Status:Ongoing analysis Material from: Linus, Fernando, ...
1. Impact
The windstorm Poly caused severe disruption on 5 July in the northern part of Netherlands. The media mentioned that schools were closed in some regions, air traffic paused and the trains were also affected because of fallen trees in the tracks and overhead wires. 2 dead person is reported (https://en.wikipedia.org/wiki/2022–23_European_windstorm_season#Storm_Poly) and several injuries due to flying debris. The red warning for Netherlands was issued yesterday evening or today after a yellow warning issued yesterday.
2. Description of the event
The satellite images below show the evolution of the cyclone in the morning of 5 July.
3. Predictability
The plot below shows the forecast evolution plot for 24-hour maximum wind gusts (5 July 00UTC - 6 July 00UTC) at Schiphol Airport near Amsterdam. Mean of observations - green, HRES –red, ENS blue box-and-whisker, Model climate – red box-and-whisker. Ensemble mean as black diamonds. Triangle marks the maximum in the model climate based on 1200 forecasts. While some members had extreme wind gusts in forecasts from 30 June-1 July, the ensemble picked up the extreme signal over the last 2 days before the event.
The plots below shows cyclone features coloured by maximum wind speed within 300 km on 5 July 12UTC.