Weather conditions this winter are still up in the air, according to an outlook the National Weather Service issued Thursday.
The agency said that in contrast to the last six winters, El Niño and La Niña conditions are not expected to influence this winter’s weather.
While temperatures in much of the South and West are expected to be above normal, the forecast for Missouri and much of the rest of the country is uncertain. According to the National Oceanic and Atmospheric Administration this winter will bring equal chances of above-, below- or near-normal temperatures.
MU climatologist Pat Guinan said a general definition for an El Niño is warmer than normal sea surface temperatures in the equatorial Pacific. He said the effect of El Niño on the United States varies, but it typically results in warmer than normal temperatures in the northern states and above-normal precipitation in the South.
Ed O’Lenic, meteorologist chief of operations for NOAA’s Climate Prediction Center, said many tools are used to make predictions. Each tool can be viewed as a voting member of a democratic group trying to predict winter weather conditions, he said, and this year some of those tools forecast one thing and others another.
“What we like to see is a consensus (of the forecasting tools),” O’Lenic said. “When you have that dichotomy, you get uncertainty.”
In cases when there are no strong indicators, the forecaster must use climatology, Guinan said. In central Missouri the winter is a dry and cool season with about five to six inches of precipitation during the three-month period, he said.
Anthony Lupo, assistant professor of atmospheric sciences at MU, said the government outlook sounds like a copy of his own winter forecast.
Last year, El Niño led forecasters to predict a milder winter in Missouri than what actually occurred, Lupo said. His research indicates there may be two different modes of El Niño, which affect the weather differently.
“There’s a neutral condition this year, so it’s hard to say what will happen,” he said. “And almost anything could.”