El Niño is on the rise right now in the Pacific. Latest readings show us continuing to head toward an official El Niño event. Latest ONI shows us just passing the El Niño threshold of 0.5C above normal SST in the Niño 3.4 region. Despite crossing this threshold, we are not in an official El Niño until we have 3 consecutive months of +0.5C SSTs in this region. So while we are not there yet, we are well on our way as temps continue to warm relative to normal. Below is a graph from the CPC that shows our chances through the rest of the year of El Niño/Neutral/La Niña:
As you can see, El Niño becomes increasingly likely through this summer. By the time late Fall and early Winter come around, our chances are nearly 80% of being in an El Niño event.
The big question is “Will this be a strong event?” It is my belief, based on historical records, that weak El Niños don’t favor northern Utah much. However, strong El Niños do increase our chances of having above average years. Looking at the model forecasts, we can see the following:
The dotted line is the model average, which shows our ONI value increasing to +1.0 or so by Fall. This is a weak to moderate El Niño event. The strong El Niño events of the past (83-84 and 97-98) saw ONI values in excess of +2.0. Right now, according to the models at least, it looks doubtful that our El Nino will be overly strong.
How about summer? Typically El Niño summers are slightly wetter than normal with a strong monsoonal tap which starts earlier in the summer. The latest 3-month outlook from the CPC reflects this with greater than average precipitation forecasted for the 4-corners region.
So for now we’ll just have to wait and see how strong El Niño gets this summer. Again, I’d say the stronger the better for us in Utah as we’ve typically done well in strong El Niño events in the past.