problems with frost in vineyards across Europe.

2. Description of the event

The plots below shows the sequence of analyses of z500 and t850 from 15 to 24 April.


3. Predictability

  

3.1 Data assimilation

 

3.2 HRES


3.3 ENS


The plots below show the prediction of snow fall in Poland on 18 April.


The plot below shows EFI for snowfall on 19 April, together with the snow analyses from 19 and 20 April indicating the accumulations on 19 April.



The plot below shows the evolution of forecasts for average 2-metre temperature over Germany 17-20 April. The ensemble converged on 14 April to the cold conditions.


3.4 Monthly forecasts

The plots below show the weekly 2-metre temperature anomaly for 17-23 April.




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