Seasonal update and outlook
Seasonal model forecasts for Victoria
[Source: LCT Update and Outlook - Sept 10 2012]
Current month forecast (1-3 month outlook)
Pacific Ocean: Warm (weak El Niño)/slightly warm
Indian Ocean: slightly cool/average
Rainfall: average/slightly drier Temperature: mixed
Previous month forecast ( 1-3 month outlook)
Pacific Ocean: warm/weak weak El Niño
Indian Ocean: mixed
Rainfall: average/slightly drier
Temperature: average/slightly warmer
Cropping State round up (compiled Sept 04 2012)
Mallee: Decile (1-2)
Early barley at heading but most cereals and canola at early podding. Early sown crops with subsoil moisture still looking good. Late sown four leaf canola and cereals crops going blue and purple in the warmth and lack of moisture. Great variability with up to 50% of crops looking poor.
Wimmera: Decile (1-6)
Cereals range from mid tillering to second node. Canola range from 10% to 50% flowering. Everything looking good but starting to dry at the surface. Some topdressing completed in early August, lack of ideal opportunities. Pulses getting ground cover and looking good. Large variability between early and late sown crops exists.
Northern: Decile (2-5)
NE- Canola in full flower and some early podding. Cereal at 2-3 nodes some at flag leaf emergence. First stripe rust starting to appear on susceptible wheat varieties unprotected by fungicide. Plenty of nitrogen topdressing occurring, crops looking great. NC- Early sown wheat at flag leaf, canola still in full flower. Southern areas looking good. Irrigation being considered and applied where needed.
South West Decile (6-8)
Western areas remain wet, many crops are exhibiting water logging symptoms and ducks are getting bogged. Installed drainage is working well. Central areas looking good, plenty of nitrogen application. Canola early flowering, cereals at first node.
Gippsland: Decile (6)
Crop conditions variable. Early sown cereals at 2nd node varying through to just sown. Canola 30% flowering. Nitrogen and potassium are being applied based on poor tissue tests as wet weather has leached them out. No disease issues, but slugs rampaging
Current climate status and trends Southern
Source: LCT Update and Outlook as of 10 September 2012
Southern Oscillation Index (difference in air pressure between Tahiti & Darwin) The latest 30-day SOI value (10 September) is + 1.2 (neutral). Sustained positive values of the SOI above +8 may indicate a La Niña event, while sustained negative values below −8 may indicate an El Niño event. Values of between about +8 and −8 generally indicate neutral conditions. The SOI has shown erratic behaviour and risen from El Niño back to normal levels in the past few weeks. This indicates the pressure patterns around the Equator are now normal but have been swinging between weakly El Niño and normal.
Sea surface temperatures (SST) have been hovering close to El Niño temperatures. The Eastern Pacific is 0.69oC and the central Pacific (NINO 3.4 region) is now just above El Niño threshold at 0.92oC, (threshold of 0.8oC). In the Indian Ocean, the area of cool anomalies off Java cooled further, looking very IOD+ like with the DMI index at +0.81oC (above the 0.5 oC threshold). The Arafura and Timor Seas have rewarmed to normal temperatures, the Coral Sea remains normal.
Victoria has seen normal cloud in the last 30 days. Extra cloudiness in the western Pacific and Coral Sea persists. Cloud at the International Dateline junction with the Equator is at normal levels, but should be abundant if a fully fledged El Niño was in operation. A lack of North West cloud band activity persists and the lack of cloud off Sumatra shows an IOD+ like signature.
In August, the equatorial trade winds in the western Pacific were slightly reversed, as the atmosphere was attempting to form an El Niño. In the second week of September the trade winds are confused, with the western Pacific strongly reversed like El Niño but with the central Pacific stronger easterly like La Niña. This confusion makes an El Niño harder to happen.