The identity of the La Nina event features colder than normal Sea Surface Temperatures (SST) in the eastern and central Equatorial Pacific, these anomalies will be reflected in cooler sub-surface temperatures and the pressure patterns are normal, meaning that the oscillation feature is absent.
Weather patterns around the southern hemisphere will react accordingly. The tele-connexion ability of global climate-cum-weather is axiomatic: one cannot have two-left legs, so as to speak.

Yet the computer models and their analysts are still hesitant about the anticipation of a La Nina event.
This hesitancy is prompted by the computer models failure to indicate the rapid collapse of the late 2006 ENSO and the very rapid switch to almost La Nina conditions across some 2 months: a mere 8 weeks. The functioning weather watchers and their various model inputs are finding some problems, disagreement between various model inputs, which are causing concern among these authorities who, so rightly, expect to set a standard and maintain it. The cause for the apparent misdirection signs given can well be due influences set up by aspects of global warming and its disruption of regular patterns as previously identified. This concern is all to their credit in aiming for as correct and outlook supported by worthwhile comments.
The current doubts can be emphasized by the current fact of the westward limit to the stretch of the colder SST water to support this doubt. These surface waters are driven by stronger surface winds, a La Nina benchmark, but these winds, the far north and the far west of the South East Trade Wind flow pattern, have not, apparently, the drive or ability to go the full, expected distance to be expected from a developed La Nina event.
Yet the global weather patterns look at the La Nina-hopeful situation more positively. At a distance, the downpours and resultant floods of the Indian Monsoon have a La Nina positive aspect.