It appears winter will make a brief return to Iowa this weekend. And it will come not in the form of snow and wind, but freezing rain. A rush of warm air aloft will melt falling precipitation into rain. Problem is ground temperatures will remain below freezing. This freezing rain setup could produce dangerous icing conditions across the state of Iowa.
The graphic shows the probabilities for an ice storm across Iowa. That’s when any area receives a quarter-inch of freezing rain or more. Areas in blue have a 10% probability while areas in green face a 40% probability. Although on the lower side, the risk of smaller amounts of ice are much greater. As a result, much of the area, especially eastern Iowa are now under a Winter Storm Watch. Central Iowa has been placed under a Freezing Rain Advisory. All of these areas should closely monitor the latest forecasts for any changes.
I cannot stress that last point enough. When we are talking about freezing rain and ice accumulations, the meteorological recipe that goes into that is very exact. You need warm air aloft, freezing conditions on the surface, and a fair amount of moisture. At this time it appears all of those ingredients will be in place. But, if temperatures warm just a degree or two one way or the other, the outcome could change drastically. I urge everyone who plans to venture out on Sunday to stay tuned to the latest forecasts, advisories and road reports.
We’ll have an update later this afternoon, hopefully by then the forecast models will get a better idea of what’s to come.