Severe weather in Oklahoma, Texas and Louisiana

April 22nd, 2020 |

GOES-16

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

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.

GOES-16 "Red" Visible (0.64 µm, top) and "Clean" Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

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 "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]

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.

GOES-16 "Red" Visible (0.64 µm, top) and "Clean" Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

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.

NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

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

Gridded NUCAPS fields around nocturnal convection over the southern Plains

April 22nd, 2020 |

GOES-16 Clean Window (10.3 µm) infrared imagery, 0346 – 1021 UTC, 22 April 2020 (click to animate)

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.

GOES-16 Low-Level water vapor (7.3 µm) infrared imagery, 0456 – 1441 UTC, 22 April 2020 (click to animate)

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.

GOES-16 Low-Level water vapor (7.3 µm) infrared imagery, 0826 UTC, 22 April 2020, along with NUCAPS sounding points (click to enlarge)

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.

Radiosonde from Amarillo TX at 0000, 0600 and 1200 UTC on 22 April 2020 (Click to enlarge)

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.

NUCAPS Profile at 35 N, 101 W, 0821 UTC on 22 April 2020 (Click to enlarge)

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.

Gridded NOAA-20 NUCAPS estimates of Total Totals index, 850-500 mb Lapse Rate and 700-300 mb Lapse Rate (Click to enlarge)