1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed thunderstorms that produced a variety of severe weather (SPC Storm Reports) across far southern Oklahoma on 22 April 2020. These discrete supercell storms developed along a cold front associated with a low pressure system moving across the region (surface analyses).

GOES-16 Visible and Infrared images with plots of time-matched SPC Storm Reports are shown below.

Farther to the southeast across eastern Texas, GOES-16 Visible and Infrared images (below) revealed a large and long-lived supercell thunderstorm that eventually moved eastward into Louisiana.

GOES-16 Visible and Infrared images with plots of time-matched SPC Storm Reports are shown below. An Above-Anvil Cirrus Plume was produced by this thunderstorm, and cloud-top infrared brightness temperatures were as cold as -80ºC (violet pixels). Early in its life cycle, after dropping hail of 1.0-2.0 inches in diameter, the supercell produced the fatal EF-3 Onalaska tornado.

A toggle between 1-km resolution NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 2338 UTC (below) provided a more detailed view of the Above-Anvil Cirrus Plume. The coldest cloud-top infrared brightness temperature in the region of the overshooting top was -84.7ºC.

Additional imagery of these storms is available on the Satellite Liaison Blog.

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GOES-16 Clean Window (10.3 µm) infrared imagery, above (click to animate) shows two regions of convection over the southern Plains, one moving through central/southern Oklahoma, one developing over the Texas Panhandle and moving east). A similar (but slightly later) animation of GOES-16 Low-Level water vapor infrared imagery (7.34 µm) is below.

At 0821 UTC, two distinct mesoscale convective complexes are apparent, with a clear region between. This time approximated an overpass by NOAA-20; data from the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) are combined to create NUCAPS soundings.

During this time, there were three soundings launched at Amarillo — at 0000, 0600 and 1200 UTC.  They are shown below and all three suggest steep mid-level lapse rates.

The NUCAPS profile south of Amarillo (in the water vapor image above, the ‘green’ point just south of the ‘red’ point just south of the convective system over Amarillo) is shown below.  It also shows fairly steep mid-level lapse rates.  Click here to see a toggle between the NUCAPS profile below and the 0600 UTC Amarillo Radiosonde.

Gridded NUCAPS fields allow a forecaster to view thermodynamic information from the entire pass more easily than can be achieved by examination of individual soundings, or by viewing soundings via the pop-up SkewT.  The animation below shows the Total Totals index, the 850-500-mb lapse rate, and the lapse rate from 700-300 mb.  Strong instability (Total Totals values around 50) is indicated downstream of the system over the Texas panhandle; also, lapse rates are steeper between 700 and 300 mb (about 7.5º C/km) compared to those between 850 and 500 mb (about 6.8º C/km).

Gridded NUCAPS data gives timely satellite-derived (and model-independent) estimates of the thermodynamic state of the atmosphere.

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GOES-17 (GOES-West) True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) displayed the hazy signature of smoke which was being transported by the circulation of a midlatitude cyclone over the North Pacific Ocean on 21 April 2020.

Since there was no distinct pink-colored dust signal seen in corresponding Dust RGB imagery (below), smoke was the likely airborne aerosol type; recent fire activity in areas such as northern China could have been the source of the smoke.

 

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Just one week after a deadly tornado outbreak across the Deep South, 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) with time-matched plots of SPC Storm Reports (above) showed the development of thunderstorms over Louisiana that crossed the Mississippi border and went on to produce a long-track tornado that produced EF-4 damage on 19 April 2020. Pulsing updraft behavior and the appearance of an Above-Anvil Cirrus Plume was observed with 2 of the thunderstorms as they moved across far southern Mississippi.

Focusing on the 10-minute period 2340-2350 UTC, a sequence of GOES-16 Visible, Infrared and GLM Flash Extent Density (below) revealed a well-defined overshooting top turret which exhibited a minimum infrared brightness temperature of -87.2ºC at 2349 UTC — and a lightning jump where the FED increased to 44 flashes per minute at 2348 UTC. The long-track tornado began about 20 minutes later, at 0010 UTC on 20 April.

Corrected graphic with the correct path length. pic.twitter.com/JoSZPdYHe9

— NWS Jackson MS (@NWSJacksonMS) April 21, 2020

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