RADARSAT Constellation Mission 3 (RCM3) Synthetic Aperture Radar (SAR) wind data over southern Lake Michigan at 1201 UTC on 28 June, above (click to enlarge, taken from this website), shows a small region of strong winds just offshore of southeast Wisconsin and northeastern Illinois.  GOES-16 Band 2 visible imagery (clipped from the CSPP Geosphere website, click here for the direct link to the imagery — valid until mid-July) shows modest convection just off the Wisconsin/Illinois shorelines.

Winds from the Sullivan WI (WFO MKX) radar, below, (courtesy John Gagan, SOO), show a similar structure. The challenge in comparing the SAR winds and the radar winds: The Sullivan radar beam in that location is about 5000 feet above the surface. Storm-relative velocities are about 20 kt.

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The animation above shows convection over the south Pacific to the east of American Samoa (note the Manu’a Islands just east of 170 W Longitude in the animation). Extensive cloud cover will limit the ability of the GOES-17 instrument to detect low-level cloud motions underneath the deep convection, which motions can be used to infer wind speeds. Other data sources are needed. In addition to scatterometry from the MetOp series of satellites, synthetic aperture radar (SAR) that flies on the RADARSAT Constellation Mission (RCM) satellites (and on Sentinel) (available at this website) can give high-quality estimates of wind speeds. Given the animation of full-disk imagery above (at ten-minute timesteps), taken from AWIPS and therefore sub-sampled down to 6-km horizontal resolution, how fast would you guess wind speeds might be near the surface under the convection. SAR data below shows winds near 25 m/s, i.e., storm-force winds, under the convection.

A full-resolution image of GOES-17 clean window infrared data (10.3 µm) (created using Geo2Grid) is shown below, at the closest time to the observed winds shown above. The deepest cloud tops are close to the strongest surface wind speeds.

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GOES-17 (GOES-West) Shortwave Infrared (3.9 µm) images (above) included plots of hourly surface temperature during the 26 June – 27 June 2021 period — the first 2 days of a historic heatwave across the Pacific Northwest (caused by an anomalous 500hPa ridge over the region). Numerous high temperature records were set, including new all-time record highs for Portland OR (116 F), Seattle WA (104 F) and the entire country of Canada (121 F).

GOES-17 True Color RGB images created using Geo2Grid (below) showed that most of Washington and Oregon remained cloud-free during the daytime — and a smoke plume from the Lava Fire in far northern California was seen drifting northwestward (especially on 27 June).

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GOES-16 (GOES-East) “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm), Shortwave Infrared (3.9 µm) and Fire Temperature RGB images along with Fire Temperature, Fire Power and Fire Area derived products (above) showed reflectance and thermal signatures of sunlight reflecting off large arrays of solar panels at solar farms across southern/central Minnesota on 23 June 2021. These bright/warm signatures were more pronounced from larger solar farms — with the warmest being exhibited by a solar farm southeast of Redwood Falls in southwestern Minnesota (Shortwave Infrared: 50.6ºC / Fire Temperature: 853.9 K / Fire Power: 126.8 MW).

The Fire Temperature / Fire Power / Fire Area derived products are components of the GOES Fire Detection and Characterization Algorithm (FDCA).

Previous blog posts discussing solar farm signatures can be found here, here and here.

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