After a few model runs over the last couple days, consistency has been the name of the game when it comes to an upcoming winter storm. Although some minor differences remain, the big picture points appear to be in order and we have a relatively good idea of how things will play out.
A relatively disorganized disturbance will move into the Upper Midwest, bringing with it the threat of snowfall from New Mexico, all the way up Iowa and beyond. Things will get going late Friday night when rain and snow showers will reach the area. A rush of warm air should start bring an all rain event for much of Saturday.
But as the low pressure center becomes more organized somewhere over eastern Iowa, we’ll see a stronger rush of cold air. This will begin the changeover to snow in western Iowa sometime during the evening on Saturday. That changeover to snow will continue to spread east during the overnight hours and into Saturday.
One bit of good news for Iowans and travel conditions, the cold air should lag behind the main axis of precipitation as it pushes through the state. This will lead to some significant rainfall but should not cause any major snowfall accumulations.
So now for the big question, how much snow are we looking at? The best guess at this time is a widespread swath of 3”-6” especially in the northwest quadrant of the state. As a result I would anticipate a Winter Storm Watch to be issued before Friday Night. By Saturday we should see a clarification of that watch into either a Winter Weather Advisory, a Winter Storm Warning or some combination of the two.
The eastern half of the state could see a lot of rain, but worst case scenario I would expect 1”-3” of snow in eastern Iowa when all is said and done. More good news is that there are no major storms in the immediate future for Iowa. But we are moving into a much colder and eventually more active winter weather period. For now we’ll continue to monitor any changes in the current forecast and will post any updates when conditions warrant between now and Sunday.