Status:Ongoing analysis Material from: Linus, Esti
1. Impact
On the 5 October a small-scale cyclone brought strong wind gusts over the Netherlands and northern Germany, causing a few fatalities and travel disruptions.
2. Description of the event
2.1 Broadscale
The plot below shows an animation of MSLP and precipitation from HRES, with a small-scale cyclone developing over northern Germany.
Following a period in the developmental upper jet right entrance region, the most rapid cyclogenesis occurred as the upper level jet axis was crossed, . The plots below of 300mb isotachs and mslp, from the Met Office global model, illustrate this process. Rapid development during jet-crossing is quite common.
The plot below shows the warnings on Meteoalarm from 5 October, with a red warning for wind gusts over northern Germany.
2.2 Mesoscale
Satellite and radar sequences around the time that the maximum gusts hit Berlin both suggest, via filamentation in the cloud head region, that the gusts could well have been due to the "Sting Jet" phenomena. The fact that the gusts inland were so high is also believed to be a characteristic of sting jets, because of the top-down destabilisation mechanism that is believed to be involved (as on the 3D poster below).
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show the 24-hour maximum wind gusts from HRES for 5 October and MSLP valid 5 October 12z. The first plot shows 24-hour maximum wind gusts from observations.
3.3 ENS
The plots below show the EFI and SOT for 24-hour wind gusts valid 5 October.
3.4 Monthly forecasts
3.5 Comparison with other centres
4. Experience from general performance/other cases