Lubbock, Texas Severe Hail with ProbSevere

The weather this afternoon was quiet for much of the operations period, but in the afternoon thunderstorms developed along the dryline in the Lubbock, Texas WFO.  Initially storms pulsed (strengthened but then subsequently weakened) with ProbHail values in the 50-60% range.  Figure 1 below shows progression of a weak thunderstorm that slowly strengthened between 2226 and 2238 UTC (ProbSevere values ~20-35%) and then rapidly strengthened from 2240 - 2256 UTC (ProbHail and ProbWind values both first exceeded 80% at 2256 UTC).

Figure 1.  MRMS Composite Reflectivity and ProbSevere (All Hazards) 2226-2312 UTC 30 April 2018.  

The storm continued to strengthen with ProbSevere values in excess of 90%.  At 2313 UTC (1 minute after the final frame of the animation) 1.5" hail was reported by a trained spotter.  This example shows how ProbSevere can provide lead-time ahead of severe hazards (ProbSevere exceeded 80% 19 minutes before the first severe hail report)--which can increase forecaster confidence and lead-time in issuing severe thunderstorm warnings.

-J. Sieglaff