Alonsa, Manitoba EF-4 tornado

August 3rd, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface reports; yellow * denotes the town of Alonsa [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the development of a thunderstorm which produced an EF-4 tornado near Alonsa, Manitoba during the early evening hours on 03 August 2018. The cell began to develop southwest of Alonsa around 0020 UTC, and as the thunderstorm matured a series of pulsing overshooting tops could be seen. The haziness evident in the Visible imagery was due to smoke from wildfires in the western US and Canada.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed that the coldest cloud-top infrared brightness temperature of around -70ºC occurred at 0123 UTC (just prior to the time of the tornado).

GOES-16 "Clean" Infrared Window (10.3 µm) images, with hourly plots of surface reports; black * denotes the town of Alonsa [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly plots of surface reports; black * denotes the town of Alonsa [click to play MP4 animation]


The tornado damage path could also be seen in a comparison of ESA Sentinel-2 False Color, Normalized Difference Vegetation Index (NDVI) and Moisture Index Red-Green-Blue (RGB) images (below).

ESA Sentinel-2B False Color, Normalized Difference Vegetattion Index (NDVI) and Moisture Index RGB images [click to enlarge]

ESA Sentinel-2 False Color, Normalized Difference Vegetation Index (NDVI) and Moisture Index RGB images [click to enlarge]

One Response to “Alonsa, Manitoba EF-4 tornado”

  1. Natalie Gordon says:

    Thank you for putting this together. Our property was affected by this tornado (though not our house as we live in the town of Alonsa). Seeing these images is helping me process what happened to us. It was a terrifying experience and these images help explain what I saw.

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