A range of flash sizes and energies

A leading-line, trailing-stratiform mesoscale convective system near the triple point in Kansas shows the diversity of flash properties observable from GLM.

The flash properties correspond well to the basic structure of the MCS.
- Leading line: relatively small, frequent flashes
- Trailing stratiform: large, infrequent flashes every other minute or so

Flash extent density in the extensive stratiform discharges are 2 or 3 in some locations, because the GLM flash grouping algorithm tends to split these large flashes.

In total energy, the infrequent stratiform flashes are quite bright. The total light output of one flash equals that of the numerous flashes in the convective line. The large flashes tap an extensive reservoir of charge and discharge it all at once, releasing the electrical energy in the form of light as the channel is heated.

Some of the extensive flashes, such as the one below, show the path of the lightning channel as it crawled through the stratiform region. The brighter trails within the overall flash were long branches of the same flash that were lit up by current flowing along each branch.

The extensive flashes correspond well with expected microphysical trajectories in the stratiform region, propagating from the main convective line, and then bending sometimes north and sometimes south into the enhanced stratiform reflectivity patches of about 40 dBZ. The northerly flashes sometimes follow the curved path implied by the reflectivity pattern to the north of the main convective line.

-Eric Bruning