All of Tennessee needs to be aware of this possible outbreak of severe weather for Wednesday into Wednesday night. The SPC is already talking about this and the NWS for Knoxville who are usually extremely conservative has some pretty strong wording for this far out. This is from the Knoxville NWS.....
“Much uncertainty still exists in the location, type(s), and
magnitude of potential severe weather with this mid-week system.
With respect to the cyclogenesis expected to occur on Wednesday, the
GFS is the most aggressive deterministic model, suggesting the
surface low to strengthen below 995mb as it moves into the lower
Midwest. The ECMWF and CMC guidance are less aggressive with the CMC
holding a more northerly track towards the Great Lakes. The strength
and track of the system is key for efficiency of surface-based WAA
and sufficient instability in our area. In any solution, strong deep-
layer and low-level shear is expected, along with a veering vertical
wind profile. The GFS solution, being most aggressive, suggests
surface-based instability sufficient for organized supercellular
convection Wednesday afternoon into Wednesday night in southern
portions of the area at a minimum. With this solution, a threat for
all types of severe weather exists. However, the ECMWF and CMC
solutions keep instability and convection as elevated with possible
threats for damaging winds and hail. Ensemble solutions also vary
significantly. Ultimately, this system will certainly be something
to watch as we head into next week since potential exists for
notable severe weather across southern portions of the U.S”
“Much uncertainty still exists in the location, type(s), and
magnitude of potential severe weather with this mid-week system.
With respect to the cyclogenesis expected to occur on Wednesday, the
GFS is the most aggressive deterministic model, suggesting the
surface low to strengthen below 995mb as it moves into the lower
Midwest. The ECMWF and CMC guidance are less aggressive with the CMC
holding a more northerly track towards the Great Lakes. The strength
and track of the system is key for efficiency of surface-based WAA
and sufficient instability in our area. In any solution, strong deep-
layer and low-level shear is expected, along with a veering vertical
wind profile. The GFS solution, being most aggressive, suggests
surface-based instability sufficient for organized supercellular
convection Wednesday afternoon into Wednesday night in southern
portions of the area at a minimum. With this solution, a threat for
all types of severe weather exists. However, the ECMWF and CMC
solutions keep instability and convection as elevated with possible
threats for damaging winds and hail. Ensemble solutions also vary
significantly. Ultimately, this system will certainly be something
to watch as we head into next week since potential exists for
notable severe weather across southern portions of the U.S”
