ProbSevere and Mature Convection

Just some comments and thoughts being relayed about the use of ProbSevere and mature convection.  The EWP participants have found the ProbSevere model useful in its stated goal--providing probability a storm will first produce severe weather in the following 60 minutes.  In the ProbSevere training it was stated the model will likely have some utility in the application of continued severe threat and/or storm decay because, even after the satellite growth rates are no longer used when the storm is mature--the model continues to generate probabilities using the environmental conditions and the MRMS MESH.  But the model has not been validated in such a manner--so it was really up to participants to comment on utility in those scenarios.  Thus far a clear distinction appears to be emerging:  the ProbSevere output is useful for discrete mature storms like supercells but not so for upscale growth of storms--convective lines.  An example of mature supercells with continued high ProbSevere values valid at 2330 UTC 7 May 2014 near the Red River is shown in the Figure 1.

Figure 1.  NOAA/CIMSS ProbSevere, MRMS composite reflectivity, and NWS warnings valid 2330 UTC 7 May 2014.  This is an example of continued utility of ProbSevere output for mature supercell thunderstorms.

It will be interesting to see if these observations continue through the experiment.  If so, the next generation of training should reflect this distinction.

-Sieglaff