CHICAGO, ILLINOIS — A potentially major snowstorm is taking shape across the Midwest, but significant differences between forecast models are creating uncertainty in exactly where the heaviest snow will fall — and just how intense this system may become.
Meteorologists are closely watching notable differences in storm amplitude, north-south track shifts, low pressure intensity and forward speed among leading weather models. These discrepancies will determine whether Chicago and surrounding northern Illinois communities sit in the heart of the snow band — or closer to the rain-snow line.
Key Model Differences Emerging
The latest guidance shows the HRRR model depicting a slower, more amplified system tracking farther north compared to other global models.
Specifically:
- The HRRR projects a stronger low pressure center lifting through the central Plains into the Upper Midwest.
- The ECMWF model is also amplified but slightly less aggressive and marginally farther south.
- The AI-based AIFS solution trends weaker and farther south compared to both HRRR and ECMWF.
These differences may appear subtle, but even a 50–100 mile shift in track could dramatically change snowfall totals across Chicago, Milwaukee, Madison and Detroit.
What This Means for Chicago
Under the more amplified and northern solutions, Chicago would remain solidly in the heavy snow shield, with strong deformation banding wrapping across northern Illinois into southern Wisconsin and Michigan…