CIMSS Satellite Blog

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed squall line thunderstorms which produced tornadoes, large hail and damaging winds (SPC Storm Reports) across Oklahoma on the evening of 25 May 2019. Of note was the EF-3 tornado that affected El Reno, Oklahoma which was responsible for 2 fatalities (NWS Norman).

The Infrared imagery revealed evidence of pulsing updrafts (clusters of colder, brighter white pixels) that began to the northwest of El Reno (KRQO) at 0248 UTC — between Watonga (KJWG) and Weatherford (KOJA). Correcting for parallax, this would have moved those pulsing updrafts southeastward, closer to KRQO.

One way of illustrating the magnitude of this parallax shift is to compare SPC Storm Reports at the time of the El Reno tornado — plotting the reports at the actual ground location vs a “parallax-corrected” location which shifts them northwestward to more closely correspond to the 13-km mean height of the storm-top Infrared features (below). The parallax-corrected  El Reno tornado report location is nearly coincident with that of the colder (lighter shade of white) overshooting top.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with surface and parallax-corrected SPC Storm Reports plotted in cyan [click to enlarge]

About an hour after the El Reno tornado, a Terra MODIS Infrared Window (11.0 µm) image (below) displayed cloud-top infrared brightness temperatures as cold as -73ºC.

Terra MODIS Infrared Window (11.0 µm) image, with plots of SPC Storm Reports with +/- 45 minutes of the image time [click to enlarge]

from CIMSS Satellite Blog http://cimss.ssec.wisc.edu/goes/blog/archives/33335