1. The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 16 February 2015 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. Large long-term rainfall deficits continue over central and southeastern Brazil. During the last 7 days (9-15 February 2015), below-average precipitation was observed over the Amazon Basin, Northeast Brazil and Uruguay. Slightly above- or near-average precipitation was observed over the remainder of South America. For 16-22 February 2015, above-average rainfall is predicted for portions of the southern Amazon Basin, central and southwestern Brazil, Bolivia and northern Paraguay. Below-average precipitation is forecast for Peru, southern Brazil, Uruguay and northeastern Argentina. Highlights

4. Rainfall Total & Anomaly Patterns: Last 7 Days During the last 7 days, below-average precipitation was observed over the Amazon Basin, Northeast Brazil and Uruguay. Slightly above- or near-average precipitation was observed over the remainder of South America. TotalAnomaly

5. Rainfall Totals & Anomaly Patterns: Last 30 Days During the last 30 days, below-average precipitation was observed over most of Brazil. Above- average precipitation was observed over central and southern Colombia, Ecudor, northern Peru, western Bolivia, and portions of northern and central Argentina. TotalAnomaly

6. BP Recent Evolution: Rainfall Last 90 Days BP: Brazilian Plateau 90-day rainfall deficits are present over the southern Amazon Basin (~300 mm) and the Brazilian Plateau (250-350 mm). 90-day rainfall is near average over southern Brazil.

7. Tropical Pacific and Atlantic SST Anomalies 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 SSTs are above average in most of the equatorial Pacific and near average in most of the equatorial Atlantic. (For details concerning El Niño – La Niña, go to the link below.)

8. Atmospheric Circulation Recent 7 days Upper panels: During the period of 7-13Feb. 2015, anomalous anticyclonic flow (stronger- than-average Bolivian High, center indicated by red A) was located over the central Andes mountains. Lower panels: Anomalous sinking motion occurred over Northeast Brazil, consistent with the negative precipitation anomalies in that region (see Slide 4). 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. A

9. 925-hPa Wind &Temperature Recent 30 DaysRecent 7 Days Low-level (~600 m above sea level) 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 7-13 Feb. 2015, above-average temperatures covered portions of southern Brazil and Paraguay. Below-average temperatures were observed over southern portions of Chile and Argentina.

10. NCEP/GFS Model Forecasts Bias-Corrected Precipitation Total Forecasts from 16 February 2015 – Days 1-7 Anomaly Note: Bias correction based on last 30-day forecast error.

11. NCEP/GFS Model Forecasts Bias-Corrected Precipitation Total Forecasts from 16 February 2015 – Days 8-14 Anomaly Note: Bias correction based on last 30-day forecast error.

12. For Days 1-7 (16-22 February 2015), above-average rainfall is predicted for portions of the southern Amazon Basin, central and southwestern Brazil, Bolivia and northern Paraguay. Below-average precipitation is forecast for Peru, southern Brazil, Uruguay and northeastern Argentina. For Days 8-14 (23 February-1 March 2015), above-average precipitation is indicated for most of the Amazon Basin, Colombia, northern Bolivia and portions of northern Argentina. Below-average precipitation is predicted for Brazil between 12S and 28S. NCEP/GFS MODEL FORECASTS

13. Forecast Verification Forecast from 2 February 2015 Valid for 9-15 Feb. 2015 Forecast from 9 February 2015 Valid for 9-15 Feb. 2015 Observed 9-15 Feb. 2015

14. Climatology Rainy Season Dates ONSETDEMISE

15. Precipitation Climatology

16. Precipitation Climatology Animation