![](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/05\/GOES-19_RadM2_true_color_night_dust_2025136_213055_2025137_020055.gif\")
<\/a>1-minute daytime GOES-19 True Color RGB images + nighttime Dust RGB images, from 2130 UTC on 16 May to 0200 UTC on 17 May [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>1-minute Mesoscale Domain Sector<\/strong><\/a> GOES-19 (GOES-East)<\/em> daytime True Color RGB images created using Geo2Grid<\/strong><\/a> (above)<\/strong><\/em> showed blowing dust (shades of tan) — lofted by strong southerly thunderstorm outflow winds with gusts as high as 60-70 mph — as it moved northward across northeastern Illinois and northwestern Indiana (and eventually southern Lake Michigan and far southwestern Lower Michigan) during the afternoon and early evening hours on 16 May 2025<\/strong><\/a>. After sunset, Dust RGB images tracked the airborne dust (brighter shades of magenta) as it continued to move farther northward across southwestern Lower Michigan — surface visibility restrictions over that area after sunset were generally 4-5 miles, briefly dropping to 2.5 miles at Benton Harbor (KBEH<\/strong><\/a>) at 0102 UTC on 17 May .<\/p>\n Plots of Wind Barbs and Peak Wind Gusts greater than 50 kts along with Ceiling\/Visibility (below)<\/strong><\/em> showed the northward progression of strongest winds — which began around 2100-2200 UTC<\/strong><\/a> with thunderstorm outflow peak gusts of 60 kts at Champaign (KCMI) at 2104 UTC, 53 kts at Decatur (KDEC) at 2055 UTC and 51 kts at Bloomington\/Normal (KBMI) at 2153 UTC — and lower visibility (1\/4 mi at KBMI<\/strong><\/a> from 2153-2200 UTC, and later dropping to 1\/4 mi at Chicago\/Midway KMDW<\/strong><\/a> from 2340-2345 UTC and then 1\/4 mi at South Bend, Indiana KSBN<\/strong><\/a> at 0020 UTC).<\/p>\n Hourly plots of Surface Wind Barbs (white) and Ceiling\/Visibility (cyan), along with 30-minute Peak Wind Gusts greater than 50 kts (red) [click to play MP4 animation]<\/p><\/div>Plots of 15-minute METAR Surface Reports along with Dust Storm Warning polygons across the greater Chicago area (below)<\/strong><\/em> included the first Dust Storm Warning on record that included the Chicago metro area<\/strong><\/a>.<\/p>\n Plots of 15-minute METAR Surface Reports, along with Dust Storm Warning polygons (light beige) and nearshore Gale Warning polygons (magenta) across the greater Chicago area [click to play MP4 animation]<\/p><\/div>A cursor sample of the Chicago O’Hare (KORD) METAR Surface Report at 0051 UTC on 17 May (below)<\/strong><\/em> listed the unusual combination of a thunderstorm with light rain (-TSRA) and blowing dust (BLDU). Plots of GLM Flash Points at 0045 UTC did show an isolated lighting flash just northwest of KORD.<\/p>\n Cursor sample of the Chicago O’Hare (KORD) METAR Surface Report (cyan) at 0051 UTC, along with GLM Flash Points (white) at 0045 UTC on 17 May [click to enlarge]<\/p><\/div>A Pilot Report east of Chicago Aurora Municipal Airport (KARR) at 0003 UTC on 17 May (below)<\/strong><\/em> indicated that the blowing dust was restricting the Flight Visibility to 1 statute mile at an altitude of 2400 ft (and the vertical visibility was 1700 ft during descent to Aurora). In a plot of surface report data<\/strong><\/a> from KARR, ceilometer data at 0002 UTC depicted the base of the dense dust layer aloft at an altitude 2300 ft (the surface visibility was 1 mile at that time).<\/p>\n<\/a><\/a><\/a>