A Winter Storm Warning goes into effect at 6 AM Monday for the southern half of Iowa, along and south of I-80. This is where the heaviest snow will fall on Monday.
A Winter Weather Advisory is in effect starting at 6 AM Monday for a few counties just north of I-80 (included Carroll, Greene, Boone, Hamilton, and Hardin county), as they are on the northern edge of the heaviest snow.
As a strong area of low pressure pulls out the the southwest and tracks across Missouri and over Saint Louis, heavy snow will spin north out of Missouri and cover much of the southern half of Iowa. This is the classic storm track for major snow over the southern half of Central Iowa and southeast Iowa.
For those along and south of Hwy 92, Strong confidence in 9-12″ snowfall totals continues to grow. Those along I-80 still look to get a decent amount of snowfall with totals between 6-9″. There is certainly still a chance for higher amounts along the I-80 corridor as there is still some uncertainty in the exact track of this system.
The most uncertainty lies between Hwy 30 and Hwy 20. A sharp snowfall gradient will set up between these two highways. Recent model runs have shown a better chance for this line to set up just north of Hwy 30 with little snow along Hwy 20 and nearly 6″ of snow for most of those who reside along Hwy 30. That means those in between could see totals anywhere between 0 and 6″.
Scattered snow showers will remain possible into Tuesday and Wednesday with cold temperatures in the 20s for daytime highs. We will see more clearing and sun for the end of the week and temperatures will start to warm up as well, reaching the 40s next weekend.