1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible and Infrared Window images (above) included time-matched plots of SPC Storm Reports — which showed supercell thunderstorms that produced several tornadoes, hail as large as 2.50″ in diameter and wind gusts as high as 85 mph across parts of northern/central Illinois and far northwestern Indiana on 11 June 2026. Of the 20 confirmed tornadoes so far across the NWS Chicago forecast area, initial storm surveys have found EF3 damage in Streator, Illinois and Kouts, Indiana.

1-minute GOES-19 Visible and Infrared Window images that included plots of GLM Flash Points (below) highlighted the abundant lightning activity associated with these thunderstorms. Surface observations also supported the satellite depiction of a relatively cloud-free cold pool (created by outflow from a decaying convective complex across northeastern Illinois earlier in the day) — and the upscale growth and tornado production of discrete supercell thunderstorms appeared to increase as they moved eastward and interacted with that residual boundary.

Plots of rawinsonde data from Lincoln, Illinois (location) at 1800 UTC and 2100 UTC (below) displayed a marked increase in the atmosphere’s instability and shear parameters during that 3-hour period — and an elevated mixed layer became well-defined. At the surface, Lincoln was located within the warm, moist air that was surging northward toward the aforementioned residual convective outflow boundary.

View only this post Read Less

1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible and Infrared Window images (above) included plots of SPC Storm Reports — which showed thunderstorms that produced hail as large as 3.40″ in diameter and wind gusts up to 73 mph in eastern Colorado on 08 June 2026.

Farther to the southeast and after sunset, 1-minute GOES-19 Infrared Window images with plots of SPC Storm Reports (below) showed thunderstorms that produced wind gusts as high as 113 mph across Kansas.

View only this post Read Less

1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible images (above) and Infrared Window images (below) included time-matched plots of SPC Storm Reports — which showed thunderstorms that produced wind gusts as high as 98 mph, hail as large as 3.75 inches in diameter and isolated tornadoes across parts of Montana, Wyoming, North Dakota and South Dakota from the late afternoon until a few hours after after sunset on 07 June 2026. Widespread overshooting tops were very apparent in the Visible imagery — and initial discrete storms exhibited enhanced-V signatures in the Infrared imagery, before upscale growth resulted in a large Mesoscale Convective System centered over western North Dakota.

Plots of rawinsonde data in the pre-convective environment at Bismarck ND (KBIS) and Rapid City SD (KUNR) are shown below. Of particular significance were the large Downdraft CAPE (DCAPE) values of 1730 J/kg at 0000 UTC and 1569 J/kg at 1800 UTC at Rapid City and Bismarck, respectively — which highlighted the potential for a strong downward transport of air to surface, producing the widespread damaging winds that were seen across the region.

The coldest cloud-top infrared brightness temperatures in the 1-minute GOES-19 Infrared Window images were around -70C — which represented a significant overshoot of the Most Unstable (MU) air parcel’s Equilibrium Level (EL) as depicted in the plots of rawinsonde data.

View only this post Read Less

1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible images (above) and Infrared Window images (below) showed the development of supercell thunderstorms in parts of southern Saskatchewan and southern Manitoba on 06 June 2026. GOES-19 GLM Flash Points highlighted the abundant lightning activity that was associated with these thunderstorms. The supercell thunderstorms developed in the vicinity of a cold frontal boundary — and produced hail as large as 2″ in diameter, and also prompted the issuance of tornado warnings in both Manitoba and Saskatchewan.

A toggle between GOES-19 Visible and Infrared Window images at 2145 UTC (below) included a cursor sample of the coldest cloud-top infrared brightness temperature of the Manitoba thunderstorm, wich was -68.18C.

A toggle between GOES-19 Visible and Infrared Window images at 2335 UTC (below) included a cursor sample of the coldest cloud-top infrared brightness temperature for the Saskatchewan thunderstorm, which was -68.67C.

View only this post Read Less