Click on the animated gif below to see how the lightning jump algorithm increased from 0 sigma at 2210Z to 4 sigma at 2211Z to 8 sigma at 2212Z. This was a great clue that the updraft of the storm was strengthening and that a warning may be necessary. We used this information in conjunction with the Prob Severe which was showing an increasing trend to go ahead and pull the trigger on a severe thunderstorm warning. It was interesting that although Prob Severe was showing an increasing trend, it was not over the 80% threshold. In this case, the lightning jump algorithm alerted us more than Prob Severe whereas we’ve seen other cases today where Prob Severe has been high and the lightning jump algorithm has been lower than expected.

-Helen Hunt