A winter weather advisory could throw a wrench into the evening commute at its peak Friday.

As if the evening commute isn’t harrowing enough, snow could start falling in Maryland by 6 p.m. Friday, making roads icy as temperatures plunge below freezing, according to weather forecasts.

The National Weather Service issued a winter weather advisory that goes into effect at 6 p.m. Friday and should expire at midnight.

Here’s what the forecaster warns in the advisory:

Snow showers are most likely between 6 pm and 8 pm across north-central Maryland into the northern and western suburbs of Washington and Baltimore. Snow showers are most likely between 8 and 11 pm inside the beltways of Washington DC and Baltimore and along and east of the Interstate 95 corridor from the Susquehanna River in northeast Maryland to Fredericksburg, VA.

Areas included in the weather advisory are:

  • District Of Columbia
  • Carroll County
  • Baltimore County
  • Prince George’s County
  • Anne Arundel County
  • Montgomery County
  • Howard County
  • Harford County

With that forecast, Maryland’s State Highway Administration is warning drivers that Friday’s evening commute could be extremely hazardous since plow and salt trucks can’t treat pavements in the midst of heavy traffic. The agency is trying to determine if salt brine application today will be effective at preventing icy roads and urging drivers to change their commute time.

A high around 30 is expected in the region, with a low in the upper teens and a high around 20 on Saturday. The overnight low Saturday will really make Maryland shiver, with single digits expected.