ProbSevere v3 (PSv3) has shown a consistently higher signal than ProbSevere v2 (PSv2) on storm near Scottsbluff, NE. PSv3 was 20-40% higher during the development stage and as it matured. PSv3 also had consistently (and correctly) lower tornado probabilities than PSv2. The elevated tornado probabilities was likely a result of very high MRMS azimuthal shear, which was a result of sidelobe contamination. In this case, ProbTor v3 correctly didn't emphasize the azimuthal shear as much as PTv2. ProbHail v3 has been the highest hazard probability, whereas ProbWind v2 was the highest for version 2. One forecaster noted that v3 is definitely picking up on the hail threat better than v2. Hail up to the size of 1.5"-diameter has been reported thus far. Forecasters have noted that the higher PSv3 values seems to correlate better with their expectations of the storm.
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| Figure 1: ProbSevere v3, MRMS MergedRef, and NWS severe weather warnings for a storm near Scottsbluff, NE. |