201907 - Heatwave - W. Europe

Status: Finalised Material from: Linus, Mohamed

1. Impact

On 24-25 July a heatwave affected western Europe. National records of temperature were recorded in the Netherlands (Gilze-Rijen station, 40.7C), Germany (Lingen, 42.65C), Belgium (Begijnendijk, 41.8C), Luxembourg (Steinsel, 40.8C) and (provisional) United Kingdom (38.5C, Cambridge Botanical Garden, https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2019/provisional-hottest-day-on-record). The record was also broken for Paris with 42.6C.

https://en.wikipedia.org/wiki/July_2019_European_heat_wave

2. Description of the event

The plots below show analyses of z500 (contours) and T850 (shade) from 22 to 26 July.

The plot below shows the evolution of T850 over north-western France from 1 March to 28 July. The two heatwaves of 2019 stands out with a more normal period in-between.

The plot below shows the maximum temperature observations on 25 July.

3. Predictability

3.1 Data assimilation

3.2 HRES

3.3 ENS

The plots below show EFI and SOT for 3-day temperatures valid 23-25 July in forecasts from 23 July (first plot) to 17 July (last plot).

The ensemble ensemble evolution plot below shows the ENS (blue) and HRES (red dot) 3-day average temperature for a box covering most of France 23-25 July.

The plots below show EFI and SOT maximum temperature valid 25 July in forecasts from 25 July (first plot) to 20 June (last plot). All forecasts captured the heatwave.

The ensemble ensemble evolution plot below shows the ENS (blue) and HRES (red dot) for maximum temperature in Paris on 25 July. Some inconsistencies can be spotted in forecasts from 16-18 July.