St. Joseph and the region began preparing Sunday for at least the potential of the season's first measurable snowfall.

The National Weather Service office in Pleasant Hill, Mo., issued a winter weather advisory at midafternoon - forecasting up to 3 inches of snow in St. Joseph and Atchison, Kan., on the southern edge of the oncoming snowstorm. A total accumulation of 3 to 5 inches is possible, with local totals perhaps exceeding 5 inches in areas such as Atchison and Nodaway counties.

"This is one of those weather systems that comes out of the Rockies," said weather service meteorologist Ryan Cutter. "It's not unheard of."

The snow was forecast to develop across far Northwest Missouri and extreme Northeast Kansas late Sunday or early today, and peak around midday. A heavy, wet snow was expected due to relatively warm, moist air wrapping into the storm system, the weather service said. The exact track of the storm was still in flux and was subject to updating overnight, Mr. Cutter said.

"This storm is a very dynamic, compact system," he said. "It could come a little further south."

The storm was anticipated to persist in the area through tonight as the system producing the snow slowly moves out of the region. The weather service's advisory was set for 3 a.m. today through 6 a.m. Tuesday.

The introduction of dry air could also affect the storm's snow-making potency, Mr. Cutter said.

By late Sunday afternoon, officials with the Missouri Department of Transportation had received information from a private forecaster that would lead to road treatment, said spokeswoman Elaine Justus with the District 1 office in St. Joseph. They expect snow to fall heavily this morning.

"Our crews are ready," Ms. Justus said. "We'll be watching it very closely."

Sgt. Becky Caton of the St. Joseph Police Department advised drivers to travel with care and increase their stopping distance for the first snow.

"Just drive slowly when the weather conditions are bad," she said.

Drivers should also use their headlights as they move through traffic in winter conditions, Ms. Caton said.

Warmer road surfaces might not receive as much accumulation, Mr. Cutter said. But snowfall could pile up on bridges, other elevated surfaces and grassy areas, he said.

St. Joseph city streets superintendent Gary Leftin said it's likely that snow will only produce slush on local roads this first time.

"All we've got to do is just page everybody," he said of notifying street crews.

Ray Scherer can be reached

at rscherer@npgco.com.