The reappearance of the La Nina pattern may lead to unsettled winter weather in Nebraska and across the region.
Al Dutcher, extension ag climatologist for the University of Nebraska-Lincoln, says previous La Ninas have led to drier-than-normal conditions.
“La Ninas generally would bring drier conditions but it only takes one or two storm systems to move through to dump that six- to 12-inch snowfall and, all of the sudden, we’ve got half a season worth of precipitation in a single event,” Dutcher says. “I’m a little bit leery in those type of patterns to say that we’re going to be drier than normal.”
Dutcher says while it could be a dry winter ahead, it could also be snowy.
“It’s not uncommon for us, when we are drier than normal, to have above-normal snowfall,” Dutcher says. “That sounds counterintuitive, but the colder the temperatures are, the less moisture there is in the snow. Typical of La Nina patterns, we tend to see quite a few Arctic intrusions into our region which brings those light, fluffy snows with not much in the way of water with them.”
A La Nina occurs when Pacific Ocean surface temperatures cool. Dutcher says he is watching the current West Coast storm track, which could have an impact on Nebraska’s weather.
“These storms coming into the western United States have been a little bit farther south than we typically see during a typical La Nina pattern,” Dutcher says, “and that may bring the overall jet stream farther to the south. If that’s the case, the below-normal temperatures that are predicted for the Dakotas may start to invade Nebraska and could probably pull southward into northern Kansas.”
Dutcher says the next worry would be if the La Nina enhances drought conditions spreading north into the central part of the country next spring.
By Jerry Oster, WNAX, Yankton