Hail damage swath in South Dakota and Minnesota

By Scott Bachmeier • 4 July 2017

SPC storm report plots, from 12 UTC on 21 June to 12 UTC on 22 June 2017 [click to go to SPC storm reports list]

As seen on the map of SPC storm reports from 21 June 2017 (above), nighttime thunderstorms (during the pre-dawn hours of 22 June) produced a swath of hail (as large as 2.0 inches in diameter) that damaged emerging crops at some locations across eastern South Dakota and southwestern Minnesota (NWS Aberdeen summary).

Nearly 2 weeks later, on 04 July, the hail damage swath was still apparent on GOES-16 imagery. In a comparison of “Blue” Visible (0.47 µm), “Red” Visible (0.64 µm) and Near-Infrared “Vegetation” (0.86 µm ) images (below), the northwest-to-southeast oriented hail damage swath was best seen on the 0.64 µm imagery (in part due to its higher spatial resolution, which is 0.5 km at satellite sub-point); healthy vegetation is more reflective at 0.86 µm, so the crop-damaged hail swath appears slightly darker in those images.

GOES-16 “Blue” Visible (0.47 µm, top), “Red” Visible (0.64 µm, middle) and Near-Infrared “Vegetation” (0.86 µm, bottom) images [click to play animation]

GOES-16 “Red” Visible (0.64 µm, top), Snow/Ice (1.61 µm, middle) and Shortwave Infrared (3.9 µm, bottom) images [click to play animation]

Spectral Response Functions for GOES-16 ABI Bands 3, 4, 5 and 6, along with the reflectance of asphalt, dirt, grass and snow [click to enlarge]

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Aqua MODIS Land Surface Temperature product {click to enlarge]

Regarding the warmer temperatures seen on GOES-16 Shortwave Infrared images, the 1-km resolution Aqua MODIS Land Surface Temperature product at 1738 UTC (above) revealed a 10º F difference between the warmer hail damage swath (which appeared to be about 100 miles in length) and adjacent fields of undamaged crops. A similar result was noted on 03 July by NWS Aberdeen (below).

A comparison of before (21 June) and after (02 July) Aqua MODIS true-color Red/Green/Blue (RGB) images from the SSEC MODIS Direct Broadcast site (below) clearly shows the hail damage path.

Aqua MODIS true-color RGB images, before (21 June) and after (02 July) the hail event [click to enlarge]

Suomi NPP VIIRS true-color RGB image [click to enlarge]

===== 07 July Update =====

The hail damage swath was also evident on a 30-meter resolution Landsat-8 false-color RGB image from 07 July:

Landsat-8 false-color RGB image [click to enlarge]

Landsat-8 false-color RGB image, zoomed in on Castlewood, South Dakota [click to enlarge]

Categories: Aqua, GOES-16, Landsat, MODIS, Other Satellites, RealEarth, Red-Green-Blue (RGB) images, Suomi NPP, VIIRS