Bent low-level hodographs in proximity of significant nocturnal tornadoes were associated with 01 km AGL storm relative environmental helicity (SREH) that was on average nearly 2.5-times greater than SREH with curved low-level hodographs. This large difference is especially surprising when considered from a streamwise vorticity perspective, since storm motion in the center of a curved low-level hodograph would contain more streamwise vorticity than would storm motion in the center of a bent low-level hodograph. In order to examine the disparity in SREH, so-called critical angles that appear in the dot product in SREH integrands were computed for each bent low-level hodograph in the sample. The angle between the storm motion vector and the 5 m AGL inflow vector is referred to as the inflow critical angle, and the angle between the storm motion vector and the average velocity vector below the bend height is referred to as the average critical angle. An inflow critical angle of 90-degrees would indicate purely streamwise storm-relative inflow, and an average critical angle of 90-degrees would indicate a large fraction of purely streamwise flow beneath the low-level hodograph bend height. As expected, the majority of critical angles were much less than 90-degrees. Eighty-five (60) percent of the average critical angles associated with significant (weak) nocturnal tornadoes deviated from the purely streamwise situation by more than 20-degrees; eighty-seven (56) percent of the inflow critical angles associated with significant (weak) nocturnal tornadoes deviated from the purely streamwise situation by more than 20-degrees. Nocturnal tornadoes associated with bent low-level hodographs did, however, have 5 m AGL storm relative inflow that was nearly two-times faster than the 5 m AGL inflow with curved hodographs, and this may explain the SREH disparity.
To make better use of critical angles computed by this technique, the storm motion vectors of ordinary storms in proximity of the sampled tornadic storms should additionally be analyzed so that the critical angles of tornadic and ordinary storms associated with bent low-level hodographs can be compared.