The first big winter storm of the season is aiming for southern Minnesota just in time to bedevil Thanksgiving travel plans.

Snow is expected to fall starting late Tuesday afternoon, dropping up to 6 inches that will be whipped around by strong winds Wednesday.

With highway travel at risk, the State Patrol has troopers on standby and road crews are ramping up.

"We've got plenty of salt; we've got over 800 plows around the state ready to go as soon as those flurries start coming," MnDOT spokesman Jake Loesch said Sunday night.

Air travel could also be dicey. Delta Air Lines issued a weather waiver for Tuesday flights in and out of Denver, where the storm hits Monday. With waivers, travelers are allowed to make a change to their plans without incurring a fee, according to Delta's website.

The National Weather Service on Sunday issued a winter storm watch for Tuesday night and Wednesday morning for the Twin Cities as well as southern Minnesota and west-central Wisconsin.

"We are two days out, so we don't know where the bull's-eye will hit, but anywhere within that watch area could expect 6 inches of snow," said Brent Hewett, meteorologist with the National Weather Service office in Chanhassen.

His advice: Continue to watch the forecast and be prepared for changing travel itineraries, whether you're driving or flying.

After the storm passes through Colorado and Nebraska, snow is expected to develop across southern Minnesota late Tuesday afternoon, then move across central Minnesota and western Wisconsin overnight. While the snowfall is expected to taper off by Wednesday morning, wind gusts of up to 35 mph could continue to make driving difficult.

"At this time, we are just trying to get the word out early to make sure everyone is paying attention to the weather and planning ahead," Hewett said, adding that the forecast will change slightly in the coming days.

Extra troopers on standby

By Monday night, MnDOT should know more about the storm and will develop more of a plan, which could include pre-treating roads with chemicals to help keep the snow from accumulating.

Loesch encouraged people to call 511, the phone number that reads callers automated travel conditions.

Extra state troopers will be available to stay late or come in early if weather conditions are bad, said Lt. Gordon Shank, spokesman for the Minnesota State Patrol.

Shank said that the first snowstorm of the year "is definitely a good reminder that winter weather driving is here," he said. "Sometimes it catches people off guard."

If you end up going off the road and sliding into a ditch, stay there and call for help rather than trying to drive out yourself, he said. That could result in getting hit. If conditions are bad and you can avoid driving, stay home, he said.

The storm will bring an end to a semi-snow drought for the month. While the Twin Cities area averages about 6.5 inches of snow in November, it's been nearly a decade since a single November storm dropped more than 6 inches of snow on the metro area. So far, only about 1.5 inches has fallen this month.

Thanksgiving week 2010 brought multiple bouts of heavy snow, freezing rain and cold wind. Ice-glazed roads and sidewalks caused crashes and wipeouts across the state.

Another winter storm could develop on Friday into the weekend, though Hewett said it's too early to forecast whether that system will bring rain, snow or a mix. If that develops, it could be the second blow in a one-two punch of winter weather affecting travelers going both to and from their holiday destinations.

"This is the first storm of winter, and it happens to fall on one of the busiest travel times in the country," Hewett said. "So I can understand why people are complaining about this one."