Lightning-related fatality in Wisconsin

By Scott Bachmeier • 15 April 2026

1-minute GOES-19 Infrared (10.3 µm) images with plots of GLM Flash Points (white dots) and METAR surface reports (cyan), from 2301 UTC on 15 April to 0100 UTC on 16 April [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Infrared images (above) included plots of 1-minute GLM Flash Points (which are parallax-corrected to correspond to their surface locations) — and showed an increase in thunderstorm coverage and lightning activity across southeastern Wisconsin late in the day on 15 April 2026.

Unfortunately, one lightning-related fatality occurred south of Pewaukee, Wisconsin around 0043 UTC or 7:43 PM Central Time (Local Storm Report). A cursor sample of a GLM Flash Point just southeast of Pewaukee (below) revealed a rather large flash area of 1114 km² at 0041 UTC (7:41 PM Central Time).

GOES-19 Infrared (10.3 µm) image at 0041 UTC on 16 April, with a cursor sample of a GLM Flash Point (white dot) near Pewaukee, Wisconsin [click to enlarge]

1-minute GOES-19 Infrared images with contours of ProbSevere LightningCast probability (below) indicated that the LightningCast probability over Pewaukee was consistently at or above 90% beginning at 0015 UTC.

1-minute GOES-19 Infrared (10.3 µm) images, with an overlay of LightningCast probability contours, from 2340 UTC on 15 April to 0100 UTC on 16 April [click to play MP4 animation]

A plot of LightningCast Probability and GOES-19 GLM Flash Count (below) revealed that the LightningCast Probability was 73% or higher during the 30-minute period preceding a marked increase in GLM Flash Count in the vicinity of Waukesha County Airport (KUES, which is located about 3 miles south of Pewaukee).

Plot of LightningCast Probability and GOES-19 GLM Flash Count in the vicinity of Waukesha Airport (KUES) [click to enlarge]

Categories: GLM, GOES-19, Lightning, LightningCast, ProbSevere, RealEarth, Severe convection