1. The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 7 November 2011 For more information, visit: http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/American_Monsoons http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/American_Monsoons

2. Outline Highlights Recent Evolution and Current Conditions NCEP/GFS Model Forecasts Climatology

3. During the last 7 days, below-average rainfall was observed over northwestern and southeastern South America especially western and southeastern Brazil. Above-average rainfall was observed over northeastern South America. For 7-13 November, above-average rainfall is predicted for northern and northeastern South America, southern Peru, and eastern Argentina. Below-average rainfall is predicted over southern Colombia, northern Peru, and western and southern Brazil (except its extreme southern portion). For 14-20 November, above-average rainfall is predicted for northeastern South America, southeastern Brazil and southern Peru. Below-average rainfall is predicted over northwestern South America, northern Argentina, and extreme southern Brazil. Highlights

4. Rainfall Total & Anomaly Patterns: Last 7 Days During the last 7 days, below-average rainfall was observed over northwestern and southeastern South America especially western and southeastern Brazil. Above-average rainfall was observed over northeastern South America. TotalAnomaly

5. Rainfall Totals & Anomaly Patterns: Last 30 Days During the last 30 days, below-average rainfall was mainly observed to the west of 60W, except for portions of Colombia and Bolivia. Above-average rainfall was found over northeastern South America. TotalAnomaly

6. BP Recent Evolution: Rainfall Last 90 Days BP: Brazilian Plateau 90-day rainfall totals are clearly below average over the southern Amazon basin. Below-average rainfall has also been observed over the Brazilian Plateau. 90-day totals are near average in southern Brazil.

7. Tropical Pacific and Atlantic SST Anomalies Below-average SSTs are present in the tropical Pacific Ocean, and above-average SSTs are found in the tropical Atlantic. (For more details concerning El Niño – La Niña go to the link below.) A weekly PowerPoint summarizing the ENSO Cycle: Recent Evolution, Current Status and Predictions is available at: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/enso.shtml

8. Atmospheric Circulation Recent 7 days Rising motion (negative omega, yellow/red shading), usually associated with wetter- than- normal conditions. Sinking motion (positive omega, blue shading), usually associated with drier-than-normal conditions. Upper panels: During 29 October – 4 November 2011, in the upper troposphere an anomalous cyclonic circulation (center at C) was located near the coast of southeastern South America. Lower panels: Anomalous rising motion (negative omega) was found over northeastern and west-central South America, and anomalous sinking motion was observed over southeastern South America. C

9. 925-hPa Wind &Temperature Recent 30 DaysRecent 7 Days Low-level (~600 m) wind and temperature anomalies based on the NCEP Climate Data Assimilation Systems (CDAS) analysis. The patterns of anomalous temperature and wind at 925-hPa are usually similar to surface observations. Note: Areas with surface pressure below 925-hPa are masked out. During the 7-day period from 29 October to 4 November 2011, below-average temperatures were observed over southeastern South America.

10. NCEP/GFS Model Forecasts Bias-Corrected Precipitation Total Forecasts from 31 Oct 2011 – Days 1-7 Anomaly Note: Note: Bias correction based on last 30-day forecast error.

11. NCEP/GFS Model Forecasts Bias-Corrected Precipitation Total Forecasts from 31 October 2011– Days 8-14 Anomaly Note: Note: Bias correction based on last 30-day forecast error.

12. For Days 1-7 (7-13 November), above-average rainfall is predicted for northern and northeastern South America, southern Peru, and eastern Argentina. Below-average rainfall is predicted over southern Colombia, northern Peru, and western and southern Brazil (except its extreme southern portion). For Days 8-14 (14-20 November), above-average rainfall is predicted for northeastern South America, southeastern Brazil and southern Peru. Below-average rainfall is predicted over northwestern South America, northern Argentina, and extreme southern Brazil. NCEP/GFS MODEL FORECASTS

13. Forecast Verification Forecast from 25 Oct 2011 Valid 1-7 Nov 2011 Forecast from 31 Oct 2011 Valid 31 Oct – 6 Nov 2011 Observed 31 Oct – 6 Nov 2011

14. Climatology Rainy Season Dates ONSETDEMISE

15. Precipitation Climatology

16. Precipitation Climatology Animation