Hail-producing supercell thunderstorm in Texas

May 7th, 2020 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with time-matched SPC Storm Reports plotted in red [click to play animation | MP4]

As a follow-on to this blog post, we will examine the period following convective initiation and take a closer look at the isolated supercell thunderstorm as it produced a long swath of large hail across far northern Texas on 07 May 2020. 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images with plots of time-matched SPC Storm Reports (above) revealed pulsing overshooting tops as the storm produced hail as large as 3.25 inches in diameter.

In the corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below), the pulsing overshooting tops exhibited infrared brightness temperatures in the -70 to -80ºC range (black to white enhancement).

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

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

In a plot of 00 UTC rawinsonde data from Amarillo, Texas (below) the tropopause temperature was -61.7ºC at the 192 hPa (12.4 km) level — warming was seen directly above the tropopause, but then air temperatures cooled to the -60 to -70ºC range within the 122-100 hPa (15.2-16.3 km) layer. Judging from their infrared brightness temperatures, the overshooting tops likely penetrated into those higher levels.

Plot of 00 UTC rawinsonde data from Amarillo, Texas [click to enlarge]

Plot of 00 UTC rawinsonde data from Amarillo, Texas [click to enlarge]

Slightly longer animations of full-bit-depth GOES-16 Visible and Infrared images from AWIPS (below) showed the storm-top features in better detail. One low-level feature of interest was the brief formation of inflow feeder bands along the southwest flank of the storm during the 0015-0035 time period (rocking animation). The gradual north-northwestward flow of hazy, more humid boundary layer air was also apparent (which likely aided and helped to sustain convective development).

GOES-16 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

A prominent and long-lived Above-Anvil Cirrus Plume (AACP) was seen with this severe thunderstorm — a toggle between GOES-16 Visible and Infrared images at 0105 UTC is shown below. The AACP appeared to exhibit colder infrared brightness temperatures, in agreement with the Amarillo rawinsonde profile at the highest altitudes.

GOES-16 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images at 0105 UTC [click to enlarge]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images at 0105 UTC [click to enlarge]

GOES-16 Visible images with and without an overlay of GLM Flash Extent Density (below) showed how electrically active the storm was. The lighting activity began at 2134 UTC, 1 minute after the cloud-top infrared brightness temperature first became -60ºC or colder.

GOES-16 "Red" Visible (0.64 µm) images, with and without an overlay of GLM Flash Extent Density [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images, with and without an overlay of GLM Flash Extent Density [click to play animation | MP4]


GOES-17 also viewed the storm development, albeit at a 10-minute time increment because west Texas sits outside of GOES-17’s ‘CONUS’ domain. GOES-17’s more oblique view from the allows the satellite to see more structure on the western flank of the system, particularly beneath the cirrus shield! (Click here for a faster animation)

GOES-17 Band 2 (0.64 µm) Visible Imagery, 2000 UTC on 7 May 2020 through 0200 UTC on 8 May 2020 (Click to animate)

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