Light snow could affect Friday morning rush

Here's a better look at the forecast map.

That event is expected to last no more than 3 to 6 hours. Snow showers during the day Friday could add another few fractions of an inch before ending around lunchtime, forecasters said.

More light snow is possible Saturday morning as another cold front slips by, but the chances drop to 30 percent.

The prospect of snow and cold overnight temperatures has prompted Baltimore City health officials to declare a Code Blue Health Alert for Friday, opening the city's shelters for extended hours. Outreach workers will also be checking on vulnerable residents.

The forecast calls for even colder weather after the cold front passes on Friday. Lows are expected to drop to near 20 degrees each night through the weekend.

City Health Commissioner  Dr. Oxiris Barbot issued the following statement:

"Baltimore City recorded two deaths last month in which hypothermia was a noted factor. Both individuals were seniors found indoors but without heat. These preventable deaths remind us of the importance of looking out for neighbors, especially the elderly and medically frail who live alone, and those without heat."

Forecasters are still watching for the development of another storm predicted by the models. That one could reach us by Tuesday of next week. The chances are set at 30 percent for now. The forecast track sends it close, or just south of our area. It's way too early to put much stock in the trajectory, but it's a heads up for anyone planning to travel during that period. Keep an eye on forecasts.

The student forecasters at Foot's Forecast see some chance for a bit more snow from the Friday event:

"The snow squall line associated with the cold front will deliver a quick coating to 2" of snow in the Mid-Atlantic. Snow is likely to impact the morning commute on Friday 1/7 resulting from brief periods where some roads, bridges and overpasses become snow-covered.

"This cold front will eventually become an inverted instability trough in the Northeast. A more southern position of this instability trough may bring higher accumulations to the Northern Mid-Atlantic."

Here's AccuWeather.com's take on it.

UPDATE, 6 p.m.: Prof. Jeff Halverson, from UMBC, has checked the latest model runs on the Tuesday storm. Here's his take:

"While today's ECMWF takes the coastal system well to the south and out to sea, the GFS medium range bombs out a low off Hatteras Tuesday, with a swath of 1/2&3/4 liquid over central MD - that would translate into 10+ snow. Jet stream dynamics look impressive. The AVN forms a low off Hatteras, but it looks to be further east and south than the GFS.

"Once again, it's too early to beat the snow drum, and time will tell to see if and how the models line up on this one. Two strikes against a heavy snow scenario include the fact that the NAO is predicted to become positive over the next week or so, and La Nina is generally a heavy-snow killer for the Mid Atlantic.

"But, the metro regions (DC and Balt) did skirt very close to a major snowstorm the day after Christmas. If coastal low tracks show this type of consistency, will this winter season evolve into a series of chilly near misses?"