The 11th Analysis Report (AR11) of the NWP SAF AMV monitoring has been released and is available from the Analysis Reports section of the AMV monitoring webpages. The analysis reports identify features from the monitoring statistics and document how these evolve over time.
The status of existing features identified in the monitoring has been updated to reflect changes in the past two years. Several new data sets have been added to the monitoring since AR10. The assessment looks at NOAA-21 VIIRS AMVs, and the inclusion of DWD model data. Alongside these new data sets there have been changes in derivation methods including the rollout of NOAA’s enterprise algorithms. The impact of this change on the monitoring has been evaluated. Further investigation for some existing and new features has expanded our understanding of the cause of the difference between the AMVs and the model. These include the MSG positive bias over N. Africa, the positive speed bias in tropics for MSG and FY-2, and differences between Met Office, ECMWF and DWD statistics for Himawari.