Thanksgiving Snow Cover May Bring Single Digit Temps
DENVER (CBS4) - Colder temperatures are a guarantee for Denver this week, but the severity of the cold depends heavily on snow cover starting Wednesday night.
The Arctic region of northwest Canada is the source of this cold air.
Typically, when a cold front moves out of Canada and into the central United States the air modifies along the way. Meaning, temperatures drop as the winds shift north, but conditions aren't as cold as they were at the front's point of origin.
This is because of the milder air that mixes with the Arctic air on its way south.
However, if the ground is covered by enough snow, the airmass doesn't modify as much. As an example, we'll use the cold snap that happened on November 12, 2014.
During this Arctic blast, 2.2" of snow fell at DIA and we only came up with a high temperature of 6 degrees. Later that night, we bottomed out with a temperature of -14 degrees.
Granted, this was an exceptionally cold system, especially by November standards. But the snow-covered ground allowed temperatures to stay closer to their original Canadian values.
Without the layer of snow, warmer soil and surface temperatures allow the new airmass to change by several degrees.
A map from Greencastonline shows Denver's average soil temperature around 40-45 degrees, but this would obviously drop with a fresh layer of snow.
Our Friday morning lows hinge partly on the amount of snow that comes with this system. If it snows a quick inch Wednesday night and Thursday, we'll easily drop into the single digits to start the day Friday.
If we don't accumulate any measurable snow, we may end up in the teens.
Cold is cold, but our chances of making it near zero are higher if there's enough snow to sled on, too.
Justin McHeffey provides nightly reports from the Mobile Weather Lab. He travels Colorado in search of Mother Nature's most powerful and beautiful conditions. Like his Facebook page Meteorologist Justin McHeffey and follow him on Twitter @WeatherMcHeffey.
