Increased chance of snow.Arctic gusts expected on Christmas Eve

Along: Paul Marsrock, WGN-TV Weather Team


Has been updated:

Light snow continued to fall until Saturday

Snow cover could grow next week as polar air settles in much of the country

As of midnight Saturday, 44.1% of the continental United States had at least an inch of snow. Much of last week’s increase was the result of a massive storm system that took a full week to cross the continent, leaving more than 10 inches of snow on the northern plains and upper Midwest. . A light mass stretched south, reaching northern Illinois and northwestern Indiana.

Most forecast guidance suggests another winter storm is likely later this week. In his GFS model for the National Weather Service, lake enhancements may inflate forecast totals, but Chicago remains on the western and northern fringes of maximum snowfall.

At this point, the timing and location of peak snowfall varies widely between models. This map reflects the consensus on the expected snow depth by 6pm on Friday. This places most of Chicago in an area with 6 inches of snow depth.

Chances of White Christmas in Chicago Increased

Model-predicted probability of snow cover of 4 inches or more in the 12 hours ending at 6:00 PM on Friday, based on the NWS GFS model. A higher probability is indicated east of Chicago, but the number indicated may be inflated due to the possibility of more snowfall on the lake. The same figure from Friday’s model run showed a probability of about 20%.

Arctic blast expected on Christmas Eve

Unlike the uncertainty surrounding snow forecasts later this week, there is high agreement in forecasts for a sharp influx of very cold air from the Arctic on Friday and Saturday. The arrows on this map of predicted temperatures for Saturday, December 24 at 6:00 AM represent low-level wind currents. Subzero temperatures can reach the Ohio Valley and frozen air can reach the Gulf Coast.