ProbSevere in SE Missouri

A high CAPE, low shear environment fueled convective development in southeastern Missouri during the early to mid afternoon on 6 August 2014. Rapid convective development was captured using the ProbSevere function as can be seen in this image.

Convective development over SE MO at 1936Z. ProbSevere values of first warned storm are shown. 0.5 degree reflectivity was captured from KLSX.

This image shows the visible satellite imagery of the same storms in southeastern Missouri. The storm had plenty of lightning associated with it as it tracked to the southeast.

Visible satellite imagery of SE MO. Note the numerous lightning strikes over this area.

At 1936Z, the severe probability was nearly 100% for the northeastern most cell. The MESH value was 1.84. The high CAPE environment allowed these thunderstorms to develop quickly (storms had moderate to strong satellite growth rates), and ProbSevere did a good job in diagnosing the cell as ProbSevere had severe probability values jump from 26% at 1930Z to 81% at 1932Z. Shortly after this spike, the NWS in Paducah issued a Severe Thunderstorm Warning at 1936Z.

At the time of this post, there were no severe storm reports that came out of this cell. This might be contributed to the environment not being as favorable for severe weather (the area was in a See Text severe category from the Storm Prediction Center). SPC did issue an MD for the area for sporadic microbursts shortly after the initial warning, and there were a few penny sized hail reports for a cell that developed over Poplar Bluff. The ProbSevere MESH value for that cell was ~1.14, with a ProbSevere value of 90%. The ProbSevere value was at least 90% for that cell for about five minutes prior to the first report of penny sized hail.

Schultz NWS-MKX
Cintineo UW-CIMSS