颱風迷

Pacific approaches La Niña. Positive Indian Ocean dipole develops.

Issued on Wednesday 14 September | Product Code IDCKGEWWOO

Steady cooling of the central Pacific Ocean since early winter has increased the chance of La Niña returning during the last quarter of 2011. Current ENSO indicators are approaching values typically associated with La Niña events.

However, ocean temperatures are yet to reach critical thresholds, while climate model guidance about their future trends is mixed. Some models predict only modest cooling resulting in a borderline-La Niña event, but others predict stronger cooling beyond La Niña thresholds during the southern spring. A minority predict little or no cooling. Taken as a whole, there is an expectation that the trend towards La Niña will continue.

If a La Niña does form, current indicators are that it will be weaker than the strong 2010-11 event. La Niña events raise the odds of above average rainfall across the north and east of the country, but don't guarantee it. The Bureau's National Climate Centre will monitor the situation closely and issue regular updates via this summary.

The latest observations from the Indian Ocean show the development of a positive dipole event, as predicted over the last few months by climate models, including the Bureau's POAMA. Typically peaking in spring, positive dipole modes increase the chance of below average rainfall over southeastern and central Australia.

內容是在說監測到的異常天氣型態,疑似反聖嬰有在年尾發展的跡象,
上圖SOI值也的確是在正常值偏高的情況,需密切注意未來2個月的變化
但內文提到這次反聖嬰一旦發生,強度不會比去年的強,所以引起的異常天氣或可比去年稍稍減緩


反聖嬰:指的是赤道東風比平均值強,整個渥克環流被加強運作,乾者更旱,濕者更澇

yuloucn

EC次表层监测也说明了这一点，一但位于东太海面下的冷水大幅上翻，那么又一轮强烈的拉峰将会来临

Typhoon

反聖嬰現象還在持續發展當中