The first real blast of cold air of the 2011-2012 cold season over northern and central NM moved into the eastern plains on Saturday December 3rd. This cold air was reinforced by a significantly colder arctic front that pushed west through the Rio Grande Valley and into western NM through Monday December 5th. Cold saturated low level air and upslope flow across the region behind the first front produced widespread freezing fog Sunday morning December 4th. The animated gif below shows the development of freezing fog across the high plains and Rio Grande Valley on the GOES low cloud base and fog depth product. A freezing fog advisory was issued late Saturday evening as numerous reports of visibilities to 1/4SM and hazardous interstate travel were reported. Click image to enlarge and loop.
Meanwhile farther to the west a deep upper level low pressure system was approaching NM. Moist cold upslope flow and upper level forcing created our first widespread major snow storm of the season. Many areas picked up 6 to 12″ of snow with up to 15″ in the higher terrain and drifts up to 3 feet. Areas within the ABQ metro area also saw snow with up to 7″ reported on the west side. Downslope flow in areas such as Raton and the ABQ east side below canyons produced our pesky snow shadow. Note the MODIS 1km false color imagery shows areas with widespread snow cover in red and snow shadowed areas in green.