Status:Ongoing analysis Material from: Esti, Rebecca


 

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1. Impact

Extreme widespread forest fires and very high ozone levels, mainly in Spain, Portugal and France. Check this page for more information European wildfires: July 2022 and European ozone pollution: July 2022

2. Description of the event

We can see from the synoptic analysis that the main cause of this heatwave in western Europe was the advection of warm air from North Africa, which was assisted by a quasi-static cut-off low located off the coast of Portugal. After moving northeastward on the 19th and 20th of July, the cut-off low brought some colder air and precipitation to western Europe.

The plots below show analyses of z500 and T850 from 10 June to 19 July

The highest 2-metre minimum and maximum temperatures in the period 17-20 July are displayed on the plots below:

The evolution of 2-metre minimum and maximum temperature anomalies and extremes (red symbols temperature exceed 99th percentile of 20-year climatology) are shown below:

The plots below compare the heat stress (ERA5 UTCI) for this event to 1991-2020 UTCI ERA5 climatology:

Daily max of the hourly ERA5 UTCI, for 18,19,20 July 2022:

Difference between daily max ERA5 UTCI, and mean of the daily max July values 1991-2020, for 18,19,20 July 2022:

Difference between daily max ERA5 UTCI, and 100th percentile of hourly UTCI values in July 1991-2020 (max in historical record), for 18,19,20 July 2022:


3. Predictability

Below we can find some forecast evolution plots for the European records registered on the 19th of July 2022 for 2m maximum temperature. CDFs are plotted for Coningsby  and Northolt (UK) and the forecast evolution slides are referred to Heathrow (UK) and Bilbao (Spain)

 

Below we can find some forecast evolution plots for the European records registered on the 19th of July 2022 for 2m minimum temperature. CDFs are plotted for Aberporth and Kenley (UK) and the forecast evolution slides are referred to them as well, in the same order. 

3.1 Data assimilation

 

3.2 HRES

Mean error of the UTCI HRES forecasts of the daily maximum UTCI for the period 17-20 July 2022, at lead times 1 day and 5 days ahead, compared to ERA5:

(e.g. right plot is the mean of the error in the daily max UTCI for the forecasts produced on 12th July valid 17th, 13th July valid 18th, 14th July valid 19th, 15th July valid 20th)


UTCI HRES forecast errors, compared to ERA5, for the maximum UTCI on 19th July 2022 (regardless of timing) at 1, 5 and 7 days ahead:

3.3 ENS

Below we can see the EFI for 2m maximum temperature valid on the 19 July 2022 and at lead times day 1, 3, 5 and 7. 


Below we see :

ENS probabilities of exceeding 35 degrees in 2 consecutive days (valid on 18-19 July 2022). A sequence of plots every 24h from 00-48h to 312-360h. 
ENS probabilities of exceeding 35 degrees in 2 consecutive days (valid on 18-19 July 2022). A sequence of plots every 24h from 00-48h to 192-240h. 
ENS probabilities > 99 percentile of model climate in 2 consecutive days (valid on 18-19 July 2022). A sequence of plots every 24h from 00-48h to 168-216h. 


Below are example UTCI forecasts for probability of different categories of heat stress, at 7 days ahead of 19th July:

And the same for 1 day ahead of 19th July:



3.4 Monthly forecasts

2m temperature weekly anomalies for week 1, 2, 3, 4 and 5 and valid on the week from 18 to 25th July




Verification plots of weekly mean temperature anomalies and the EFI/SOT are shown below:

3.5 Comparison with other centres


4. Experience from general performance/other cases


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

In general, very good predictability even 15 days in advance, however maximum temperatures were in general slightly underestimated and there were larger errors in the 2m minimum temperature. 


6. Additional material