Lake-effect snow in northeastern Minnesota
GOES-13 0.63 µm visible channel images (click image to play animation)
AWIPS images of 1-km resolution GOES-13 0.63 µm visible channel data (above; click image to play animation) revealed the formation of convergence bands withing a weak cyclonic circulation over western Lake Superior on 07 March 2011. These convergence bands were responsible for producing some lake-effect snowfall along the north shore of the lake, over parts extreme northeastern Minnesota — Lutsen reported 8.5 inches of snow, with 5.8 inches falling north of Grand Marais.
POES AVHRR 0.86 µm visible images
A sequence of 1-km resolution POES AVHRR 0.86 µm visible channel images (above) and the corresponding 1-km resolution POES AVHRR 12.0 µm IR images (below) showed a slightly more detailed view of the convergence bands.
POES AVHRR 12.0 µm IR images
A comparison of 1-km resolution POES AVHRR Cloud Optical Depth products at 18:41 and 19:18 UTC (below) showed that the primary convergence band along the eastern side of the cyclonic circulation feature exhibited significantly higher cloud optical depth values (blue to cyan color enhancement).
POES AVHRR Cloud Optical Depth product images
===== 08 MARCH UPDATE =====
Another well-defined vortex was observed over northern Lake Superior on the following day. A comparison of 250-meter resolution MODIS true color and false color Red/Green/Blue (RGB) images from the SSEC MODIS Today site (below) showed the vortex cloud feature with a very long and narrow “tail” extending southward and westward from the center of the circulation, along with a complex ice structure across the far southern portion of Lake Superior. Ice and snow cover appear as cyan-colored features on the MODIS false color image, in contrast to supercooled water droplet clouds (which appear as brighter white features).
MODIS true color and false color images