Status:Ongoing analysis Material from:Linus
1. Impact
During the two first weeks in September two heatwaves affected Western Europe. In the first week the temperatures in Portugal and Spain reached 44-46C, which broke the September record for Europe. During the heat wave severe wildfires appeared. In the second week a heatwave affected British Isles with the warmest September temperatures in the past 100 year recorded.
2. Description of the event
The plot below shows the time=series of EFI for day 1 as a proxy of the extremity of the analysis of 2-metre temperature for the summer 2016. Among the four cities in the plot (Stockholm, London, Paris, Madrid), the highest values appeared in London and Paris on 13 September. We week before the highest values for the season appeared in Madrid.
The sequence of plots below show analyses of z500 and t850 from 8 to 15 September. The highest temperatures during the first phase were reached on 5-7 September in Portugal and Spain. In the second phase the warmest temperatures on the British Isles were on 13-14 September.
The plot below shows a Howmuller diagram of z500 (zonal anomaly) averaged between 35N and 55N, spanning from 20 August to 20 September.Both heatwaves had a trough over the eastern Atlantic and ridge over Europe bringing warm air northward.
The plot below shows the fire radiative power from the CAMS analysis from 6 September.
3. Predictability
3.1 Data assimilation
3.2 HRES
3.3 ENS
The plots below show 3-day EFI and SOT for 2-metre temperature during Phase 1 (5-7 September). The final plot shows the evolution of forecasts for 2-metre temperature for 5W-0W, 38N-42N for the same period.
The plots below show 3-day EFI and SOT for 2-metre temperature during Phase 2 (13-16 September).
3.4 Monthly forecasts
The plot below shows the verification on temperature anomalies for Phase 1.
3.5 Comparison with other centres
4. Experience from general performance/other cases