English: An example of a detection system to identify sting jet occurrence using downdraft slantwise convective available potential energy.

Original caption

"Methodology example using the ERICA IOP4 storm as represented in ERA-I. (a) Sting-jet DSCAPE precursor (color shading), 850-hPa θw contours (colored; every 2 K starting at 277 K in blue) and MSLP (gray contours every 3 hPa) with RH > 90% in the lower midtroposphere (considered in the layer from 600 to 850 hPa) in gray shading to indicate the cloud head. Northeastward cyclone movement is indicated by system track (thick black line). To satisfy the precursor diagnostic DSCAPE values must be proximate to the cyclone center (within a circle of radius 700 km) and within the rearward-developing cloud head (clear sector in circle bounded from 100° to 300° when 0° is defined as the direction of cyclone movement). (b) Resolved wind speed (850 hPa) separated into cool- and warm-sector resolved winds (blue and red shading, respectively) by a θw threshold (284 K; black line). This threshold is the mean θw value obtained from grid points exceeding the 99th percentile of ∇θw (gray shaded areas) within a 1000-km radius of the cyclone center."