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The South American Monsoon System: Recent Evolution and Current Status. Update prepared by Climate Prediction Center / NCEP 7 January 2013. For more information, visit: http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/American_Monsoons. Outline. Highlights
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The South American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 7 January 2013 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 • During the last 7 days, above-average precipitation was mainly observed over the western Amazon Basin, extreme southern Brazil, southern Paraguay and northeastern Argentina. Below-average rainfall was found over central and southeastern Brazil. • For 7-13 January, above-average precipitation is predicted for central Brail, and below-average precipitation is predicted for southeastern Brazil, the northern Amazon Basin, and northern Argentina. • For 14-20 January, above-average precipitation is predicted over the central Amazon Basin, and portions of Bolivia, southern Brazil and eastern Argentina. Below-average precipitation is predicted over persist over southeastern Brazil and northern South America..
Rainfall Total & Anomaly Patterns:Last 7 Days Total Anomaly During the last 7 days, above-average precipitation was mainly observed over the western Amazon Basin, extreme southern Brazil, southern Paraguay and northeastern Argentina. Below-average rainfall was found over central and southeastern Brazil.
Rainfall Totals & Anomaly Patterns:Last 30 Days Total Anomaly During the last 30 days, below-average precipitation was observed over central and southeastern Brazil. Above-average precipitation was mainly found over portions of the western Amazon Basin, Peru, Colombia, southern Brazil, Uruguay and northeastern Argentina.
BP Recent Evolution: RainfallLast 90 Days BP: Brazilian Plateau • 90-day rainfall totals are clearly below average over the Brazilian Plateau. 90-day rainfall totals are slightly below average over southern Brazil and the southern Amazon Basin.
Tropical Pacific and Atlantic SST Anomalies SSTs are above average in the equatorial western Pacific and below average in the eastern equatorial Pacific. SSTs are near average in the equatorial 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
Atmospheric Circulation Recent 7 days • Upper panels: During the period of 29 Dec 2012-4 Jan 2013, an anomalous upper-tropospheric cyclonic circulation (red C) was observed over northeastern Brazil. • Lower panels: Anomalous sinking motion (positive omega) was observed over northeastern Brazil, while rising motion was found over southern Brazil, Paraguay and the western Amazon Basin, consistent with the precipitation pattern shown in Slide 4. C 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.
925-hPa Wind &Temperature Recent 30 Days Recent 7 Days • During the 7-day period of 29 December 2012 – 4 January 2013, below-average temperatures were observed over Argentina and Paraguay. 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.
NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 7 January 2013– Days 1-7 Total Anomaly Note: Bias correction based on last 30-day forecast error.
NCEP/GFS Model Forecasts Bias-Corrected Precipitation Forecasts from 7 January 2013– Days 8-14 Total Anomaly Note: Bias correction based on last 30-day forecast error.
NCEP/GFS MODEL FORECASTS • For Days 1-7 (7-13 Jan), above-average precipitation is predicted for central Brail, and below-average precipitation is predicted for southeastern Brazil, the northern Amazon Basin, and northern Argentina. • For Days 8-14 (14-20 Jan), above-average precipitation is predicted over the central Amazon Basin, and portions of Bolivia, southern Brazil and eastern Argentina. Below-average precipitation is predicted over persist over southeastern Brazil and northern South America..
Forecast Verification Forecast not available Forecast not available Observed 31 Dec 2012– 6 Jan 2013
ClimatologyRainy Season Dates ONSET DEMISE