I am just curious to know whether if there were situations where a La Niña Advisory was declared before, but not enough for a sufficient duration to officially be a La Niña? The same could be said for El Niño and an El Niño Advisory declaration as well. If it hasn't happened before, could this be a first?

It's my understanding that the Australian counterpart has not officially called a La Niña even though most of the typical indicators have been met (needs to be -0.8°C in the Niño3.4 SST for at least 3 months to become established).