Status:Ongoing analysis Material from: Linus,Thomas H,
1. Impact
During the first half of January 'enormous' amounts of snow fell over the northern Alps, and especially Austria was severely affected. A first evaluation of the accumulated fresh snow amount yield, that in some regions this was an event with an return period of 10 to 100 years. It was almost continuous snowfall on the northern side of the Alps from 1st to 15th January. Many villages were cut off, and ski resorts had to be evacuated. Avalanche danger was at the highest level in the most affected areas. Shows depths of around 50-100 cm appeared in valleys in the northern Alps, and up to 300-400 cm at elevations above 2000 m.
https://www.zamg.ac.at/cms/de/klima/news/stellenweise-neuschneerekorde
https://www.zamg.ac.at/cms/de/wetter/news/vorerst-keine-entspannung-der-schneesituation
2. Description of the event
The first plot below shows the snow accumulation from 29 December to 10 January provided by ZAMG (https://www.zamg.ac.at/cms/de/wetter/news/vorerst-keine-entspannung-der-schneesituation). The highest accumulation was roughly in the box of 47-48N, 10-15E.
The plots below show analyses of MSLP and 6-hour precipitation forecasts from 3 to 8 January. The most intense precipitation appeared on 5 January.
The plots below show analyses of z500 and t850 from 3 to 8 January.
The plot below shows the accumulated precipitation (think lines) in observations(black), short forecast (blue) and climatology (grey). Daily accumulation are plotted as thin lines.
3. Predictability
3.1 Data assimilation
3.2 HRES
3.3 ENS
The plots below show the EFI and SOT for 1-day precipitation valid 5 January.
The plots below show the EFI and SOT for 3-day precipitation valid 5-7 January.