FED Gives Precursor to Strenthening Supercell, but…

Watching the last storm in the line that is still in Illinois, the Flash Extent Density values started climbing rapidly (between 1947Z and 2020Z), which suggested to me that I should start paying attention to it. Upon interrogation, the velocity started to change from being more convergent to rotational, and eventually it appeared that a tornado was likely per the KIND radar. Interestingly, that was when the FED fell rapidly (2022Z).

Clockwise from Top Left: 0.5 KIND Reflectivity, 0.5 KIND SRM, 0.5 KIND Vel, FED

There was also an increase in FED after the tornado signature became less intense, but when it wrapped up again, the FED decreased again (not shown).

Interestingly, I also looked at these same data with the new color curve that Jonathan and Kristin worked on today, and the increase and decreases in FED were not as clear, and I don’t think it would have drawn my attention as quickly. Perhaps the lower values need to be more muted or less bright, but still within the same the rainbow color curve.

Clockwise from Top Left: 0.5 KIND Reflectivity, 0.5 KIND SRM, 0.5 KIND Vel, FED

-Tempest Sooner