Iowans are enjoying much warmer-than-normal weather for mid-November this week, with high temperatures daily in the 60s and 70s, but forecasters say the end is near.
Climatologist Dennis Todey, director of the U.S.D.A.’s Midwest Climate Hub in Ames, says highs will only be in the 40s by the weekend with lows dropping into the 20s.
“We are finally starting to see that fall transition that we would expect to have where we start seeing more cold air coming through the region and the jet stream will get more active,” Todey says. “It does look like several more storm systems will be coming through the middle part of the country.” Todey says his team is watching the weather developments upstream, across Canada, into Alaska and clear over into Russia.
“There has been activity recently in Siberia with a chunk of cold air,” Todey says. “That’s a ways away but it’s something you start watching to say, ‘Is there enough cold over there that could move up on the pole and eventually start to slide down?’ That’s not going to get here tomorrow but it’s worth watching further out.” Temperatures in Siberia have been running some 50 degrees below normal with heavy snow in the past few weeks. Todey says Iowans likely won’t be seeing any snow fly soon and in some areas, a hard killing frost may still be a few weeks away.
“Any trees or perennials that were still actively growing, could there be enough of a cold snap that would damage them?” Todey says, “Right now, we don’t see that sharp cold that we’ve seen a few times over the last century, where we’ve had these really warm falls and then a short cold snap. We really are not seeing that coming up right now.”
Todey says it appears more likely that a La Nina pattern will take form this winter, which could mean below-normal temperatures and above-normal snowfall.
By Jerry Oster, WNAX, Yankton