Even with similar forecasts for a La Nina, ECMWF and UKMO give quite different precipitation patterns over Europe for DJF, with ECMWF being dry over Poland and wet in southern Europe while UKMO is wet in central and northern Europe. The difference is enhanced by the UKMO NAO-based product.
But even when using the relatively dry ECMWF forecast for Poland, the EFAS and SMHI hydrology models’ discharge for the region is high due to the wet initial conditions and a long sensitivity from the initial conditions. If the discharge forecast was driven by the UKMO atmosphere the result would probably be more severe.
Dry soil in southern France and Spain. Poland is initially very wet initially. Basins with long hydrological memory as seen in the sensitivity analysis.
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Emerging La Nina
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Consistent La Nina for both models. Teleconnection to NAO+ for the end of the season.
Teleconnection to NAO+ for the end of the season.
Teleconnection to NAO+ for the end of season.
ECMWF Seas5 is dry for Poland while UKMO is wet.
Long hydrological memory in eastern Poland.
Clear north/south gradient in precipitation due to NAO+. ECMWF Seas5 is not dry for Iberia while UKMO seas and precipitation product are.
High discharge in Poland due to wet initial conditions.
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Dry soil in southern France and Spain. Poland is initially very wet initially. Basins with long hydrological memory as seen in the sensitivity analysis.
Emerging La Nina.
Consistent La Nina for both models. Teleconnection to NAO+ for the end of the season.
Teleconnection to NAO+ for the end of the season.
Teleconnection to NAO+ for the end of season.
ECMWF Seas5 is dry for Poland while UKMO is wet.
Clear north/south gradient in precipitation due to NAO+. ECMWF Seas5 is not dry for Iberia while UKMO seas and precipitation product are.
Long hydrological memory in eastern Poland.
IHC (green), SCF (blue).
La Nina predicted.
La Nina predicted
NAO+ for the end of the season.
NAO+ for the end of season
High discharge in Poland due to wet initial conditions.
High discharge in Poland, forced by “dry” ECMWF forecast.
Autumn melting of snow (or precipitation as rain) causing a high discharge anomaly in Russia?
