A strong storm will move through eastern Iowa and bring snow and brutally cold air behind it. Snow could be heavy at times and the heaviest snow will be overnight Sunday into early Monday morning.
There is good consistency on the track of this storm, the difference with some of the models is the intensity. That is leading to a difference in moisture and the amount of snow that will fall.
Here's the 0z Euro:
The Euro has come down a little southwest and has slightly higher moisture levels. That's a trend we've been seeing Sunday afternoon.
Here's the latest HRRR, which I also think is under-doing the snowfall totals:
The NAM, hi-res NAM, and GFS have been showing a trend of a wetter system and further southwest with the heavy snow.
Here's the hi-resolution GFS, which has been the most bullish in recent runs:
There may be a brief wintry mix, especially near and south of I-80, in the morning. This will make for slick travel across eastern Iowa and into Illinois.
Then the winds will pick up and blowing snow will become an issue through the day. Bitter cold air will rush in through the day. Temperatures will drop below zero Monday evening and stay below zero until Friday afternoon. Daily records will drop like flies and even all time record records will be challenged this week.
Temperatures will be coldest Wednesday and Thursday mornings. With fresh snow on the ground and arctic air filing in, temperatures will tank.
Here's Wednesday morning's lows and the locations within a degree of record low temperatures circled:
Temperatures will be in the 20s and 30s below zero. Then add some wind and wind chills will be brutal.. dangerous. Wind Chill Warnings will be issued as frostbite can occur within just minutes with wind chills this low:
Wind chills in the 50s and 60s below zero... no one will want to be out in this! Then we repeat on Thursday morning. Here's the low temperatures:
And the wind chills -
These two nights could be challenging all time record low temperatures.. Here are the records:
Burlington........ -27 on 2/13/1905
Cedar Rapids...... -29 on 1/15/2009
Dubuque........... -32 on 1/07/1887
Moline............ -29 on 2/03/1996
Afternoon temperatures will also be below zero and could break records for coldest high temperatures. Many spots will likely break record Wednesday afternoon:
This is going to be a historic stretch of record-breaking dangerous cold. The stretch of cold temperatures will be the coldest since 1996. The wind chills will incredibly low and dangerous to be in for longer than a matter of minutes.