A large storm system is expected to move through the state beginning on Wednesday and lasting through the end of the year (Friday). This is likely to bring a plethora of precipitation to the state during that time. Fog will continue to be a problem tonight and will again be a factor Wednesday as fog and some light drizzle/freezing drizzle moves into the state. Thursday, temperatures will rise above freezing across most of the state switching the freezing drizzle and light freezing rain to all drizzle and rain. It may be longer to switch over in the heavier snowpack areas of NE Iowa, but by the afternoon everyone should be seeing rain of some kind.
Readings are not likely to drop below freezing Thursday night, so precipitation may stay in the liquid form throughout the night. There is a chance that again in the heavier snowpacked areas, the precipitation may switch back over to freezing drizzle or freezing rain. Friday (New Year’s Eve), another low pressure system will move through the state, transporting even more moisture in. This will raise temperatures well into the 40s in the heavier snowpacked areas and lower to middle 50s in the south, where most of the snowpack is expected to be gone by then. A lot of rain is possible along with an isolated thunderstorm which, due to the frozen ground and snowpack, may lead to some urban flooding in some areas where drainage may be blocked by snow.
A very strong cold front will sweep across the state through the day, crossing the western counties in the late morning through Noon, the central counties in the afternoon and the eastern counties in the late afternoon or evening. With the passage of the front, temperatures will immediately crash, with some locations possibly seeing 20-25°+ drops in a few hours. While most of the precipitation is expected to be ahead of the front, we can’t rule out the chance of some sleet, freezing rain and snow on the backside, but travel problems shouldn’t be a problem. The New Year will bring much colder temperatures and a chance of a few flurries or snow showers.
There may be a few slight changes as we draw closer to the event.