ProbSevere in a low-topped storm environment

In the mid-Mississippi River valley, storms slowly began popping up in an environment characterized by low MUCAPE and moderate to higher effective shear. Cold air aloft has generated enough instability to initiate storms, however. ProbSevere has generally forecasted 5-30% probabilities of severe for storms in this region (see animation below), exhibiting differing degrees of satellite growth and MESH.

Thus far, only 2 severe hail reports have been recorded in Arkansas. ProbSevere's forecasted probabilities have generally been in a neighborhood you would expect in this environment -- marginal. As might be expected with many storms with low probabilities, few reports have been observed (two severe reports thus far). Several penny to nickel size hail reports and sub-severe wind reports have also been recorded.

The storm with the 1" hail report had a 9% probability of severe (it was not warned by the NWS), and the storm that produced golf ball-sized hail had a 38% probability of severe 7 minutes prior to the report (not shown), and coincident with an NWS warning.

The images below show cases where there have been a some "correct nulls" for ProbSevere. In the first case, ProbSevere only had a 4% probability on a storm in Arkansas, when the NWS issued a warning. It never produced severe-level weather. Similarly, the second case below shows a ProbSevere contour near St. Louis, MO, with only 4% probability of severe when it was warned. No reports were recorded from this storm either.

Example 1:

 Example 2:

-Cintineo