Southern Hemisphere: Weather & Climate over Major Crops Areas Update prepared by Climate Prediction Center / NCEP 6 December 2010 For Real-time information:

Outline Highlights ENSO Current Status MJO Current Status Monsoons Current Status Southern Hemisphere Circulation Rainfall & Temperature Patterns NCEP/GFS Model Forecast Forecast Verification

Australia: Torrential rainfall overspread Queensland and New South Wales following weeks of above-average rainfall, causing widespread flooding. The GFS forecasts continued heavy rainfall across eastern Australia, potentially exacerbating the flooding situation. Southern Africa: Heavy rainfall erased deficits from Zimbabwe through central Mozambique, while more widely scattered showers continued in South Africa. The GFS forecasts heavy rainfall from Zambia through central Mozambique, with drier weather overspreading South Africa. South America: Thunderstorm activity picked up across central and southern Brazil during the previous week. The GFS forecasts heavy rainfall across Brazil’s northeastern interior during the upcoming week. A drier trend is expected across central Argentina. Highlights

ENSO Current Status For more information go to: During the last 4-weeks (7 Nov – 4 Dec 2010), SSTs were at least 1.0°C below average between 165°E and the South American coast, with departures more than 2.0°C below average in some areas east of the International Date Line. General Summary: La Niña is present across the equatorial Pacific. Negative sea surface temperature anomalies persist across much of the Pacific Ocean. La Niña is expected to last into the Northern Hemisphere spring 2011.

MJO Current Status  The axes (RMM1 and RMM2) represent daily values of the principal components from the two leading modes  The triangular areas indicate the location of the enhanced phase of the MJO  Counter-clockwise motion is indicative of eastward propagation. Large dot most recent observation.  Distance from the origin is proportional to MJO strength  Line colors distinguish different months MJO Index -- Recent EvolutionEnsemble GFS (GEFS) MJO Forecast RMM1 and RMM2 values for the most recent 40 days and forecasts from the ensemble Global Forecast System (GEFS) for the next 15 days light gray shading: 90% of forecasts dark gray shading: 50% of forecasts Yellow Lines – 20 Individual Members Green Line – Ensemble Mean For more information go to: The MJO signal strengthened somewhat during the past week. The GEFS forecasts a moderate MJO signal to propagate eastward during the next 2 weeks.

Southern Hemisphere Monsoons Current Status South AmericaSouthern AfricaAustralia With the rainy season started across southern Africa, a sluggish start to the rains spurned small to moderate deficits across much of South Africa and northern Mozambique. For more information go to: Rainfall Anomalies: Last 90 Days Below average precipitation was observed across South America, particularly in southern Brazil and northeastern Argentina. Three-month precipitation across northeastern Brazil and central Argentina remained near average. Near- to above-average rainfall was observed across most of Australia during the previous 90 days. A small area of below-average rainfall was observed in Western Australia’s primary wheat growing region. Monsoon Season: NOV-APR Monsoon Season: OCT-MAR Monsoon Season: NOV-APR Rainfall Anomalies: Last 90 Days

Southern Hemisphere Circulation 200-hPa, 925-hPa Wind & Temperature Anomalies - Recent 7 days During 28 Nov – 4 Dec 2010, enhanced westerly flow continued across northern Argentina. A strong upper level low was observed over central Australia. Low-level (925 hPa or ~600 m) wind and temperature anomalies are 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. C A A

Southern Hemisphere Circulation Rising motion (negative omega, yellow/red shading), usually associated with wetter-than- average conditions. Sinking motion (positive omega, blue shading), usually associated with drier-than-average conditions. Omega Anomalies and Total Precipitation - Recent 7 days During 22 – 28 Nov, an area of strong anomalous rising motion (negative omega) was observed across eastern Australia for a second week, and was associated with widespread, persistent, and heavy rainfall. CPC daily gridded precipitation analysis over land only. The daily gauge analysis is created on a 0.5 degree lat/lon over the global land by interpolating gauge observations from ~30,000 stations.

Australia Rainfall Total & Anomaly Patterns Temperature Patterns GFS Forecast

Rainfall Total & Anomaly Patterns: Last 7 Days TotalAnomaly During the last 7 days, torrential rainfall continued across eastern Australia, causing widespread flooding of streams and rivers, particularly in inland locations, which inundated farmland, pastureland, and towns.

River Flooding and Persistent Rainfall Persistent rainfall during the past two weeks caused many rivers to flood across Queensland and New South Wales (left). Last week’s heavy rainfall comes following Australia’s wettest spring on record, with many locations across NT, NSW, and QLD reporting record Sep – Nov accumulations. Note that portions of southwestern Australia recorded their driest spring on record. Source: Australian Bureau of Meteorology

Source: Flooded farmland, ranchland, towns, and roads in New South Wales, AU (December 5, 2010) Flooding in New South Wales

Rainfall Total & Anomaly Patterns: Last 15 Days TotalAnomaly During the previous 15 days, much above average rainfall fell across the eastern third of Australia, with the heaviest amounts observed across east central Queensland and parts of New South Wales.

Rainfall Total & Anomaly Patterns: Last 30 Days TotalAnomaly During the previous 30 days, near to above average rainfall was observed across central and eastern Australia.

Recent Evolution: Rainfall Last 30 Days 30-day rainfall time series across the Australian wheat belt depict the widespread rainfall across southern and eastern Australia, while below-average rainfall fell across Western Australia’s croplands.

Temperature (°C) Based on GTS Stations (no QC) Extreme Minimum Anomaly Extreme MaximumMean Below average temperatures persisted across central Australia under a strong upper level low.

NCEP/GFS Precipitation Forecasts TotalAnomaly For Days 1-7 (6 – 12 Dec 2010), continued torrential rainfall is possible across eastern Australia, exacerbating the flooding of rivers and fields. Forecasts from 6 Dec 2010 – Days 1-7

NCEP/GFS Precipitation Forecasts TotalAnomaly Forecasts from 6 Dec 2010 – Days 8-14 For Days 8-14 (13 – 19 Dec 2010), unsettled weather is forecast to persist across eastern Australia, with intensified monsoon rains developing across the northern coastline.

Southern Africa Rainfall Total & Anomaly Patterns Temperature Patterns GFS Forecast

Rainfall Total & Anomaly Patterns: Last 7 Days TotalAnomaly Heavy rainfall overspread Zimbabwe and central Mozambique, while lighter, more scattered showers continued across South Africa.

Rainfall Total & Anomaly Patterns: Last 15 Days TotalAnomaly During the last 15 days, above-average rainfall fell from Botswana eastward to central Mozambique, while parts of South Africa’s corn belt experienced rainfall deficits.

Rainfall Total & Anomaly Patterns: Last 30 Days TotalAnomaly During the last 30 days, precipitation deficits were observed across northern portions of South Africa’s maize triangle, while recent rains brought surpluses to Zimbabwe and northern and central Mozambique.

Recent Evolution: Rainfall Last 30 Days 30-day rainfall time series depict the near average rainfall across South Africa’s corn belt, with above average rainfall further north in Botswana, Zimbabwe, and central Mozambique.

Temperature (C) Based on GTS Stations (no QC) Extreme Minimum Anomaly Extreme MaximumMean Near to above average temperatures were observed across South Africa’s maize triangle during the previous week.

NCEP/GFS Precipitation Forecasts TotalAnomaly Forecasts from 6 Dec 2010 – Days 1-7 For Days 1-7 (6 – 12 Dec 2010) very heavy rain is forecast to fall across Zambia and central Mozambique, areas that already received above average rainfall last week. Drier weather is expected across South Africa’s corn belt.

NCEP/GFS Precipitation Forecasts TotalAnomaly Forecasts from 6 Dec 2010 – Days 8-14 For Days 8-14 (13 – 19 Dec 2010) near average rainfall is forecast across southern Africa.

Brazil & Argentina Rainfall Total & Anomaly Patterns Temperature Patterns First Freeze in southern Argentina GFS Forecast

Rainfall Total & Anomaly Patterns: Last 7 Days Total Argentina Brazil Anomaly Widespread thunderstorms increased moisture across Mato Grosso, but below average rainfall was observed across the eastern third of Australia. Showers and thunderstorms fell across southern Brazil as well. Areas of thunderstorms were observed across central and far northern Argentina, while drier weather continued along the border with Uruguay.

Rainfall Total & Anomaly Patterns: Last 15 Days Total Argentina Brazil Anomaly Above average rainfall in Mato Grosso contrasted with below average rains in Goias, Tocantins, and Bahia. Thunderstorm activity picked up across southern Brazil during the previous week, following persistently drier than average weather. Rainfall overspread much of central Argentina, but deficits remained across eastern and northern farmlands.

Rainfall Total & Anomaly Patterns: Last 30 Days Total Argentina Brazil Anomaly Near to below average rainfall was observed across Brazil’s primary summer croplands, with pockets of above average rains observed in Minas Gerais and Mato Grosso. Generally below average rainfall was observed across Argentina’s northern and eastern farmlands.

Recent Evolution: Rainfall Last 30 Days Below average 30 day accumulations in northern Argentina and southern Brazil contrasted with near to above average rainfall in central and southeastern Brazil. Rains picked up last week across southern Brazil.

Temperature (°C) - Brazil Based on GTS Stations (no QC) Extreme Minimum Anomaly Extreme MaximumMean Above average temperatures were observed throughout most of Brazil.

Extreme Minimum Anomaly Extreme MaximumMean Temperature (°C) - Argentina Based on GTS Stations (no QC) Near to above average temperatures were observed throughout northern Argentina, with chilly weather overspreading southern Buenos Aires.

NCEP/GFS Precipitation Forecasts TotalAnomaly Forecasts from 6 Dec 2010 – Days 1-7 For Days 1-7 (6 – 12 Dec 2010), an area of heavy rainfall is forecast to develop across Brazil’s northeastern interior. Near average rainfall is expected elsewhere, with pockets of below average rainfall in central Argentina.

NCEP/GFS Precipitation Forecasts TotalAnomaly Forecasts from 6 Dec 2010 – Days 8-14 For Days 8-14 (13 – 19 Dec 2010) heavy rainfall is forecast to shift southward into central and southeastern Brazil during week 2. Below average rainfall is forecast across Argentina.

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