The storm was so severe it temporarily shut down the Salt Lake International Airport. At 9:30 a.m., the heavy snowfall about 4 inches proved too much for the airport's ground crews and runways were closed down.
But about 11:40 a.m. the airport reported one runway was open and flights had resumed. Airport spokeswoman Barbara Gann said crews were working to clear the facility's other two runways and a second runway was reopened Thursday afternoon.
"Flights are resuming," she said, "but we urge customers to check with their airlines for specific flight statuses."
Most of the morning, the airport had stayed open and avoided flight cancellations by alternating runways, keeping one runway open while plowing the others.
"When you reach a certain stage, the Federal Aviation Administration requires this," Gann said. "We were forced to temporarily suspend all operations."
About nine flights in all had been diverted to air strips in Ogden and Provo by 11 a.m., but most flights some 70, according to departure-arrival listings had been cancelled.
About 8:45 a.m., a cargo plane slid a short distance on a taxi-way. That incident did not result in any damage, injuries or runway closures, and did not play into the decision, about an hour later, to suspend operations, Gann insisted.
"It was really a minor incident. The aircraft had cleared the runway, but on the taxi-way slid slightly," she added.
"Actually, we [were] doing pretty well," Gann said, noting that crews had anticipated the icy conditions and pre-treated the runways late Wednesday night. That worked well Thursday, until the snow began its unrelenting fall.
The storm also knocked out power for about 14,000 customers across the state. Jeff Hymas, a spokesman with Rocky Mountain Power, attributed many of the outages to more than a dozen pole fires. The fires were sparked because over several dry days contaminants particularly particulate pollution trapped by the inversion built up on the poles. When the first rain hit during the storm, the pollution mixed with the water and conducted electricity outside of the insulators on the power poles, setting them on fire.
Hymas said salt kicked up by passing cars also contributes to the problem.
The power outages peaked in the early afternoon. By 7:14 p.m., 1,727 customers remained without power in Salt Lake County. Another 804 customers spread across Ogden, Farr West and Huntsville also remained without power Thursday evening. Tremonton also saw some outages, though they ended Thursday evening.
Hymas said crews would work through Thursday night to restore electricity to everyone.
"Our crews have made good progress but we do expect some customers to be without power into the night and possibly over the night," he added.
Power lines down on Highway 201 near Inter state 215 in West Valley City forced detours until early Thursday afternoon. Eastbound Highway 201 traffic was diverted at 3200 West while westbound traffic was detoured around the scene and back onto I-215. Hymas said the lines fell due to weather, though he did not have additional information.
The wet weather also snarled traffic; where traffic was flowing at all on northern Utah's freeways and arterials, it was at sharply reduced speeds. Heeding the treacherous road conditions, drivers on Interstates 15, 80 and 215 in the Salt Lake Valley counted a 25-30 mph pace a blessing, and that extra care was generally paying safety dividends.
"Considering the storm, it's been fairly quiet out there, accident-wise," said Utah Highway Patrol Sgt. Todd Royce. "In spots, the freezing rain has made conditions slippery, and we had a spike [of crashes and slideoffs] about 4 a.m., but it's improved a lot since then. People seem to be taking notice of the conditions."
Still, UHP reported that taking in a pre-storm period beginning at 9 p.m. Wednesday and extending through nearly 11 a.m. About 40 more were reported in Davis County.
Another 30 slideoffs were reported along I-80 in Tooele County, but none of the crashes involved serious injury. Salt Lake County saw 284 crashes throughout the day Thursday. None of the accidents were serious, Royce said.
Royce said even with those figures, the ice and snow could have been much more of a challenge for drivers and the troopers watching out for them.
"Things didn't freeze up nearly as bad as they though it would, and people anticipated the storm better. As a result, we're seeing them driving better and within their abilities given the conditions," Royce added.
In all, Salt Lake Valley law enforcement agencies reported about 70 crashes and slideoffs between about midnight and 1 p.m., public safety dispatchers said.
In Parleys Canyon, eastbound I-80 was initially restricted for semi-trailer rigs to those equipped with tire chains. UHP also restricted travel in both Big and Little Cottonwood canyons to four-wheel drive or chained vehicles.
The National Weather Service reported that 8 inches of snow had fallen in Logan as of 7 p.m. In the Snowbasin mid-bowl station east of Ogden 18 inches fell. Power Mountain reported 17 inches and Alta reported 12 inches; Park City and Solitude saw 8 inches of snow, while the Canyons got 7.
Most schools throughout the region stayed open, though many students arrived late due to buses being delayed. Granite School District did order Robert Frost Elementary School closed for the day, however, when it lost power.
At least the storm systems were clearing the polluted air trapped in Utah's urban valleys by inversions. Thursday's grades from the Utah Division of Air Quality were generally in the "yellow" range, or unhealthy for sensitive groups, but by Friday were to improve to "moderate" or "good."
The Utah Avalanche Center began Thursday with only the mountains above the Salt Lake Valley rating a "considerable" risk for potentially deadly snowslides, but afternoon had elevated risk ratings to "high" for the Ogden, Provo and Uintas districts and "considerable" for Logan and Salt Lake.
Temperatures along the Wasatch Front were to range into the low-30s on Friday with snow expected periodically throughout the day, a mirror forecast of that for Thursday. Overnight lows were to be in the low-20s.
Southern Utahns were getting a break from the harsh weather, though. Highs on Friday were to be in the upper-40s to low-50s the same as Thursday with overnight lows around 30 degrees. There was a slight chance of evening rain as well.
For more forecast information, visit the Tribune's weather page at http://www.sltrib.com/weather.