The atmosphere continues to heat up this afternoon with high low level moisture in place. What we are looking for at this time is the trigger to ignite thunderstorms later today.
Conditions that will come into play are the unstable air, low level shear of the winds (turning from southeast to west as you ascend the atmosphere), a ripple of a middle level pressure trough, and an upper level wind maximum.
Here is the wording on the latest thinking from the Storm Prediction Center as of noon:
THE SEVERE STORMS LIKELY WILL ORGANIZE INTO SEVERAL LARGE CLUSTERS
LATER THIS EVENING AND EARLY WEDNESDAY…MOST LIKELY OVER SOUTHERN AND EASTERN SOUTH DAKOTA AND WESTERN AND NORTHERN NEBRASKA.
ONE OR TWO OF THESE CLUSTERS COULD BECOME LONG-LASTING…WITH THE POTENTIAL TO PRODUCE MORE WIDESPREAD DAMAGING WINDS AND HAIL…AS THEY MOVE GENERALLY EAST INTO PARTS OF IOWA…SOUTHERN MINNESOTA…ILLINOIS AND SOUTHWESTERN WISCONSIN THROUGH DAWN WEDNESDAY.