The weather profile of the atmosphere this evening is set for rain/freezing rain/sleet/snow. It just depends on where you are in eastern Iowa. In parts of central and eastern Iowa (roughly along Highway 20) sleet and freezing rain is falling. The vertical profile of the atmosphere typically looks like this for freezing rain to occur. Similar profile for sleet.
In northern Iowa, there is not much of a warm layer, so light snow (around 1″) is still possible tonight. In parts of central and east central Iowa there is a warm layer aloft and it doesn’t look like it is going to cool off very much while the precipitation is around.
Here is the temperature profile of the atmosphere this evening roughly over the area near Highway 20..
27° 700 mb (cold)
36° 500 mb (warm)
31° Surface (cold)
Areas south of Highway 20 are most likely to be just rain.
Precipitation is still forecast to taper off between 1 and 3 AM, from west to east. Use caution on the roads since some of the roads will be icy. Elevated surfaces have the best chance of icing up later tonight. Temperatures will hold steady near freezing all night.
Posted under Update
This post was written by Schnack on March 24, 2015