Southern Hemisphere: Weather & Climate over Major Crops Areas

1. Southern Hemisphere: Weather & Climate over Major Crops Areas Update prepared by Climate Prediction Center / NCEP 3 May 2010 For Real-time information: http://www.cpc.noaa.gov/products/JAWF_Monitoring/

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

3. Highlights • Australia: Mostly dry weather continued across Australia’s eastern farmlands, with seasonable temperatures. The GFS forecasts continued dry weather in Queensland and northern New South Wales, with light showers possible in the southeast. • Southern Africa:Showery weather continued across interior farmlands of southern Africa, though dry weather persisted in western South Africa. The GFS forecasts a significant decrease in rainfall across the corn growing regions, while rainfall increases in Western Cape, South Africa. • South America: Dry weather continued across central Brazil, while a cold front brought heavy rain to the southern states. Behind the front, a hard freeze ended the growing season across La Pampa and much of Buenos Aires in Argentina. The GFS forecasts dryness to continue through much of Brazil, with lighter rainfall lingering across Parana and Santa Catarina.

4. ENSO Current Status • General Summary: • El Niño is present across the equatorial Pacific Ocean. • Sea surface temperatures (SST) are more than 0.5ºCabove-average across most of the equatorial Pacific. • Based on current observations and dynamical model forecasts, El Niño is expected to continue through the Northern Hemisphere spring 2010 and transition to ENSO-neutral conditions by Northern Hemisphere summer 2010. During the last 4 weeks (4 Apr – 1 May 2010), equatorial SSTs were more than 1.0°C above average in large areas between 170°E and the west coast of S. America. For more information go to: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/enso.shtml

5. MJO Index -- Recent Evolution Ensemble GFS (GEFS) MJO Forecast • 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 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 MJO Current Status During the previous week, a pronounced MJO signal developed in the tropics, with the convective phase moving into the Indian Ocean. The GFS MJO index forecasts indicate a robust MJO signal propagating eastward through the Indian Ocean during week 1. Ensemble members remain in good agreement through week 2, depicting the convective phase translating eastward through the Maritime Continent. For more information go to: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

6. Southern Hemisphere Monsoons Current Status South America Southern Africa Australia Rainfall Anomalies: Last 90 Days Rainfall Anomalies: Last 90 Days Rainfall Anomalies: Last 90 Days Monsoon Season: NOV-APR Monsoon Season: NOV-APR Monsoon Season: OCT-MAR Long-term precipitation accumulations were near average across southern Africa’s corn growing regions. Below-average rainfall persisted in north-central Mozambique and Kwa-Zulu Natal’s sugarcane regions. Below-average rainfall was observed across much of Brazil as the rainy season came to an early end in April across the Brazilian Plateau region. Above-average rainfall was observed across parts of southern Brazil, NE Argentina, and Uruguay, but below-average rainfall persisted through much of Rio Grande do Sul. Near- to above-average rainfall during the previous three months was observed across the eastern half of Australia, though drier weather has developed more recently in north-central Queensland. Persistently below-average rainfall was observed across much of Western Australia. For more information go to: http://www.cpc.noaa.gov/products/Global_Monsoons/

7. 200-hPa, 925-hPa Wind & Temperature Anomalies- Recent 7 days Southern Hemisphere Circulation A C C 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. • During 25 Apr – 1 May 2010, an area of enhanced anomalous 200-hPa anticyclonic circulation was centered near northeastern Brazil. A weak area of enhanced anomalous 200-hPa cyclonic circulation was centered near Tasmania, Australia. • At the low levels of the atmosphere, above-average temperatures continued across most of Brazil. Below-average temperatures were observed across southeastern Australia.

8. Omega Anomalies and Total Precipitation - Recent 7 days 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. 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. • During 25 Apr – 1 May 2010, strong anomalous sinking motion (positive omega, blue oval top panel) persisted across eastern Brazil. In contrast, strong anomalous rising motion (negative omega) developed across northwestern South America and continued in southern Brazil. Anomalous sinking motion was also observed across western and southeastern Australia.

9. Australia • Rainfall Total & Anomaly Patterns • Temperature Patterns • GFS Forecast

10. Rainfall Total & Anomaly Patterns: Last 7 Days Total Anomaly During the last 7 days, mostly dry weather was observed across the continent. Significant rainfall was limited to the Gulf of Carpentaria region, though accumulations remained below last week’s forecasted amounts.

11. Rainfall Total & Anomaly Patterns: Last 15 Days Total Anomaly During the previous 15 days, below-average rainfall was observed across east-central Australia, including southern Queensland and northern New South Wales.

12. Rainfall Total & Anomaly Patterns: Last 30 Days Total Anomaly DRY During the previous 30 days, above-average rainfall was observed across arid regions in central Australia, but below-average rainfall fell across the primary summer and winter grain croplands of the east.

13. Recent Evolution: RainfallLast 30 Days • 30-day rainfall time series across eastern Australia depict the recently drier conditions as the summer growing season winds down.

14. Temperature (°C)Based on GTS Stations (no QC) Extreme Minimum Extreme Maximum Mean Anomaly • During 25 Apr – 1 May 2010, near- to below-average temperatures were observed in southeastern Australia, with near- to above-normal temperatures elsewhere.

15. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 1-7 Total Anomaly For Days 1-7 (3 – 9 May 2010), the GFS forecasts mostly dry weather to continue across eastern farmlands. Light showers are possible across the southeast.

16. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 8-14 Total Anomaly For Days 8-14 (9 – 15 May 2010), seasonable dry weather or light showers are forecast across most of Australia. Rain continues to be forecast across the Gulf of Carpentaria region, though no tropical cyclone activity is currently forecast.

17. Forecast from 19 Apr 2010 Valid 26 Apr – 2 May 2010 Forecast from 26 Apr 2010 Valid 26 Apr – 2 May 2010 Observed Valid 25 Apr – 1 May 2010 Total Total Total Anomaly Anomaly Anomaly Forecast Verification: Australia

18. Southern Africa • Rainfall Total & Anomaly Patterns • Temperature Patterns • GFS Forecast

19. Rainfall Total & Anomaly Patterns: Last 7 Days Total Anomaly • During the last 7 days, showery weather continued across Botswana and northern South Africa, while mostly dry weather prevailed elsewhere.

20. Rainfall Total & Anomaly Patterns: Last 15 Days Total Anomaly During the last 15 days, above-average rainfall was observed across Botswana and northern South Africa.

21. Rainfall Total & Anomaly Patterns: Last 30 Days Total Anomaly During the last 30 days, most regions received rainfall, with the heaviest amounts falling across extreme northern South Africa and eastern Botswana. Dry weather prevailed across western South Africa.

22. Recent Evolution: RainfallLast 30 Days • 30-day rainfall time series depict the recent showers coming to an end across most of southern Africa. Most eastern regions received above-average rainfall during the previous month, though below-average rainfall persisted across western South Africa (bottom left panel).

23. Temperature (C)Based on GTS Stations (no QC) Extreme Minimum Extreme Maximum Mean Anomaly Temperatures across southern Africa were below-average across Botswana, Zimbabwe, and Mozambique during the previous week, while above-average temperatures were observed across western South Africa.

24. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 1-7 Total Anomaly For Days 1-7 (3 – 9 May 2010), mostly dry weather with isolated light showers are forecast for southern Africa. Increased rainfall is forecast for South Africa’s Western Cape province.

25. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 8-14 Total Anomaly For Days 8-14 (9 – 15 May 2010), light, widely scattered showers are forecast to continue across northeastern South Africa with dry conditions elsewhere. Light rain may linger across Western Cape.

26. Forecast from 19 Apr 2010 Valid 26 Apr – 2 May 2010 Forecast from 26 Apr 2010 Valid 26 Apr – 2 May 2010 Observed 25 Apr – 1 May 2010 Total Total Total Anomaly Anomaly Anomaly Forecast Verification: Southern Africa

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

28. Rainfall Total & Anomaly Patterns:Last 7 Days Total Anomaly • Heavy rainfall continued across portions of southern Brazil, though accumulations decreased in Rio Grande do Sul as the cold front lifted northward. Elsewhere, dry weather continued to prevail across central Brazil, which is becoming increasingly seasonable from east to west as the climatological rainy season typically ends. • Dry weather prevailed across Argentina, with light showers limited to Formosa in the north. Brazil Argentina

29. Rainfall Total & Anomaly Patterns:Last 15 Days Total Anomaly • Dry weather dominated central and southeastern Brazil during the two week period, while a strong cold front brought heavy rainfall to southern Brazil. • In Argentina, light showers fell across the north, though two-week accumulations were below average across the eastern states. La Pampa and much of Buenos Aires experienced the first freeze of the upcoming winter season. Brazil Argentina

30. Rainfall Total & Anomaly Patterns:Last 30 Days Total Anomaly • Generally below-average rainfall was observed across Brazil’s farmlands. Exceptions included Bahia and portions of southern Brazil, though dry weather dominated the south early in the period. • Across Argentina, below-average rainfall was observed across most eastern croplands. Brazil Argentina

31. Recent Evolution: RainfallLast 30 Days • Time series across South America depict the generally drier than average conditions throughout most croplands. The exception remained portions of southern Brazil, where a stalled cold front continued to bring locally heavy rainfall.

32. Temperature (°C) - BrazilBased on GTS Stations (no QC) Extreme Minimum Extreme Maximum Mean Anomaly Above-average temperatures continued across most of central Brazil, with cooler weather in the south behind the cold front.

33. Temperature (°C) - ArgentinaBased on GTS Stations (no QC) Extreme Minimum Extreme Maximum Mean Anomaly Below-average temperatures shifted northward across Argentina, while areas that fell below freezing last week experienced a pronounced warm-up.

34. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 1-7 Total Anomaly • For Days 1-7 (3 – 9 May 2010), lingering rainfall is forecast to continue across southern Brazil, with dry weather prevailing across most other regions.

35. NCEP/GFS Precipitation Forecasts Forecasts from 3 May 2010 – Days 8-14 Total Anomaly • For Days 8-14 (9 – 15 May 2010), little change to the dryness across South America is forecast, and rainfall across southern Brazil is forecast to decrease by week 2.

36. Forecast from 19 Apr 2010 Valid 26 Apr – 2 May 2010 Forecast from 26 Apr 2010 Valid 26 Apr – 2 May 2010 Observed 25 Apr – 1 May 2010 Total Total Total Anomaly Anomaly Anomaly Forecast Verification: South America

37. Major World Crop Areas and Climate Profiles Crop Calendars by Month http://www.usda.gov/oce/weather/pubs/Other/MWCACP http://www.usda.gov/oce/weather/CropCalendars USDA Crop Information