Windchill Advisory In Effect Through Sunday

BALTIMORE (WJZ) -- A Wind Chill Advisory is in effect for most of Maryland until Sunday at 6 a.m.

WJZ's Meg McNamara says the Baltimore area topped out at a high of 18 degrees today, and most of the area is expected to hover around zero tonight.

"We didn't end up matching this morning's record of 5 degrees -- because we only made it down to 7 -- but I think tonight the cold is definitely going to be record breaking," McNamara said.

A weak storm system will cross the region Monday and Monday night.

"Monday may see some midday snow, sleet or freezing rain," McNamara said.

Pacific high pressure will build across the region Tuesday, then move out across the coast Wednesday. Another storm system may affect the region late in the week.

The Baltimore City Health Department has extended the Code Blue Alert that was originally issued on Christmas night to Monday morning.

The deep freeze has created major problems for an aging infrastructure. Dozens of water main breaks have cropped up across the area -- so much so that the Department of Public Works can't keep up. DPW issued mandatory, 12-hour overtime shifts without leave beginning Friday.

Follow @CBSBaltimore on Twitter and like WJZ-TV | CBS Baltimore on Facebook