NOAA/CIMSS ProbSevere for an isolated storm in Nebraska

July 9th, 2014 |
NOAA/CIMSS ProbSevere product, and National Weather Service Warning Polygons, 2302-2334 UTC 9 July 2014 (click to enlarge)

NOAA/CIMSS ProbSevere product, and National Weather Service Warning Polygons, 2302-2334 UTC 9 July 2014 (click to enlarge)

The storm in the animation above produced baseball-sized hail in Nebraska (Visible animation is here, courtesy Dan Lindsey from NOAA at CIRA) although MRMS Mesh Hail sizes were “only” in the 1-inch range (that is, nickel to quarter size). How did the ProbSevere product, which product includes MRMS Mesh size as a predictor, perform?

The visible and infrared satellite animation, below, shows quick development in the absence of cirrus obscuration, and the ProbSevere Satellite components from 2230 UTC are both characterized as ‘Strong’. The model components of ProbSevere (MUCAPE around 2000 J/kg, shear exceeding 30 knots) are also strong. Probabilities increased from 40% to >80% before the warnings for the cell were issued.

MRMS values in this case were not extreme; indeed, when the first warning was issued, MESH was still less than 1″ (but ProbSevere was >80%). Satellite growth rates and environmental information in this case compensated for the modest MRMS Mesh values.

GOES-13 Visible (0.63 µm, top) and Infrared (10.7 µm, bottom) from 2200 UTC 9 July through 0200 UTC 10 July (click to animate)

GOES-13 Visible (0.63 µm, top) and Infrared (10.7 µm, bottom) from 2200 UTC 9 July through 0200 UTC 10 July (click to animate)