30-second imagery of severe thunderstorms across the Mid-South and Deep South
Overlapping 1-minute Mesoscale Domain Sectors from GOES-16 (GOES-East) provided imagery at 30-second intervals during an outbreak of severe thunderstorms (SPC Storm Reports) across parts of the Mid-South and Deep South on 09 December 2023. “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) included time-matched plots of SPC Storm Reports for a thunderstorm that produced a EF3-rated tornado which was responsible for 3 deaths and 62 injuries in the Clarksville, Tennessee (KCKV) area. The coldest cloud-top 10.3 µm infrared brightness temperatures were in the -60 to -65ºC range (darker red enhancement).1-minute GOES-16 Visible and Infrared images with/without an overlay of GLM Flash Extent Density (below) showed pulses of cold overshooting tops (brighter white infrared pixels) and brief lightning jumps associated with the Clarksville supercell thunderstorm as it moved across Montgomery County in Tennessee into Todd County in Kentucky.
30-second GOES-16 Infrared images (below) showed a later thunderstorm that produced a EF2-rated tornado which was responsible for an additional 3 fatalities in Madison, Tennessee (just north of Nashville KBNA). 1-minute GOES-16 Infrared images with/without an overlay of GLM Flash Extent Density (below) showed lightning activity associated with the thunderstorm that produced the Madison tornado (in Davidson County) — as with the Clarksville storm, pulses of cold overshooting tops and brief lightning jumps were observed as the tornadic thunderstorm progressed across the area. Cursor sampling of 2-km resolution GOES-16 10.3 µm brightness temperature along with the operational Cloud Top Temperature and CLAVR-x Cloud Top Height derived products for the Clarksville TN tornadic thunderstorm and the Madison TN tornadic thunderstorm (below) indicated that Cloud Top Temperatures were in the -65 to -66°C range, with Cloud Top Heights in the 43000-45000 ft range (the CLAVR-x Cloud Top Height product was shown here, since its 2-km resolution was superior to the legacy 10-km resolution Cloud Top Height product currently available in AWIPS).Those GOES-16 Cloud Top Temperature and Cloud Top Height values were a bit colder/higher than the Most Unstable air parcel Maximum Parcel Level (MU MPL) calculated using rawinsonde data from Nashville, Tennessee rawinsonde data at 1200 UTC on 09 December, shown below (source). Unfortunately, a 0000 UTC / 10 December Nashville rawinsonde report was not available. A larger-scale view of 30-second GOES-16 Infrared imagery is shown below, spanning the ~13-hour period from 1900 UTC on 09 December to 0752 UTC on 10 December — which depicted more of the nighttime SPC Storm Reports across parts of northern Mississippi, Alabama and Georgia. Many of these severe thunderstorms were developing within a corridor of moisture and instability ahead of an advancing cold front, as seen in 5-minute GOES-16 Visible images combined with Total Precipitable Water and Lifted Index / CAPE Derived Stability Indices in cloud-free skies (below).