The South American Monsoon System Recent Evolution and

The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 3 November 2014 For more information, visit: http: //www. cpc. ncep. noaa. gov/products/Global_Monsoons/American_Monsoons

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

Highlights • Rainfall deficits continue to increase over portions of central and southeastern Brazil. • During the last 7 days (27 October-2 November 2014), below-average precipitation was observed over southern Venezuela, portions of the central Amazon Basin, and portions of southwestern and southern Brazil. Above-average precipitation was observed over southern Northeast Brazil, Paraguay, extreme southern Brazil, Uruguay and eastern Argentina. • For 3 -9 November 2014, below average precipitation is predicted for central and southern Northeast Brazil, and portions of North-Central Argentina. Above-average precipitation is predicted for portions of Peru, Ecuador, Paraguay, and southern and southeastern Brazil.

Rainfall Total & Anomaly Patterns: Last 7 Days Total Anomaly During the last 7 days, below-average precipitation was observed over southern Venezuela, portions of the central Amazon Basin, and portions of southwestern and southern Brazil. Aboveaverage precipitation was observed over southern Northeast Brazil, Paraguay, extreme southern Brazil, Uruguay and eastern Argentina.

Rainfall Totals & Anomaly Patterns: Last 30 Days Total Anomaly During the last 30 days, below-average precipitation was observed over the southern Amazon Basin in Brazil, eastern Venezuela, central and southeastern Brazil, and southern Paraguay. Above-average precipitation was observed over northern Peru, southern Colombia, Uruguay, extreme southern Brazil and central Argentina.

Recent Evolution: Rainfall Last 90 Days BP: Brazilian Plateau BP • 90 -day rainfall deficits are present over the southern Amazon Basin (~200 mm) and the Brazilian Plateau (~120 mm). • 90 -day rainfall is below average (~80 mm) over southern Brazil.

Tropical Pacific and Atlantic SST Anomalies SSTs are above average in the equatorial Pacific and near to slightly above average in the equatorial Atlantic. (For details concerning El Niño – La Niña, go to the link below. ) A weekly Power. Point summarizing the ENSO Cycle: Recent Evolution, Current Status and Predictions is available at: http: //www. cpc. noaa. gov/products/precip/CWlink/MJO/enso. shtml

Atmospheric Circulation Recent 7 days • Upper panels: During the period of 24 -30 Oct. 2014, anomalous anticyclonic circulation (center indicated by red A) was observed over Southeast South America. A • Lower panels: Anomalous rising motion occurred over northern Bolivia, southern Northeast Brazil, and central Argentina. Anomalous sinking motion occurred over the eastern Amazon Basin, northern Chile and northwestern Argentina. • Rising motion (negative omega, yellow/red shading), usually associated with wetter- thannormal conditions. • Sinking motion (positive omega, blue shading), usually associated with drier-than-normal conditions.

925 -h. Pa Wind &Temperature Recent 30 Days Recent 7 Days During the 7 -day period 24 -30 Oct. 2014, temperatures were much above average over southern Brazil, southern Paraguay, Uruguay and northern and central Argentina. 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 -h. Pa are usually similar to surface observations. Note: Areas with surface pressure below 925 -h. Pa are masked out.

NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 3 November 2014 – Days 1 -7 Total Note: Bias correction based on last 30 -day forecast error. Anomaly

NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 3 November 2014 – Days 8 -14 Total Note: Bias correction based on last 30 -day forecast error. Anomaly

NCEP/GFS MODEL FORECASTS • For Days 1 -7 (3 -9 November 2014), below average precipitation is predicted for central and southern Northeast Brazil, and portions of North. Central Argentina. Above-average precipitation is predicted for portions of Peru, Ecuador, Paraguay, and southern and southeastern Brazil. • For Days 8 -14 (10 -16 November 2014), below-average precipitation is predicted for southern Brazil, southern Paraguay, and northeastern Argentina. Above-average precipitation is predicted for a band extending from Bolivia eastward across central and southern Northeast Brazil.

Forecast Verification Forecast from 20 October 2014 Valid for 27 Oct. -2 Nov. 2014 Forecast from 27 October 2014 Valid for 27 Oct. -2 Nov. 2014 Observed 27 Oct. -2 Nov. 2014

Climatology Rainy Season Dates ONSET DEMISE

Precipitation Climatology

Precipitation Climatology Animation