Hey folks, I hope you had a great finish to 2024 and an even better start to 2025. It is time to check on our old friend La Niña and see what she is up to… You can see from the graphic below that there is a solid swath of colder than average sea surface temperature anomalies along the equator to the west of South America.

We can also measure the strength graphically. The graph below shows the stead increase in the intensity of this event from mid November.

This event has been an interesting one, as we messed around with negative sea surface temperature anomalies that maxed out at -1.1 degrees C in October. We then saw the event weaken to neutral territory in mid November. But since then, we’ve had strong and persistent trade winds along the equatorial Pacific, and that has resulted in the current strengthening trend. The main question is, “Is La Niña peaking right now?” Yes… But, while we are likely seeing this La Niña peaking right now, that doesn’t necessarily mean it will go away rapidly. The graphic below shows various computer model forecasts that are forecasting whether we stay in La Niña, go to neutral, or make a move toward El Niño.

You can see that most of the models hover around neutral as we move into spring and through the summer. Now, the interesting thing about all of those lines is that very few of them actually make it back above the “zero line”. Does that mean we could revert back to La Niña at some point later in 2025? That’s hard to say, but I won’t necessarily discount that threat. However, it is just something I will continue to monitor closely as we move through the year. The reason I won’t discount the threat is due to the Pacific Decadal Oscillation (PDO) still being quite negative/cold. The graphic below shows the PDO values for the past 12 months.

As long as the PDO is strongly negative/cold, the Pacific Ocean traditionally favors more frequent and longer lasting La Niña episodes. This is not “breaking news” as I have talked about this at length since I have been writing this column. For me to relax and be more comfortable about not having drought thoughts on my mind, I would certainly like to see the PDO moderate. Remember, we’ve been in a negative/cold PDO cycle since 1998. If history has anything to say about it, that means that we should be coming to the end of this one. However, with the evidence I have before me, I doubt that will happen in 2025. Does that mean everyone will be battling drought for all of 2025? No, not at all… However, it does tip the scale toward periods of dryness and that is something we all should prepare for… 

Next month I will have updated long range / seasonal model information, which is always interesting to analyze for you. 

Brian