The ongoing trouble we’re having with determining an outcome for this system is because it’s a setup that does not move unidirectional, but back and forth. A frontal boundary will sag over the state, potentially sparking showers and thunderstorms on Friday and Saturday.
The overall prospects of severe weather on either day remain relatively weak. Friday especially looks to be an isolated event at best with the Storm Prediction Center only marking off a small 5% risk area (see graphic to the right).
Saturday appears to be just as muddled. A 5% percent risk also exists for this day but mainly to our south and west (see graphic to the left). Of course all of this can change depending on the timing and the eventual position of that frontal boundary.
Sunday is when things could get interesting as the boundary pushes through the state. The trouble, again, is placement and timing. The GFS model wants to push it through the area late, sparking the heaviest convection over the northern portion of Iowa. This would suggest a Minnesota event with a late-stage MCS dragging over eastern Iowa. But, as I’ve said time and time again, timing and placement will be the final guide.
Many risks associated with this weekend will likely not be known until the day of. The fragile forecast associated with exactly where the frontal boundary positions itself and when will largely decide the severe risk for any given point of the upper Midwest, but our chase prospects as well. We will prepare for the unlikely chance of a chase on Saturday, while keeping our attention to the possible outbreak on Sunday.