(Radio Iowa) – While an active La Nina pattern continues to form over the Pacific Ocean, questions remain about what impact it will have in Iowa. Past La Ninas have led to colder winters here with some increase in snowfall. Meteorologist Dennis Todey, director of the U-S-D-A’s Midwest Climate Hub in Ames, says it appears November will be more mild than cold. “It looks like, after this cold stretch, we may be getting into a bit warmer period again for a decent part of November,” Todey says. “Are we done with La Nina and what it’s going to do for the overall winter? No, I don’t think so. I think we’re still going to see some cold coming in and more of that may be occurring later in the winter.”

Some longer-range climate maps indicate warmer-than-normal temperatures early next year, but Todey says nothing’s certain. “We’re not locked into what we are at this point and if you look at the outlooks, they are still shifting as the winter goes on,” Todey says. “The cold may be coming in and it may be the warmth of the central plains, so let’s keep an eye on this.” While we can study what’s happened during past La Ninas, there’s no guarantee this latest one will follow the playbook. “While there are some averages we can look at in the way of La Ninas, and those have been reflected in the outlooks, there are some of these big events that have not looked quite the same and have taken on a different view,” Todey says.

“That may be what we’re seeing here, at least for the first part. There’s plenty of winter to come. I don’t think the story is written about this La Nina yet this winter.”  A La Nina occurs when sea surface temperatures in the central and eastern Pacific Ocean cool below long-term normal trends.