UNDERSTANDING DROUGHT INDICATORS DURING A POSSIBLE HERD REBUILD
By Matt Makens Atmospheric Scientist
As we look for any positive signs of rebuilding the herd, we must consider how drought conditions affect the pace of heifer retention. Currently, drought is spreading rapidly across the Southwest and will expand northward into central regions this spring. The long-term outlook indicates drought prevalence in both historical analysis and computer simulations. We need to understand the mechanisms driving long-term drought to rebuild the herd efficiently.
Although the severity of U. S. droughts since 1895 indicates no discernible trend1( a slight increase toward wetness), there are decades within that period when drought is absolutely more prevalent— the 1930s and 1950s had notable droughts.
Most recently, drought has been no stranger to the beef industry. Since the late 1990s, we have been subject to a lengthy period of frequent La Niña events. Twenty of the last 30 years have had rainfall deficits for much of Texas1. The last time New Mexico had back-to-back wet years was 1992 and 1993, and since then, the state has gone through 2013 and 2022 as the most severe droughts on record since the 1800s1. These areas will continue to rival some of the worst droughts on record until we break this pattern, a pattern that has gained dominance since the late 1990s.
Expand our scope to the entire south-central to southwestern U. S. and northern Mexico. This region is one that correlates most strongly to El Niño and La Niña but one that also correlates strongly to other global oscillations that add to or detract from El Niño and La Niña’ s dominance. Understanding this big picture will have to be a part of anticipating the rebuild.
Generally, El Niño and La Niña are North America’ s second strongest drivers of weather patterns— second only to regular seasonal changes due to Earth’ s tilt. If this were purely the case, each El Niño or La Niña event would be the same. We know this is not the case, as we learned in New Mexico and West Texas, which
remained in drought throughout the’ 23-‘ 24 El Niño( which can be quite a wet pattern for the South). For the northern producers, La Niña events, too, have behaved in less than stereotypically wet ways.
The term“ El Niño” originated hundreds of years ago from Peruvian fishermen who noticed a periodic warming of the Pacific Ocean waters along the western coast of South America. This warming typically occurred around December, close to Christmas, leading the fishermen to name the phenomenon“ El Niño,” meaning“ The Child” in Spanish, a reference to the Christ Child. Over time, El Niño has come to represent a broader weather pattern associated with significant global weather impacts, including altered precipitation patterns and increased storm activity across various regions.
The term“ La Niña,” meaning“ The Girl” in Spanish, was coined as the counterpart to El Niño. While El Niño describes the periodic warming of the Pacific Ocean waters, La Niña refers to the opposite phenomenon— a significant ocean surface cooling. This cooling leads to different global weather patterns, often characterized by increased rainfall in some regions and droughts in others( drought for much of the U. S.). Because it is colder, this ocean area does not create rising motion or storm development above.
In the global images( above) representing El Niño and La Niña, note how different ocean temperatures are surrounding Australia and New Zealand, the Pacific Ocean north of Hawaii, the Gulf of Alaska and across the Atlantic. Just as global weather changes because of the El Niño and La Niña region, the pattern will also be influenced by the sea surface temperatures elsewhere( and snow / ice coverage at the poles). These conditions are tracked as seriously as El Niño and La Niña but typically get fewer mentions. Behind El Niño and La Niña’ s dominating influence on North
America comes impacts from the Pacific and Atlantic Oceans.
16 APRIL 2025 www. NCBA. org