Working on the DSS for the PGA tournament, one of the more frustrating features was how thunderstorms well outside the range of the event produced lightning. About the time one DSS image was sent, there was a lightning flash that occurred well north of the primary cluster and near a very weak area of reflectivity.
However, this has been the story for much of the day, where intense convection has been to the south and weaker cells to the north are still managing to produce lightning. Below is the probability of exceeding 10 flashes on GLM, with GLM and MRMS at -10 C to highlight how weak the convection was to the north. The fact that reflectivity was barely at 25-35 dBZ would suggest little potential for lightning.
Analyzing the RGB channels for lightning, one can see this evolution well. With more intense updrafts producing several flashes on GLM, they appear yellow. To the north, where it appears the anvil is carrying charge north, the flashes are very long. From a DSS perspective, this can be frustrating when communicating the potential for high impact weather when all that one gets are sprinkles and rumbles of thunder. Still, the RGB channel can be very helpful in delineating these features, but would also be a helpful means to suggest that the northern convection may not develop quite as much. The 50dBZ echo tops are intended to help highlight the stronger storms. Note how a few pixels of 50dBZ echo tops at best appear in the blue, while the larger cluster of taller storms have the younger convection. This also helped me consider parallax as well. Overall, I really like the potential for lightning characteristics divided into this RGB would be helpful in pulse convection.
And then later, the LightningCast began to behave a bit more oddly. Perhaps these situations cause it to become bouncy. Although, you can almost see these dips in the flashes on the chart as well. At this stage, I feel like I could tell the poor folks playing above par at the PGA tournament and taking forever that they can pack up their clubs and head home, because at this stage, the lightning is here to stay.
Outside of the one flash of lightning that took place over the event about when values crept upwards towards 50 percent, there was a flash. However, values had been hovering around 30-40 percent for much of the day. Values crept even higher, and yet there were no flashes nearby. It seems whatever convective debris left the region, and then the forecast became better overall.
Kadic