Lake Surface Temperatures in the Great Lakes in mid-June
Lake-surface temperatures over the Great Lakes, 0747 UTC on 16 June 2021
Mostly clear skies over the Great Lakes early in the morning on 16 June allowed the VIIRS instrument on Suomi-NPP an unobstructed view of the surface waters. Advanced Clear-Sky Processing for Oceans (ACSPO) Lake-surface temperatures, above, show the temperature distributions in the five lakes. The warmest region is western Lake Erie where water temperatures are already in the 70s. Saginaw Bay in Lake Huron (and Green Bay in Lake Michigan — although clouds at this time prevented a good view) are also in the 70s. Much of Lake Superior remains around 40 F; Lake Michigan is unusually warm — with a large region of 60+ — following an early-season heat wave (graph from GLERL’s Lake Statistics webpage).
Clear skies continued into the afternoon of the 16th; the true-color image, below, derived from VIIRS data from NOAA-20 shows cloud over Lake Huron and some sun glint over Lakes Michigan and Superior. A zoomed-in view of Lake Erie (link) shows remarkable detail to the water color in the lake.
VIIRS True-Color image over the Great Lakes, 1819 UTC on 16 June 2021 (Click to enlarge)
Suomi-NPP and NOAA-20 VIIRS data were downloaded at the CIMSS Direct Broadcast site and processed using CSPP software. Great Lakes SST fields and VIIRS imagery over CONUS are available via LDM feed to National Weather Service Offices. True-Color imagery can be found at VIIRS Today and at the CIMSS direct broadcast ftp site.