1. Heavy snow impacted Italy and the Balkans with record snows on both sides of the Adriatic. 100.8” of snow fell in 18 hours. Pescocostanzo, Italy – 21 miles away – picked up 94.5”. The WMO will confirm whether the snowfall did indeed surpass the current 24 hour snowfall record (75.8” at Silver Lake, Colorado set in 1921).

2. Capracotta record snowfall setup Due to the terrain near Capracotta, this village is most susceptible to weather coming from the northeast. As noted in the upper air and surface pressure, wind, temperature, and precipitable water (PWAT) patterns attached, this event provided a near-perfect setup for heavy snow. The center of the low pressure system formed to the southwest of the area; resulting in strong northeast winds over the town. These winds channeled high PWAT air over Capracotta and temperatures continued to drop during the event.

3. Italy : the terrain and station location

4. Zoomed In Terrain Near Capracotta terrain favors upslope and funneled winds from northeast

5. The Pattern from the CFSRV2 Climate forecast system re-analysis version 2 500 hPa heights and anomalies  – Deep cut-off low develops over Italy south of affected region Surface  – Secondary cyclone develops south of the region – Surge high PWAT air from south and east of region 850 hPa – Temperatures fell -4 to -6C – Strong northeasterly winds Jet – Strong 250 hPa jet about the close cyclone

6. 500mb Pattern

7. Localized 500mb Pattern

8. Surface Pattern

9. Precipitable Water (PWAT)

10. 250mb Winds

11. 850mb Temps

12. 850 U Winds

13. 850mb V Winds

14. 250mb U Winds

15. 250mb V Winds

16. The impacts Pictures from the web and new outlets – Deep snow – Channels for roads between snow banks – Buried cars – Snow covered ski slopes til June?

17. Source: meteoweb.eu

23. Source: ABC7 WJLA Video – enter slide show mode and click play to view or visit https://www.youtube.com/watch?v=GjsUgauEzVs

24. Source: Telemolise Video – enter slide show mode and click play to view or visit https://www.youtube.com/watch?v=9it3Sge13y0

25. GEFS forecasts Indications of potential heavy precipitation – 24 hours 25 to 75 mm – Localized in Italy and Balkans Pattern well predicted – 500 hPa – Winds – Cold for snow

26. GEFS Probability 25 mm QPF 24 hour period 6-Forecast cycles

27. GEFS Probability 25 mm QPF 24 hour period

28. GEFS mean QPF and each member 75mm or more QPF

29. 500 hPa and anomaly forecasts 18Z 5 March

30. V-wind forecasts

31. U-wind forecasts valid 18Z 5 March

32. 850 hPa temeperatures

33. GEFS forecasts Indicated the pattern and potential QPF was in the general areas of heavy snowfall – Regional area of Italy – Regional area of Balkans Strong 850 hPa winds well predicted – Case model QPF knew where lift was – Regional scale models likely would have focused the QPF and refined forecasts of heavy snowfall which is beyond the skill of a global forecast system.

34. Snowfall map Source: snow-forecast.com 7-day snowfall may from March 5 th to March 11 th, 2015

35. NASA imagery from 10 March 2015, showing the snowfall impact from the event. Source: meteoweb.eu

36. Summary Record snow event for city – Possible but unlikely world record snowfall for 18 hours. Cut-off low for late season snow – Had several signals in the standardized anomaly fields – Strong forcing implies some predictability