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3. Predictability
3.1 Data assimilation
The animation below shows the observation rejection (low weight) charts for subsequent assimilation cycles. Wind observations with low weight is marked with symbols and the 250 hPa wind speed in the analysis is plotted with shades. The position of low A is marked with a black dot. On 23-24 December a cluster of observations were given low weight over U.S, probably connected to severe convection.
3.2 HRES
The plots below shows the accumulated precipitation between 25 Dec 06z and 26 Dec 06z.
O-suite:
E-suite:
The plots below shows the accumulated precipitation between 26 Dec 06z and 27 Dec 06z.
O-suite:
E-suite:
3.3 ENS
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5. Good and bad aspects of the forecasts for the event
- Early signal in monthly (and seasonal forecasts) for a wet anomaly in December
- Problems with the details of the cyclone development on 25-26 December led to errors in the precipitation pattern also in the short-range (>24h)
- Underestimation of the magnitude of the precipiation in both o-suite and e-suite