Status:Ongoing analysis Material from: Linus, Margarita Choulga
Picture
1. Impact
On 23-24 August heavy rainfall hit eastern Latvia and western Russia. The rainfall in some cities was record breaking with almost 25% of the annual precipitation in 1-2 days. The rainfall seems to have been due a semi-persistent front connected to a Vb cyclone.
2. Description of the event
The plots below show short forecasts of MSLP and 12-hour precipitation from 22 August 12z to 24 August 12z.
The plot below shows 2-day (?) accumulated precipitation from 23 August 00z to 25 August 00z, provided from the Latvian Met Service.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show HRES forecasts of precipitation from 23 August 12z to 24 August 12z and MSLP at 24 August 00z from different initial times starting from the latest forecast.
3.3 ENS
The plots below show 3-day EFI for precipitation valid 23-26 August.
The plot below shows the evolution of the ensemble forecast (blue) and HRES (red) for 24-hour precipitation (23 Aug 12z-24 Aug 12z) for Rēzekne in eastern Latvia. Observation was around 145 mm.
3.4 Monthly forecasts
3.5 Comparison with other centres
3.5 EFAS
The plot below show the flash flood warnings from EFAS.
4. Experience from general performance/other cases
5. Good and bad aspects of the forecasts for the event
- Reasonable signal in 1-2 days before the event, very weak before