29. Models are still not in perfect agreement, but chances look good for some snow across the north.
The first map (to the right) is from the HPC and shows the quantitative precipitation forecast (QPF) for Day 3, from 7:00 Monday until 7:00 Tuesday. Most of Wisconsin lies within the 0.25 inch contour, so the models are forecasting between 1/4 and 1/2 inch of liquid. Depending on the exact location of the rain/snow line, this could fall as all rain or as snow between 2 and 7 inches. At the moment it looks like anything over 4 inches is a stretch.
The parade of models.
All three model screenshots that I have included in this post are valid at 1:00 Tuesday - all showing the same day & time, of the 12z 3/15 model runs from the ARL's site.
The NAM (first to the left) shows a 1002 mb low over Iowa with a large open hook of precipitation ahead of it. The dry slot is evident over most of western Wisconsin, with the stronger precipitation staying over far southern Wisconsin.
The MM5 (second to the left) shows a 1004 mb low eastern Kansas, with an even wider hook of precipitation ahead of it. It looks like a broader system than the NAM by being spread out over a larger area.
However, by 12z on Tuesday (7:00 CDT) the model takes the low to eastern Iowa at 1001 mb. This would indicate that the MM5 is showing the system moving a little slower than the NAM by 6 hours.
The GFS (third on the left) shows a more disorganized system than either the NAM or the MM5. Though the system is showing up on the model in roughly the same location as the other models, there is no central area of low pressure depicted in the north, only a broad low in Texas. Also, there is no shield of precipitation hooking back around on the north side, only an isolated area of precipitation around eastern South Dakota. By 72 hours (7:00 on Tuesday) this area of precipitation is depicted across northern Wisconsin.
We will have to continue watching the models until there is better agreement.
In each model the rain/snow line is draped across north/northwestern Wisconsin. At this time, it looks like snow up here.
This map from the HPC (to the right) shows probabilities of 4 or more inches of snow on day Day 3, 19:00 on Monday through 19:00 on Tuesday.
Inside the green line indicates a moderate chance (greater than 40%) that more than 4 inches of snow will fall. The red contour indicates a high chance (more than 70%). Based on this, it looks like we will see several inches of snow across northern Wisconsin and the UP of Michigan by Tuesday evening.