Iowa’s unseasonable temperatures forecast to continue

If it seems we're experiencing a more normal winter in Eastern Iowa compared with those of recent years, it really may be too early to know for sure.

Below normal temperatures are expected to continue in Cedar Rapids and Eastern Iowa well into next week. The National Weather Service in the Quad Cities is forecasting high temperatures sharply below normal for this time of year.

'Our high temperatures right now are supposed to be in the high 20s across Eastern Iowa,” NWS meteorologist intern Peter Speck said Thursday. 'Our low temperatures should be in the teens.

'The average high for Cedar Rapids on Jan. 1 is 28 degrees. We are expecting a high of 3 degrees on Monday, or 25 degrees below normal.

'We are expecting a low temperatures of minus 5 degrees on Saturday morning, minus 10 degrees on Sunday morning and minus 15 degrees on Monday morning, It's the reverse of what we had in early December when the high temperatures were 25 degrees above normal.”

But below-normal temperatures and snowfall this time of year do not necessarily portend a severe winter, according to State Climatologist Harry Hillaker.

'Periods like this that are quite cold get your attention, but other parts of the winter may end up being unusually mild,” Hillaker said. 'It's hard to know until we are able to look back and see how things transpire.

'Last winter, we had very little snow over the southern half of Iowa. Some places like Shenandoah only received four inches of snow for the whole winter.

'Northern Iowa, especially north-central Iowa, had above-normal snowfall last winter. Northwest Iowa had record snowfall the previous year.

'The tremendous variability of snowfall in a state the size of Iowa makes it hard to generalize sometimes for the whole state.”

The number of below-zero days annually has declined since the early 1980s, Hillaker said.

'Eleven years out of the last 35-year period averaged less than 10 days of subzero temperatures,” he said. 'There has been quite a number of winters that had very few subzero days.”

Hillaker said the midwinter months of December, January and February have recorded higher snowfall amounts over the past 20 to 30 years, and the 'fringe” months of October, November, March, April and May have recorded lower snowfall totals.

'I think most people's perception is that we don't have as much snow as we used to see or the season is not lasting as long,” Hillaker said. 'My theory is that we tend to remember the really snowy winters.

'Those are the ones we recall because they were unusual. ‘When I was a kid, we had snow up to the window sills.' As time goes on, we think of that as being normal. In reality, that was very much the exception.”

As for how the below-normal temperatures and snowfall may impact the 2018 corn and soybean crops, Mike Duffy, economics professor emeritus at Iowa State University, said it is too early to predict.

'We've really gone down in subsoil moisture with less than a quarter-inch of rain from the middle of October clear into mid-December,” Duffy said. 'Even with normal snowfall, it's pretty hard to say what it will mean in the springtime.

'We need to have rain or snow melt without frozen soil. If we get a lot of snow and a quick warm up, the water will run off instead of going into the ground.”

Speck of the National Weather Service said the frost depth was measured at an inch on Tuesday.

'On Wednesday, the frost depth was six inches,” he said. 'Today (Thursday), it was eight inches.”