June 2022 saw two serious heatwaves in Europe, during which some all-time temperature records were broken, including for Biarritz in southwest France. The heatwaves were well predicted by ECMWF forecasts.
The month was generally warm in Europe, according to the monthly summary provided by the EU-funded Copernicus Climate Change Service (C3S) run by ECMWF.
According to ECMWF forecasts, more hot weather is predicted for July in western Europe.
Heatwave in mid-June
In mid-June, hot temperatures were concentrated in an area covering much of western Europe.
The Extreme Forecast Index (EFI) is used to indicate the potential for hot weather. EFI values from 0.5 to 1 can be regarded as signifying that unusual weather is likely.
EFI values for temperature on 18 June 2022 in forecasts initialised at 00 UTC on 18 June (left) and 00 UTC on 12 June (right). The hot area was already indicated fairly accurately six days in advance. The hourglass symbol shows the location of Biarritz, France.
The temperature in Biarritz reached record values on 18 June. However, it fell by more than 20 degrees in the same day due to strong winds from the sea, a phenomenon called 'galerna' in the region. The rapid fall was predicted by ECMWF’s 24-hour forecasts.
The black line shows the temperature evolution at a station in Biarritz on 18 June 2022, the red line shows ECMWF’s high-resolution 24-hour temperature forecast for a 9 km wide square, and the cyan lines show ECMWF’s 24-hour ensemble forecasts for an 18 km wide square.
Regarding the prediction of the heat over large parts of France on 18 June, the ensemble forecast gave a strong indication of much warmer temperatures than normal about eight days ahead, as illustrated by the plot.
The plot shows ensemble forecasts (ENS) with various starting dates for an area covering most of southern and central France. The box-and-whisker symbols show probabilities of 99, 90, 75, 25, 10, and 1%. High-resolution forecasts (HRES) are shown as red dots, control forecasts as pink dots, and the analysis as the green dot. The model climate is also shown, as the red box-and-whisker plot, and its maximum is shown as the triangle.
Heatwave at the end of June
Towards the end of June and into early July, another heatwave stretched from northern Africa to the northern tip of Scandinavia.
The plots show the EFI for 3-day 2-metre temperature from 26 to 28 June with a lead time of 0 to 72 hours (left) and 120 to 192 hours (right). The hourglass symbol shows the location of Tromsø.
The plot below shows the forecast evolution for Tromsø, Norway, averaged over three days. It can be seen that the top temperature is about 20°C. This illustrates how the EFI plots show values based on what is locally extreme, rather than absolute values. Regarding predictability, the signal for the extreme values was picked up more gradually compared to the first example, starting between 8 and 10 days before the event.
The plot shows 3-day 2-metre temperature on 26 to 28 June as predicted by successive ECMWF forecasts for Tromsø, Norway, on the starting dates as shown. As before, the box-and-whisker symbols show probabilities of 99, 90, 75, 25, 10, and 1%. High-resolution forecasts (HRES) are shown as red dots, and the analysis as the green dot. The model climate is also shown, as the red box-and-whisker plot, and its maximum is shown as the triangle.
High June temperatures
The heatwaves marked a month which, in Europe, was hotter than usual almost everywhere.
June 2022 was hotter than usual according to this C3S map of temperature anomalies in Europe.
C3S has found that in Europe temperatures were at their second highest for June since 1979. For more details, see the June 2022 climate bulletin of C3S.
More hot weather coming
As of 11 July, another heatwave has already started in western Europe. Watch ECMWF updates of the Extreme Forecast Index and other parameters for further updates.