This was an interesting case where the storm split and the ENI data highlighted the stronger southern cell which was very beneficial in the warning process.

The ENI products all worked beautifully in this case. Initially, I noticed a slowly increasing trend in Prob Severe around 2346Z over the cell. By 2355Z, I noticed that there was an ENI DTA Thunderstorm Alert on the storm. At 0000Z, the ENI DTA Thunderstorm Alert increased to Significant and the Prob Severe split into two ovals since the storms had split by this point. By 0007Z, I  began to see that the southern storm had become the stronger of the two cells as the severe prob had increased to 72% while the northern storm prob severe was only at 42%. At 009Z, prob severe on the southern cell increased to 90% while it was still only 42% on the northern cell. At this point, I decided to go ahead and pull the trigger on the severe thunderstorm warning for the southern cell. Knowing that the prob severe was much lower on the northern cell increased my confidence that I should only include the southern cell in my warning polygon. The warning took a long time to get out due to some technical difficulties, so I didn’t get the lead time that I would have liked, but the warnings did verify. There was a report of 1.25” hail at 7:25 PM, 2” hail at 7:23 PM and 1” hail at 7:52 PM.

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The ENI time series data was also helpful in this case as it showed lightning jumps around the same time I was seeing other signs of intensification. This increased my confidence that the storms were indeed intensifying and that a severe thunderstorm warning was needed.

-Helen Hunt