By Matt Makens Atmospheric Scientist

Behind the seasonal changes , ( i . e . fall , winter , spring , and summer due to the tilt of the Earth ) El Niño and La Niña are the second biggest influence on our weather . Naturally , these two cycles deserve lots of attention .

Earlier this year , we were still in the grip of La Niña , but from April through August , we saw a transition toward El Niño . This change is , in part , responsible for the wet weather we saw from the Texas Panhandle to parts of Montana in late spring and early summer . Plus , it is no surprise to see the drought migrate from the Southwest into the Midwest and Great Lakes region , as that fits the transition to a new pattern . I will discuss drought in a moment , as El Niño events carry their own drought problems for some regions .

As discussed , La Niña faded earlier this year . El Niño began to develop in the spring and , by summer , had a more powerful grip on the atmosphere . There are multiple ways of measuring how

strong the grip is , whether that be in the atmosphere , ocean or a combination of those two .

Most forecasts you will see for El Niño are from one specific area of the Pacific Ocean . Since that is most commonly what you will see , I will use that to give you some perspective on the El Niño of 2023-2024 .

I can show you all El Niño events since 1980 on one graph ( Image 1 ). Each individual line represents the ocean temperature anomaly in that specific region I just mentioned . You can see multiple years surrounding 2023 ’ s line through this summer .

We can see a lot of variation between those lines — and that ’ s the point ; no two El Niño events will be identical . However , we can thin the selection down to those other events that are most like this one we are in now .

Based on previous similar years , that red line representing 2023 will likely peak later this year . Once we cross into 2024 , history shows a trend that will take us back out of an El Niño and into neutral territory . Yet , our current trajectory matches history , toward a moderate to one of the stronger events since 1980 for the winter .

Considering this , what have these most similar years done to the country ’ s temperature and precipitation patterns ? Let us look . Remember , this is just the average of those similar El Niño events and is more of general guidance versus a forecast for this exact event .

Let us start with temperatures ( Image 2 ). Moderate to strong El Niño events will lean toward warmer-than-normal temperatures across the northern states , especially the Pacific Northwest , Northern Rockies and Northern Plains . Cooler-than-average temperatures across the southern states , especially the Southwest and Southern Plains .

Recall the National Cattlemen article from August when I showed you the dramatic difference between the temperature pattern between strong and weak El Niño events , this event is leaning toward the stronger side . That is why the temperature orientation favors those stronger events of the past . Also recalling that article and the precipitation patterns between strong and weak events , let us see how the most similar events have panned out for moisture .

Precipitation from similar El Niños favors the Southern U . S ., Central Plains , and limited pockets of the Pacific Northwest . Again , this map represents the average of similar events .

How might this year be different than these averages shown in adjacent image ? First , the ultimate strength of this event will change the temperature pattern . The Great Lakes to New England and the Southeastern U . S . would likely be the biggest differences in that case . In terms of precipitation , the West and Southwest are impacted by El Niño during the winter , no doubt , but this region is also susceptible to long periods of moisture related to weather circulations we cannot accurately predict more than a few weeks away . Remember the “ Atmospheric River ” events which captured headlines last winter ? A weaker or more robust season is tied to those events in addition to El Niño .

When do we see the impacts , now that we see generally where we are headed throughout the winter ( I ’ m using the word winter loosely here , meaning the cold season of November through April rather than just the technical three-month winter season )?

El Niño events evolve as the season progresses , just like the atmosphere always ebbs and flows . El Niño ’ s impact typically begins first for the Northwest and Southeast , then shifts toward the central states and finally toward the Southwest and Great Lakes by the second half of the season . I created Image 4 to give you a sense of when your region will see the bigger changes .

The good news with this incoming pattern is the continued progress toward recovering from the historic drought the last La Niña gave us from the Southwest to the Southern Plains . El Niño is no stranger to drought , though . History does not suggest much moisture for the Pacific Northwest or in / around the Great Lakes region .

28 NATIONAL CATTLEMEN DIRECTIONS 2023