‘Wild card’ winter in forecast
Drought-watchers looking for some sign of what kind of hand western Colorado will be dealt during the winter snow season won’t get much help from forecasters.
“I’m calling this a wild card year,” said Joe Ramey, a meteorologist for the National Weather Service in Grand Junction.
Earlier this year, weather experts saw signs of a weak El Niño climate pattern establishing itself, which typically means good snow for southwestern Colorado. As late as Oct. 3, AccuWeather.com issued a winter snowfall outlook with a promising above-average snowfall symbol covering Utah, western Colorado and the Four Corners region. But on Nov. 16, it revised its forecast, calling for below-average snow in most of Colorado and predicting the Southwest would be drier than it originally expected.
That’s because forecasters no longer saw an El Niño winter shaping up. Rather, they expect a neutral phase of what’s called the El Niño-Southern Oscillation.
Ramey said waters had been warming in the equatorial eastern Pacific Ocean, which is the sign that an El Niño weather pattern is on its way. But as the year went on, those water temperatures never got warm enough to qualify as an El Niño event, he said.
“The first week of October we all scrambled and recalibrated for ‘No Niño,’ ” he said.
By that, he means that neither El Niño nor La Niña climate conditions are in place.
La Niñas are consistent with colder-than-normal water in the equatorial eastern Pacific. They tend to bring more Colorado snow north of Interstate 70, but also typically produce much less moisture in their second year than in their first, Ramey said. Last winter’s drought came during the second year of a La Niña.
So what do No Niño winters tend to bring western Colorado, snow-wise?
That’s a tough question to answer because such years generally are associated with no preferred storm track, Ramey said.
“We have no skill for (determining) where the jet stream will set up for the winter, and that’s where the storm track will be,” he said.
The bad news is that past experience has shown such years can be either extremely dry or extremely wet in Colorado, “and most often we’re extremely dry,” Ramey said. The reason is that the storm track has a big geographic area in which to establish itself, reducing the chances that it will favor Colorado.
In the last 15 years there have been four No Niño years. One — the winter of 1996-97 — produced above-normal snowfall in the region. The other three — 2001-02, 2003-04 and 2008-09 — were drier than average. The 2001-02 winter was particularly dry, setting the stage for major wildfires the following summer.
Notably, all four previous No Niños resulted in stormy Decembers and Aprils in Colorado.
“So we’re counting on December to start producing some precipitation for us,” Ramey said.
While Ramey’s analysis based on past No Niños isn’t encouraging overall, he emphasized the difficulty of trying to make any kind of predictions about a No Niño year. And even at best, climate outlooks are able to explain about 25 percent of the weather we get.
“So there’s 75 percent that’s just occurring really through random weather through the cold season,” he said.