Abstract:
The NCEP CFSv2 and ECMWF hindcasts are used to explore the deterministic subseasonal predictability of
the 850-hPa circulation of a large domain over the Atlantic and Indian Oceans that is relevant to the weather and climate of
the southern African region. For NCEP CFSv2, 12 years of hindcasts, starting on 1 January 1999 and initialized daily for four
ensemble members up to 31 December 2010 are verified against ERA-Interim reanalysis data. For ECMWF, 20 years of
hindcasts (1995–2014), initialized once a month for all the months of the year are employed in a parallel analysis to investigate the predictability of the 850-hPa circulation. The ensemble mean for 7-day moving averages is used to assess the
prediction skill for all the start dates in each month of the year, with a focus on the start dates in each month that are
representative of the week-3 and week-4 hindcasts. The correlation between the anomaly patterns over the study domain
shows skill over persistence up into the week-3 hindcasts for some months. The spatial distribution of the correlation
between the anomaly patterns show skill over persistence to notably reduce over the domain by week 3. A prominent area
where prediction skill survives the longest, occur over central South America and the adjacent Atlantic Ocean.
