by Kayla Sargent
They say in Montana, “if you don’t like the weather, just wait an hour, it’ll change.” A shift bigger than the day’s highs, lows, snow flurries, and sunshine is on its way for much of the nation though, according to Dr. Art Douglas, Professor Emeritus, Creighton University.
Sitting in a cooler-than-anticipated conference center in San Antonio, Texas, where the first snow flurry in what locals said was three years surprised everyone, Dr. Douglas welcomed attendees to “the start of a La Nina.”
“And that’s exactly what La Nina does. It starts bringing more cold air down into the midsection of the country,” he said.
A five-year El Nino pattern which has brought wetter than typical weather to much of the nation will be giving way to drier conditions created by La Nina by mid-summer.
This shift is indicated by changing sea surface temperatures (SSTs). Off the coast of California, South America, and Chile “very cold water is a precursor to the rapid development of La Nina,” Dr. Douglas explained. The SSTs in the Central Pacific, near Hawaii, are on the warm side as are those in the Atlantic Ocean – but forecasts predict a steady decline in temperatures, a pattern that hasn’t occurred since around 2012 – 2013.
“So, you know right away that our weather patterns are going to start being quite different than what we’ve had over the last five to six years,” Dr. Douglas told Cattle Convention attendees.
The shift from El Nino to La Nina has the opposite effect on Australia. Constant El Nino patterns caused widespread drought in Australia, which is now facing devastating wildfires. Dr. Douglas said the shift to La Nina should bring some much-needed moisture to the parched continent.
Going into the start of La Nina, U.S. vegetation health is a bit below values from one year ago. California grasslands, Texas, and the Mississippi Valley are just beginning to show signs of stress. While extreme drought is not a concern in the nation now, a long La Nina pattern could change that, according to Dr. Douglas, particularly in Texas.
“La Nina is dry in Texas,” he said. “Our biggest concern going forward is going to be the state of Texas.”
Precipitation patterns over the last 90, 30, and seven days have been typical of a shift to La Nina where the region from Mexico to Arizona were extremely wet three months ago and became dry more recently. At the same time, the Pacific Northwest gradually becomes wetter. The Midwest, according to Dr. Douglas, is holding on to some moisture, but drier patterns are beginning to show.
“We need to watch that developing dryness in the Dakotas into central Canada,” he said. “We’ve seen a lot of moisture in the Northern Plains (in the last 180 days) but again, looking at La Nina, just recently it has started to turn dry up there and I think it’s going to persist that way.”
One concern Dr. Douglas has observed shifting to La Nina is the lack of snow this winter has brought, clear from Nebraska to Alberta, Canada.
“If we are going to have a cold winter, which is typical of La Nina, we ought to have more snow on the ground to facilitate that cold. We need snow to reflect sunlight, sun doesn’t come to the ground and heat it, therefore the atmosphere stays relatively cold,” he explained. “We don’t have that, we have a lot of open ground.”
Last year, the snow pattern was similar with much open ground from Nebraska to Western Canada at the end of January. However, last year a pattern brought much snowfall from February through March – this pattern is not expected to occur again this year, according to Dr. Douglas.
“So even though last year started looking exactly like this year, we’re going to really diverge,” he said.
As far as temperatures for the next month, Dr. Douglas said the major swings from highs to lows will persist. The month of February is expected to be “quite cold” in the Northern Plains and warm in the Southeast. Conditions point to cold persisting through March and into early April. At the same time, moisture is predicted to be plentiful in the Southeast, but the Southwest is going to begin experiencing drier conditions.
“As we look at the forecast for spring, below normal temperatures are expected from Montana into the Northeastern United States, but not as cold as what it was – maybe only one to one and a half degrees below normal,” Dr. Douglas said.
Then things are expected to warm up going into summer. He said the winter wheat areas in the Plains are predicted to be in a “marginal situation and may not have a good crop this year.” The Corn Belt, on the other hand, is looking at average rainfall and normal temperatures, so the corn crop is not of major concern at this point. California could be looking at a “hot, dry summer” and the far northern states are expected to be warm.
“About the only moisture really getting into the United States in the summer is coming out of the Atlantic, aimed toward the East Coast and then getting into the Ohio Valley,” Dr. Douglas said.
With that, Dr. Douglas wished convention attendees luck with the upcoming year and reminded that a shift to La Nina means a reversal of the weather patterns each region became accustomed to over the past five years.BACK