Weak La Nina Affecting Wheat Potential in Australia

October 4, 2011

The very strong La Nina in 2010 contrasts with a fledgling La Nina presently.  The La Nina is a climate anomaly that has wide  reaching weather effects in the United States and Australia, affecting wheat production in both  nations.   This report brings you up to speed with current wheat conditions influenced by a "weak" La Nina.   

Strong La Nina in 2010

The La Nina last year was very strong, producing exaggerated weather effects in Australia.  To see an enormous difference in La Nina strength, see the time series of sea surface temperatures.   A weak La Nina has emerged  in August-September, compared to strong La Nina conditions a year earlier.  

New South Wales last year produced a record harvest of winter wheat from very heavy rain with a strong La Nina in effect.   New South Wales wheat lifted the national harvest, compensating in large degree, for a poor crop in Western Australia.  The New South Wales made up 33% of national production,   compared to 19% normally.    Rainfall was very heavy in the Southern Hemisphere winter June-August:

Generous rainfall became too much of a good thing at the harvest, causing December flooding.   Wheat quality was reduced from sprouting kernels and disease.    Even so, the Eastern Australia wheat harvest was excellent,  offseting drought damage in Western Australia and boosting the national yield:

La Nina Weak This Year

The current La Nina is weak.   Sea surface temperatures in the Nino 3.4 region have been hovering around -0.6 C - 0.8 C for several weeks and slightly under the La Nina threshold -0.5 C.    With a weaker La Nina Eastern Australia wheat growing conditions were dry in the June-August Southern Hemisphere winter.

There was good rainfall in September boosting wheat development in Eastern Australia.    It seems too late to recover full yield potential.  Warm August temperatures pushed development.   It would be too late in the crop cycle for wheat to recover from drought damage earlier.

Australia wheat production was pegged at 26.2 million metric tons,  based on the official government estimate from ABARE.   The USDA estimate seems more realistic at  25 million metric tons.