Spin up of another tornado from a long-lived supercell

A long-lived supercell thunderstorm transversed across the northern Wichita, KS WFO and into the Topeka, KS WFO Tuesday evening.  This supercell had exhibited ProbSevere All Hazards probability of tornado values that cycled with the intensity of the low and mid level circulation.  Between 2342 UTC and 2358 UTC the probability of tornado increased from near 50% to over 90% as both low and mid-level rotation quickly strengthened (Figure 1).  This storm produced at tornado at 0004 UTC 02 May 2018.  Forecasters have noticed with many of the long-lived supercells, the cycling of probability of tornado values related to cycling of mesocyclone strength.  This is giving forecasters good confidence in how to use the probability of tornado information in their decision making.

Figure 1.  KICT 0.5 degree storm relative velocity and ProbSevere All Hazards probability of tornado 2342 - 2358 UTC 01 May 2018.

-J. Sieglaff