WEATHER UPDATE
A VERY STRONG EL NIÑO IS COMING: WHAT COULD THIS MEAN?
By Matt Makens Atmospheric Scientist
September is a transitional month, not just for producers but for the weather pattern, too. As summer grass winds down and weaning approaches, many of you are reviewing hay supplies and beginning to turn your attention toward winter.
This year, there is a weather factor to consider that we have not had but once in the past six years— El Niño. This event is already stealing headlines for its potential strength by winter. The main takeaway: El Niño raises the odds of wetter conditions across parts of the southern U. S. this fall and winter, but it will not affect every region evenly or on the same timeline. Producers should use it as one factor in winter forage, feed and cattle weather planning rather than as a guarantee of drought relief.
The tropical Pacific Ocean has warmed steadily above average, moving the pattern into El Niño. Data indicate this event could become one of the strongest on the modern record by fall, with ocean and atmosphere conditions already comparable to 1997. Strength matters because stronger El Niño events are more likely to shift North American weather patterns during the colder months. Still, this event will not necessarily behave like 1997, 1982 or 2015. Each El Niño is different, and this one has offsetting factors that could limit the wet signal in some areas.
Timing is the first thing to understand. Through August, the monsoonal ridge and associated“ heat dome” were the main pattern. Although El Niño was developing rapidly, its influence over the U. S. usually strengthens later in fall and winter. September is a transition month, when shorter-term patterns may dominate before the El Niño signal becomes more obvious.
This is especially important across the Southern Plains. Historically, El Niño favors a more active southern storm track and wetter conditions across the southern U. S. during the cooler months. For producers in Texas and Oklahoma, that could eventually bring needed moisture for winter forage. However, the rains may not arrive immediately, so producers with poor pasture conditions should manage grass and feed supplies carefully.
From late fall into winter, the Southern Plains become one of the key areas to watch. El Niño winters have historically favored precipitation across the southern U. S., but some events have produced much more moisture than others. A wetter late fall and winter could improve wheat
establishment, forage production and soil moisture going into spring 2027. However, the 2023-2024 El Niño is a reminder that even strong events do not guarantee rainfall. El Niño changes probabilities, and offsetting factors this year may reduce the wet signal in some areas.
Do not assume El Niño moisture will spread equally across the Plains. Kansas, Nebraska, Wyoming and eastern Colorado sit in a zone where the precipitation relationship becomes less reliable. Farther north, from Montana to the Dakotas, El Niño winters often lean milder and drier. For Northern Plains producers weighing drought risk in winter plans, El Niño is not the drought-breaking signal it can be farther south. Along parts of the Front Range and nearby plains, strong El Niño events have historically increased the chance of significant snowfall.
The point is for producers to recognize the regional differences El Niño events can create. Winter grazing and feed plans for the Southern Plains should not be reapplied without adjustment to the Central Plains, Great Plains or Northern Plains. Texas and South Dakota may see very different results by the time this event winds down next spring.
I have spent a lot of time discussing precipitation, so let us turn to temperatures for a moment. El Niño winters frequently favor milder temperatures across the northern U. S., which could reduce cold stress and feed requirements during parts of the winter. But historical averages can be deceiving. A winter may end up warmer than average and still include short periods of extreme cold. El Niño can reduce the frequency of cold outbreaks, but it does not eliminate them. The message is to be cautious when interpreting“ milder winter”— the timing of one cold event could still have a significant impact on an operation. The same caution applies to“ drier than average.” That does not mean bone dry; it means precipitation may be less frequent or reduced, making timing especially important.
A final thought: mud. Producers who remember past El Niño events may already be thinking about it. That is the tradeoff. El Niño moisture can improve drought conditions, wheat prospects and pasture prospects across parts of the southern U. S., but it can also produce periods of difficult cattle weather.
Look for region-specific forecasts in your upcoming fall Directions magazine. www. NCBA. org NATIONAL CATTLEMEN 25