Odds are that the La Niña watch will turn into an advisory, which means all the necessary conditions have been observed. But Mike Halpert, deputy director of NOAA's Climate Prediction Center, doesn't think it's likely to develop beyond a weak system. Even if it turns into a moderately strong one, he says, the forecast isn't going to change all that much. If anything, meteorologists would just become more confident in the prediction they've already made. The only significant changes will come if the La Niña system fails to develop entirely, in which case everything is kind of up in the (literal and metaphorical) air.