OKLAHOMA CITY — Oklahoma transportation officials, utility workers and ranchers braced Monday for what was expected to be the season's strongest storm, and even a meeting in Norman to discuss a weather forecasting museum was canceled because of the weather.

The National Weather Service issued a 24-hour winter storm warning for much of the state starting at 6 p.m., with snow accumulation of up to a foot predicted in some parts. In 11 counties in northeastern Oklahoma, a blizzard warning has been issued for 6 p.m. through midnight Tuesday, with forecasters predicting wind gusts of 35 to 40 mph.

The storm system was expected to also bring "life-threatening" wind chills well below zero, Weather Service meteorologist John Pike said.

"We thought we might be able to get through this season without a major storm, but that's not going to happen," Pike said. "There's not a whole lot of freezing rain expected, so that's one good thing about it, but we are getting some pretty strong winds."

Before the storm hit, Gov. Mary Fallin declared a state of emergency for all 77 Oklahoma counties. The declaration gives the state a mechanism to allow local governments to be reimbursed for costs related to the storm. The order also is a first step toward seeking federal aid.

Prior to the storm, Tuesday's scheduled meeting of the National Weather Museum and Science Center at the National Weather Center in Norman was postponed because of the forecast. The organization is working to create a museum focusing on weather-related events and forecasting technology.

All flights scheduled for Tuesday morning at Tulsa International Airport had been cancelled, although spokeswoman Alexis Higgins said crews will work to keep a runway open. Most Tuesday morning flights out of Will Rogers World Airport in Oklahoma City also have been cancelled, spokeswoman Karen Carney said.

The weather also delayed the start of training for the upcoming quarter horse racing meet at Remington Park in Oklahoma City. Officials said the track won't open for training until Friday at the earliest.

Road crews throughout Oklahoma geared up for the oncoming storm. David Meuser, a spokesman for the Oklahoma Department of Transportation, said the agency's 110 salt sheds were fully stocked with 130 tons of sand or sand-salt mixtures. About 1,200 ODOT workers will be available to work during the storm, many for 12- to 16-hour shifts, he said.

The Oklahoma Turnpike Authority also had plenty of salt, sand and magnesium chloride on hand to treat the state's 10 turnpikes, spokesman Jack Damrill said. In Tulsa, the city still has 7,570 tons of salt in its two street maintenance yards, 78 percent of the amount with which it began the winter season, spokesman Michelle Allen said. In Oklahoma city, crews will work 12-hours shifts around the clock until the streets are clear, spokeswoman Kristy Yager said.

The state's major utilities also are "ensuring we have materials and supplies on hand," said Brian Alford, a spokesman for Oklahoma Gas and Electric Co. He said OG&E is paying particular attention to conditions in eastern Oklahoma and northwest Arkansas, where forecasters have said there is more potential for freezing rain.

Wind turbines that generate a portion of the electricity from OG&E and other Oklahoma utilities are computer controlled, Alford said, and will automatically rotate their blades out of the wind and stop turning if gusts reach unsafe levels.

The Oklahoma Blood Institute also launched a mini-blood drive Monday, seeking donations ahead of the storm. OBI officials said blood supplies were adequate for the 150 hospitals it serves across the state, but typical blood inventory ranges from three to five days. That means supplies can run low if the storm results in a significant drop in donations for one or two days.

Farmers and ranchers also worked to prepare their livestock for the weather. Kevin Hafner, who works for Express Ranches' operation in El Reno, said workers prepared enough feed to last their animals for 48 hours. Just before the storm hits, he said, "we'll get bedding down for the babies," in an effort to make sure that bedding is dry.

Cattle will remain outside, he said.

"They are tough enough to handle it," Hafner said. "They've got a good hair coat this year, but we have to have enough feed to give them energy to keep going."

He said workers probably will "have to chop ice" on ponds so that the cattle will have adequate water.

By midday Monday, Oklahoma State University already had called off classes for Tuesday at its main campus in Stillwater and a satellite campus in Tulsa, spokesman Gary Shutt said. Numerous public school systems followed suit or were expected to do so.

Michael Thompson, the commissioner of the Department of Public Safety, said state services will be reduced in seven central Oklahoma counties — including the Oklahoma City metropolitan area — and state employees are being urged to stay at home.

Authorities are discouraging travel during the storm, Oklahoma Highway Patrol Chief Kerry Pettingill said.