Mother Nature, who has flexed her mighty muscles this week, seemed to take pity on Utahns Wednesday.

She sent in the clouds.Thanks to the cloud covering, temperatures in the capital city rose slightly, giving residents a temporary reprieve from Tuesday's deep freeze that caused havoc on Utah's highways, in homes and public buildings.

Fog and cold temperatures precipitated a 67-car freeway pile-up, froze and broke water lines and caused isolated power outages throughout the valley.

Officials were forced to close westbound I-215 near I-15 while 31 wreckers towed away wrecked vehicles involved in the massive pileup Tuesday morning. Eastbound lanes at Redwood Road and I-215 were also closed.

More than a dozen people were taken to local hospitals and treated for minor scratches and abrasions, while other victims shivered in the subzero cold.

The unseasonable cold weather was also held responsible for a water pipe bursting in the ceiling of an office at the University of Utah, flooding about a dozen offices in the Student Services Building adjacent to the Park Building.

Dan Waters, assistant director of public safety, said the 1-inch pipe burst about 11 a.m., but officials were unable to find and shut off the main water valve for some time.

"The whole flat area is inundated with water," he said.

Waters said he could not give a damage estimate because some of the carpet, furniture and other items in the offices may be dried out and salvaged. "But then, it could be tens of thousands of dollars," he said.

Officials were not sure of the exact cause, but Waters said a vent in the ceiling where the pipe burst had frozen open and may have caused the pipe to freeze.

In West Jordan, public-works officials said a broken 8-inch main near 70th South and 23rd West was responsible for water shortages that began Sunday morning.

Bob Davis, West Jordan Public Works director, said water pressure had been restored to most affected homes Tuesday night.

The cold also was blamed for three-hour power outages in two sections of Sandy and a 30-minute outage around Second South and 10th East.

Just how cold was it?

William J. Alder, meteorologist in charge of the National Weather Service's Salt Lake office, said it was the coldest Dec. 27 on record; the high at the Salt Lake International Airport was 18 degrees.

The normal high for the day is 37 degrees.

Wednesday, temperatures in Salt Lake rose to the lower 20s, and only a flurry of snow dotted the valley.

However, in the St. George area it was snowing Wednesday morning, prompting National Weather Service officials to issue a snow advisory for the southwest and southern part of the state.

According to Alder, another system on the northwest flow could bring some light snow into the northern mountains Thursday.

Clear skies are expected for Friday, but Saturday Mother Nature will again show she means business.

Alder said it could start snowing by noon, and slop over onto New Year's Day. Several inches of new snow are expected in the valleys, and 1 to 2 feet in the mountains.