Status:Ongoing analysis Material from: Ervin, Linus

Discussed in the following Daily reports:

http://intra.ecmwf.int/daily/d/dreport/2016/01/19/sc/

http://intra.ecmwf.int/daily/d/dreport/2016/01/20/sc/

http://intra.ecmwf.int/daily/d/dreport/2016/01/21/sc/

http://intra.ecmwf.int/daily/d/dreport/2016/01/22/sc/

Picture

1. Impact

On 22-24 January a severe blizzard hit the U.S east-coast and broke records in accumulated snowfall in several places. The ammount was only mm from the record in Central Park (NYC) and broke the record on JFK. For Washington DC (Dulles) it ranks as the 2nd worst snowstorm. After the cyclone New Jersey was hit by coastal flooding.

https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/01/24/snowzilla-makes-history-from-northern-virginia-to-new-york/

2. Description of the event

3. Predictability

3.1 Data assimilation

3.2 HRES

3.3 ENS

3.4 Monthly forecasts

3.5 Comparison with other centres

4. Experience from general performance/other cases

201401 - Snowstorm - North-eastern U.S.

201402 - Snowstorm - US east-coast

201501 - Snowfall - US east coast

5. Good and bad aspects of the forecasts for the event

• Early signal (from Sunday 17 Jan 00z)
• Too low accumulation over NYC
• Question about snow density for the case

6. Additional material