What do your middle school geography class and your ability to plan for more forage and herd expansion have in common? You might say it begins with a familiarity of the Pacific Ocean.
Don Day, meteorologist and publisher of the DayWeather podcast, told members of the National Cattlemen's Beef Association (NCBA) Agriculture and Food Policy Committee that understanding the three-year drought and most of 2023’s outlook depends on understanding the Pacific and its changing temperatures.
“The Pacific Ocean is the largest of anything on earth. There's no other object bigger than the Pacific Ocean,” Day said. “What I want you to think of the Pacific Ocean is it's like a battery. It's like an engine. And when that engine is warm, when the water temperatures near the equator tend to be a little bit warmer, there's more energy available in the system to create weather.”
Day further compared the El Nino effect – where warmer waters in the Pacific create the energy – to hot water in your bathroom.
“What happens to all the mirrors and the metal in the bath? It fogs up, right? If you've got more water, you've gotten more energy and have more water vapor that goes into the air.
"Conversely, when the Pacific is cold, it's like the battery is on low. It's like the engine is not running as efficiently. So when the Pacific goes through these warm and cold cycles, our weather reacts to it.”
It wasn’t until the late 1980s and ‘90s that climate scientists began to fully understand the cycles. Those same scientists “don't have a good grasp really on why the Pacific goes through these warm and cold cycles. We've got some ideas, but it's very much new.”
By contrast, in the cooling of the Pacific Ocean, known as La Nina, the energy becomes more dormant and may even shift warmer waters toward the western side of the ocean. Australia has benefited from the three-year La Nina pattern to provide drought relief in that country.
As the current three-year La Nina begins to change to warmer waters, Day reiterated how this La Nina has been a very rare case of a longer run.
“When you put together multiple years of La Nina, you are going to have a severe drought.”
Making the impact even tougher is how a series of multiple-year La Nina patterns have hit over a series of periods over a generation.
“In the last 30 years, we've had three multiyear La Ninas. The last time that happened was in the 1950s. So this is something that hasn't occurred in a long time. So if you think we've kind of been picked on in the last three decades with three severe droughts, you're right.”
Studying the issue
More attention needs to be paid to the issue, Day said, rather than when El Nino patterns bring major weather to the West Coast. That tends to make headlines as far as California, but El Nino is typically good news for Western, Midwest and Southern regions of the country with more snow and precipitation.
Speculation also exists that climate change is responsible for the run of increased and longer La Nina patterns. But Day counters that a cooler Pacific like what has occurred more frequently doesn’t reflect warmer climate.
“What causes the Pacific to go through these warm and cold phases, we don't know – can be solar, it can be underwater volcanic activity, but we do know the cycles have been in existence for thousands of years by looking at sequence settings."
Weather climatologists don’t like examining current models by themselves and place context with historical records to create an analog analysis. Very few multiyear droughts occurred in those decades. A few bad drought years were common, but with only a few consecutive.
Since the 2000s, however, the run of La Nina years running together have been intense, with major dry periods from 1999 to 2002, 2010 to 2012 and 2020 to 2023.
Day said climate forecasts had indicated an end to La Nina last spring, but the computer models were “spectacularly wrong” when Pacific temps dropped in July.
This leads to the question if La Nina could again stretch and break more models in 2023.
When analog techniques and computer models show a La Nina ending, confidence goes up, Day says. The issue, however, is when does the turn happen? If a La Nina continues into spring or early summer, you’re not going to catch up in precipitation.
“So we might very well go into what we call the neutral phase, or La Nada, which means ‘nothing.’ But nothing is good, because you’re not in La Nina anymore.
“If we can transition into La Nada by spring and see those sea surface temperatures warm up over the summer, that's good news. That should mean the western United States is going to turn to transition to a wetter weather pattern, and we already have.”
