Click and drag the slider button under Set Fade Level to fade between the GOES-11 and NOAA-15 IR images on 27 November 2006 (to quickly toggle between the 2 images, click the middle of the slider bar area, below the word Fade). The 1-km resolution NOAA-15 IR data shows much better detail compared to the "4-km" resolution of the GOES-11 IR image -- note that the coldest air (-40 to -50 C, dark blue enhancement) was confined to the lower elevations of the river valleys across the Yukon Territory, Northwest Territories, and British Columbia; also note the significantly warmer temperatures (-10 to -20 C, orange to yellow enhancement) over the higher elevations of the Mackenzie and Selwyn Mountains, as well as over the snow and ice covered surface of Great Bear Lake.