Cloud streets and ice across Hudson Bay, Canada

December 15th, 2011 |
MODIS true color RGB image + MODIS false color RGB image

MODIS true color RGB image + MODIS false color RGB image

A comparison of a MODIS true color Red/Green/Blue (RGB) image with the corresponding MODIS false color RGB image of Hudson Bay, Canada on 15 December 2011 (above) revealed the following: (1) most of the northern and western portions of Hudson Bay were ice-covered (the ice appeared bright white on the true color image, and darker shades of red on the false color image) and (2) thee false color image made it easier to discriminate between the ice (darker red) and a diverging pattern of supercooled water cloud streets (white to cyan colored features) which were aligned in the direction of strong boundary layer winds in the wake of a cold frontal passage. The horizontal convective rolls that created these cloud streets may have also contained significant amounts of blowing snow.

AWIPS images of MODIS false color RGB images with overlays of METAR surface reports (below) showed that winds were gusting as high as 33 to 38 knots at stations along the western edge of Hudson Bay.

MODIS Red/Green/Blue (RGB) false color images

MODIS Red/Green/Blue (RGB) false color images

McIDAS images of GOES-13 0.63 µm visible channel data (below) showed that the strong winds were acting to move large portions of the ice, which according to the Canadian Ice Service was still fairly young “gray” (5-15 cm thick) to “gray-white” (15-30 cm thick) ice.

GOES-13 0.63 µm visible channel images

GOES-13 0.63 µm visible channel images