The following content was provided by meteorologist Gail Martell of MartellCropProjections.com:
El Nino Weakening Caused Sharp Changes in Weather Worldwide
Strong changes in the weather pattern have developed in the recent 10-14 days and opposite of before. This may be due to a weakening El Nino. Sea surface temperatures in the tropical Pacific Ocean temperatures have generally cooled, moving toward neutral values. The Nino 3.4 region temperatures fell to +0.3 C in late September and below the threshold for El Nino which is +0.5 C.
The cooling sea temperatures in the equatorial Pacific Ocean are symptomatic of a sharp changes in the Pacific Basin winds and air pressure patterns.
Sharply weakening of the El Nino signal has brought about sharp changes in weather conditions that look more like La Nina, and opposite of the preexisting conditions.
The Climate Prediction Center September 24 claimed ENSO-neutral conditions were present, but that El Nino was still expected to develop. Australia scientists claimed that the odds of El Nino happening have eased, but the "risk remains". The most recent report said that despite the shift towards neutral conditions, the tropical Pacific remains warmer than average, Aussie scientists claimed (i.e., much like El Nino).
Late September Weather Reversals
The sharp weakening of the El Nino signal has produced sharp changes in weather conditions. In some areas the change has been positive for crops, in others, negative.
Eastern Australia received generous rainfall in New South Wales that would boost wheat conditions. Rainfall from .50 to 1.5 inches occurred in the northern and central wheat growing areas of the state. Drought had worsened from August to mid September. The top wheat state Western Australia also received generous rainfall reversing a dry pattern.
West Sumatra and Malaysia, the leading palm oil producing areas in Indonesia, were drenched with heavy, soaking rains the past 10-14 days. August conditions had been hot and dry.
Argentina weather turned drier and colder in late September, more in line with La Nina than El Nino. South Brazil weather has been mostly dry, again a symptom of weak La Nina signal.
Though we cannot prove it, the weakening El Nino signal may also be responsible for heavy soaking rains recently in southeastern Europe, Ukraine and southern Russia. These key winter-grain areas previously had been desperately dry and unseasonably hot. Soaking rains recently brighten the outlook for winter wheat and rapeseed planting.
The United States weather pattern has been mixed. A sharply colder weather forecast in 4-7 day outlook is symptomatic of a La Nina signal. However, heavy soaking rains last week in the Southern Great Plains came from a strong subtropical jet stream that is consistent with El Nino.