Updraft: December 24, 2012 Archive

Christmas dash of snow and plenty of cold

Posted at 6:35 AM on December 24, 2012 by Craig Edwards

A dusting of snow is likely in the Twin Cities, central Minnesota and west central Wisconsin this morning, but the light snowfall will diminish as the morning progresses.

Snapshot of radar at 625 a.m CST. Source:NOAA/Weather Underground.

In the wake of the light snow, arctic air will settle over the upper Midwest.

Pressure pattern, surface winds in knots and temperatures. RAP model forecast temperatures for 9 p.m. CST 12/24/2012
Source:NOAA/College of Dupage

A wind chill advisory in in effect for a large part of Minnesota and the eastern Dakotas tonight and Christmas morning. Wind chill readings are expected to register colder than 25 below zero.

Source:NOAA/NWS Chanhassen, MN

Christmas Day will be cold, but travel problems due to icy roads should be confined to side streets. I can attest to the slick, ice covered secondary roads in Wisconsin from traveling back from Chicago on Sunday. While the interstate was clear, once you venture off the main highway, you'll fine plenty of snowcover, especially from the Dells to Janesville, Wis.

Sunday snow depth. Source:NOAA

To refresh your memory, the National Weather Service modified the wind chill formula more than ten years ago. Here's the "new" wind chill chart.

Here's the chart I grew up with. I not-so-fondly recall the wind chill of about 55 below zero on this date in 1983.

OLD Wind Chill ChartSource:NWS

You can learn more about the wind chill formula by clicking here.

When heading out to church services or to visit with family and friends, be sure to dress accordingly. Fashion is secondary. High temperatures will be in the single digits on Christmas Day.

Craig Edwards