The last 24 hours of model runs have certainly had a few interesting outcomes / trends. A number of factors here that need to be considered for this forecast problem. 1) The Friday trough ... amplitude, speed, etc. ... that is our "50/50" low 2) Shortwave diving through the Midwest around the same general vortex on Saturday morning 2/18 ... some model runs actually keyed in on this s/w to phase (or attempt phasing) with the southern energy 3) More s/w energy in Manitoba within the west side