The GOES-Sounder RGB Airmass product captured the strong cold front that moved through the Mid-Atlantic on Thursday, 09/15/11. As you can see in the image, the surface cold front was analyzed by HPC at 15z to be ahead of the strong impulse over the Great Lakes. This impulse shows up as the red area and is coincident with the 500 mb trough position as forecasted by the 12z GFS. The blue and red coloring are indicative of the continental polar airmass which has greeted everyone with a taste of Fall. The greenish coloring behind the front is the combination of clouds (whitish) with the cooler air (blue) overlaid. Ahead of the front, you can see the moist subtropical airmass between the coast and the outer cloud bands associated with Tropical Storm Maria.
At a similar time, the MODIS-derived RGB Airmass product captures and validates a similar depiciton of the cold front/shortwave structure about one hour later. I didn’t overlay the model or analyzed data here, but you can plainly see the extent of the dry air over the Great Lakes. The cooler colors reside nearer the MO/IL border as the dry air (red coloring) dominates in this image. Also, notice the dry air impinging on Tropical Storm Maria to the East as extratropical transition has begun in this image.