Wednesday, January 14, 2009
Take a Look...
Here's an infrared satellite image I grabbed from Wednesday evening at 6:45pm. You can see a line stretching from Maine, West Virginia, through Kentucky, Missouri, all the way past Montana. South of this line the satellite shows a darker image revealing the Deep South, Texas, west to California. However, north the view becomes hazy. Almost opaque. What's happening over the Northern Plains and Upper Midwest that could be causing this differential in appearance?
The devil is in the details, or how much news you've been watching. Look at the key at the bottom of the image. This is a temperature scale. Infrared imagery isn't a true view of clouds like the visible satellite is during the day. IR relies on cloud temperatures to show Meteorologists where clouds are located. Typically clouds temperatures in the atmosphere can fall to -40 to -60 making them easily seen by the coldness of their temperature aloft. However, in this image we're seeing not only clouds, but air temperatures! Yes, the Arctic Blast leaving a trail of cold air from Canada to the United States is so cold that it's able to be detected on IR images! Using the scale we can see that temps of -10 to -25 is being felt from Chicago to Northern Minnesota.