The South American Monsoon System Recent Evolution and

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The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate

The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 15 September 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 •

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

Highlights • 30 -day rainfall deficits continue over portions of the Amazon Basin and

Highlights • 30 -day rainfall deficits continue over portions of the Amazon Basin and southern Brazil. • During the last 7 days (8 -14 September 2014), below-average precipitation was observed over Venezuela, extreme northern Brazil and portions of southern and southeastern Brazil, and above-average precipitation was observed over Uruguay. • For 15 -21 September 2014, below-average precipitation is predicted for portions of the northern and central Amazon Basin, Uruguay and extreme southern Brazil. Above-average precipitation is predicted for central and southern Peru and portions of central Bolivia.

Rainfall Total & Anomaly Patterns: Last 7 Days Total Anomaly During the last 7

Rainfall Total & Anomaly Patterns: Last 7 Days Total Anomaly During the last 7 days, below-average precipitation was observed over Venezuela, extreme northern Brazil and portions of southern and southeastern Brazil, and above-average precipitation was observed over Uruguay.

Rainfall Totals & Anomaly Patterns: Last 30 Days Total Anomaly During the last 30

Rainfall Totals & Anomaly Patterns: Last 30 Days Total Anomaly During the last 30 days, below-average precipitation was observed over the Amazon Basin, Venezuela, Guyana, southern Chile, and portions of southwestern and southeastern Brazil. Aboveaverage precipitation was observed over Uruguay and portions of eastern Argentina.

Recent Evolution: Rainfall Last 90 Days BP: Brazilian Plateau BP • 90 -day rainfall

Recent Evolution: Rainfall Last 90 Days BP: Brazilian Plateau BP • 90 -day rainfall deficits are present over the southern Amazon Basin and the western portion of the Brazilian Plateau. • 90 -day rainfall totals are slightly above average over southern Brazil.

Tropical Pacific and Atlantic SST Anomalies SSTs are above average in the equatorial Pacific

Tropical Pacific and Atlantic SST Anomalies SSTs are above average in the equatorial Pacific and below 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 A • Upper panels: During the period of 6

Atmospheric Circulation Recent 7 days A • Upper panels: During the period of 6 -12 September 2014, anomalous anticyclonic circulation (center indicated by red A) dominated subtropical South America. • Lower panels: Anomalous rising motion occurred over southern Brazil Uruguay and northeastern Argentina, and anomalous sinking motion occurred over coastal areas of southeastern Brazil and the adjacent subtropical South Atlantic Ocean. • 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

925 -h. Pa Wind &Temperature Recent 30 Days Recent 7 Days During the 7 -day period 6 -12 September 2014, temperatures were above average over southern Brazil. 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 15 September 2014 – Days 1 -7

NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 15 September 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 15 September 2014 – Days 8 -14

NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 15 September 2014 – Days 8 -14 Total Note: Bias correction based on last 30 -day forecast error. Anomaly

NCEP/GFS MODEL FORECASTS • For Days 1 -7 (8 -14 September 2014), below-average precipitation

NCEP/GFS MODEL FORECASTS • For Days 1 -7 (8 -14 September 2014), below-average precipitation is predicted for portions of the northern and central Amazon Basin, Uruguay and extreme southern Brazil. Above-average precipitation is predicted for central and southern Peru and portions of central Bolivia. • For Days 8 -14 (15 -21 September 2014), below-average precipitation is predicted for portions of northern South America, and most of the Amazon Basin. Above-average precipitation is predicted for the portions of Paraguay and southern Brazil.

Forecast Verification Forecast from 1 September 2014 Valid for 8 -14 September 2014 Forecast

Forecast Verification Forecast from 1 September 2014 Valid for 8 -14 September 2014 Forecast from 8 September 2014 Valid for 8 -14 September 2014 Observed 8 -14 September 2014

Climatology Rainy Season Dates ONSET DEMISE

Climatology Rainy Season Dates ONSET DEMISE

Precipitation Climatology

Precipitation Climatology

Precipitation Climatology Animation

Precipitation Climatology Animation