Severe thunderstorms over Wyoming and South Dakota
GOES-16 (GOES-East) “Red” Visible (0.64 µm) images with time-matched plots of SPC Storm Reports (above) displayed clusters of thunderstorms that moved across eastern Wyoming and western South Dakota on 28 June 2020. Numerous overshooting tops were seen, along with cloud-top gravity waves and a couple of Above-Anvil Cirrus Plumes (reference | VISIT training). These storms produced hail as large as 2.25″ in diameter and wind gusts as high as 83 mph.A longer sequence of GOES-16 “Clean” Infrared Window (10.35 µm) images that extended for several hours after sunset (below) showed that some overshooting tops exhibited cloud-top infrared brightness temperatures as cold as -70ºC (darker black enhancement).
The tropopause temperature in 00 UTC rawinsonde data from Rapid City, SD was -63ºC (below) — so the overshooting tops of -70ºC were likely about 1 km above the local tropopause / equilibrium level.