Status:Ongoing analysis Material from:Linus, Fernando
Discussed in the following Daily reports:
Picture
1. Impact
Heavy snowfall occurred in Zealand (Denmark) last Sunday (thanks to Linus). It caused major train delays, traffic congestions and power outage.
2. Description of the event
Heavy snowfall occurred in Zealand (Denmark) last Sunday (thanks to Linus). It caused major train delays, traffic congestions and power outage. The surface analysis show a small scale quasi-stationary cyclone for several hours with an occluded front sitting over the region.
Snow accumulations up to 40 cms were reported in Denmark and S Sweden yesterday at 06Z. The ground was "clear" of snow cover the day before. The amber warning visible in Meteo Alarm web page valid for yesterday seems to be related with the heavy snow.
3. Predictability
3.1 Data assimilation
3.2 HRES
The animation below shows the sequence of HRES 24h acc snowfall forecasts valid for the same date. 1) In general the model tends to underestimate the amounts except in one forecast (Fri 0Z); 2) the best forecast seems to be the run from Fri 00Z (+54h) and 3) surely the forecasters noticed the jumpy behaviour of the latest runs (54, 42 & 30h ) regarding the total accumulations.
3.3 ENS
EFI for snowfall on 21 November:
CDF for point close to Roskilde:
3.4 Monthly forecasts
3.5 Comparison with other centres
4. Experience from general performance/other cases