Large hail in Texas

April 6th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with GLM Groups plotted in cyan and SPC storm reports plotted in red [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images with plots of GLM Groups (above) showed a large and electrically-active Mesoscale Convective System (MCS) which produced hail up to 4.5 inches in diameter (SPC storm reports) in eastern Texas on 06 Aprill 2019. These severe thunderstorms intensified generally along and north of a quasi-stationary frontal boundary (surface analyses).

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) showed that cloud-top infrared brightness temperatures associated with the strongest overshooting tops were around -70ºC (dark black enhancement). Earlier that afternoon, a higher spatial resolution Suomi NPP VIIRS Infrared Window (11.45 µm) image at 1950 UTC showed brightness temperatures as cold as -77ºC just northeast of where 2.0-inch diameter hail was reported at Marquez — located approximately midway between station identifiers KLHB and KPSN — at 2015 UTC. Assuming the 00 UTC Lake Charles sounding was representative of the air mass these storms were developing in, the -77ºC temperature would be at an altitude over 1 km higher than the Most Unstable parcel’s Equilibrium Level.

GOES-16 "Clean" Infrared Window (10.3 µm) images, with GLM Groups plotted in beige and SPC storm reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with GLM Groups plotted in beige and SPC storm reports plotted in cyan [click to play animation | MP4]

With better cloud-top shadow contrast, GOES-16 Near-Infrared “Snow/Ice” (1.61 µm) images (below) were helpful to locate the presence of Above-Anvil Cirrus Plume (AACP) features with the 2 strongest cells — and a comparison with 10.3 µm Infrared images indicated slightly warmer brightness temperatures with these AACPs (for example, at 2244 UTC and  0005 UTC).

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm) images, with SPC storm reports plotted in red [click to play animation | MP4]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm) images, with SPC storm reports plotted in red [click to play animation | MP4]

GOES-16 All Sky Total Precipitable Water (TPW) and Convective Available Potential Energy (CAPE) products (below) showed the areal coverage and trends in moisture and instability across the region on that day.

GOES-16 All Sky Total Precipitable Water (TPW) images [click to play animation]

GOES-16 All Sky Total Precipitable Water (TPW) product [click to play animation]

 

GOES-16 All Sky Convective Available Potential Energy (CAPE) product [click to play animation]

GOES-16 All Sky Convective Available Potential Energy (CAPE) product [click to play animation]

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