Status:Ongoing analysis Material from: Linus
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1. Impact
During the last days of January north-central U.S and Canada experienced a severe cold spell.
https://www.bbc.co.uk/news/world-us-canada-47088684
2. Description of the event
3. Predictability
3.1 Data assimilation
3.2 HRES
The plot below shows the evolution of 2-metre temperature in Chicago on 31 January in observations (black) and HRES (red) and ENS control forecast (blue). The forecasts were colder than the observations, possibly because the "heat island" of the city is not included in the forecast.
3.3 ENS
The plots below show EFI and SOT for 24-hour mean temperature valid on 31 January.
The plot below shows the forecast evolution of 24-hour mean temperature (based on 6-hourly data) for Chicago . The blue box and whisker shows the ensemble, red dot HRES and red box-and whisker model climate.Already the forecast from 14 January was shifted towards colder conditions.
3.4 Monthly forecasts
The plots below show weekly 2-metre temperature anomaly for 28 January - 3 February. It is worth noting that the temperatures turned warmer in the second half of the week.