SAR winds with convection over Lake Superior

May 25th, 2021 |

GOES-16 Band 2 (0.64 µm, “Red Visible”) imagery, 2216 UTC on 25 May – 0126 UTC on 26 May 2021 (Click to animate)

GOES-16 visible imagery, above, shows a line of convection moving over Lake Superior late in the day on 25 May 2021. Merged MRMS Radar Reflectivity at 2340 UTC, below, (from this website) shows radar echoes approaching 45 dBz (at a fair distance from the radars being used to produce the imagery). What kind of surface winds are likely associated with this system in the middle of Lake?

Merged MRMS Reflectivity, 2340 UTC on 25 May 2021 (click to enlarge)

Synthetic Aperture Radar data from the Canadian satellite RADARSat Constellation Mission-3 (RCM3), below, (from this website), shows winds in excess of 50 knots. The winds show a bowing structure as well. RCM data are very useful in lake/oceanic regions where surface data are sparse.

RCM3 SAR Winds over Lake Superior, 2339 UTC on 25 May 2021 (Click to enlarge)

Blowing dust in the Upper Midwest

May 25th, 2021 |

GOES-16 Split Window Difference images, with plots of wind barbs and gusts [click to play animation | MP4]

GOES-16 Split Window Difference images, with plots of wind barbs and gusts [click to play animation | MP4]

GOES-16 (GOES-East) Split Window Difference images (above) showed widespread strong winds across the Dakotas and northern Minnesota which were responsible for producing plumes of blowing dust (darker shades of gray) — most notably from eastern North Dakota into northwestern Minnesota — on 24 May 2021.

The corresponding GOES-16 Split Window Difference images with plots of surface visibility are shown below — at 23 UTC the visibility dropped to 4 miles at Grand Forks, North Dakota as a dense dust plume moved through that location (where southwesterly winds were gusting to 31 knots at that time).

GOES-16 Split Window Difference images, with plots of surface visibility [click to play animation | MP4]

GOES-16 Split Window Difference images, with plots of surface visibility [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images (above) and Dust RGB images (below) created using Geo2Grid highlighted the more dense plumes of blowing dust — the source region for the more prominent dust plumes appeared to be dry agricultural fields in southeastern North Dakota that had received very little rainfall during the preceding week.

GOES-16 Dust RGB images [click to play animation | MP4]

Ground-based lidar data from Grand Forks indicated that the dust was lofted to altitudes of around 10,000 feet.


===== 25 May Update =====

GOES-16 Dust RGB images, with and without plots of surface reports [click to play animation | MP4]

GOES-16 Dust RGB images, with and without plots of surface reports [click to play animation | MP4]

Strong winds persisted across that same region on 25 May — and GOES-16 Dust RGB images (above) again displayed the subtle signature of blowing dust (light shades of pink/magenta) along the leading edge of cloudiness that was moving eastward into northwestern Minnesota.

GOES-16 True Color RGB images (below) once again showed the hazy signature of blowing dust.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]