Status: Ongoing analysis Material from: Linus, Tim,. .

1. Impact

In the beginning of April western-central Europe experienced a strong cold blast. The cold spell caused problems for vineyards in France for example.

https://www.bbc.co.uk/news/world-europe-56688031

2. Description of the event

The plots below show analyses of T850 and z500 from 3 to 8 April (all 00UTC).

3. Predictability

3.1 Data assimilation

3.2 HRES

3.3 ENS

The plots below show EFI for 2-metre temperature valid 5-7 April. In the forecast from 30 March the cold air was shifted to the west compared to the shortest forecast.

The plot below shows the evolution of 3-day mean 2-metre temperature for Paris on 5-7 April. The plot includes HRES (red dot), ENS CF (purple dot), ENS distribution (blue) and model climate (red). The forecast from 29 March was problematic and related to a large-scale forecast bust.

3.4 Monthly forecasts

The plots below show the weekly mean anomaly for 2-metre temperature 5-11 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