Columbian Weather Blogger Steve Pierce said a cold system will move south over the Pacific Northwest on Tuesday followed by overriding precipitation at the coldest part of the day.
"Those are good ingredients for a little snow in Portland and points north on Tuesday," he wrote on his forecast blog on Saturday.
Pierce said the surface low will play a major role in the possibility for snow.
"If the low stays to the north, it will be a brief shot of snow followed by a warm up," he wrote. "If the low stays just south and remains weak (as models have trended) Portland could be in for more snow than even currently modeled."
Pierce said he will update his forecast "as needed."
UPDATE (9:30 a.m. Wednesday) -- Revised forecasts still call for moisture to arrive over the Northwest sometime late Tuesday, bringing a variety of weather conditions to the region. Low-elevation areas may see a rain/snow mix, but anything sticking on the ground is unlikely Tuesday. Showers will continue overnight into Wednesday, with the snow level dropping to about 300 feet, according to the National Weather Service.
Columbian weather blogger Steve Pierce said that Wednesday morning may bring the best chance for low-elevation snow accumulation, but rising temperatures will likely turn precipitation into a snow/ran mix by Wednesday afternoon. The threat of snowflakes in the area will linger until Thursday, according to the weather service.
This much is clear: Much of the region can expect to see snowflakes in the air during the next couple days. Snow on the ground, however, is another matter.
The National Weather Service expects a second dose of late-season wintry weather to arrive Tuesday, colliding with cold air already in place. The equation could bring snowfall down to the lowest elevations, but accumulations, if any, will stick to higher ground. At least that was the Monday afternoon prediction.
The system may put Vancouver and other areas on the snow-rain fringe as temperatures hover just above the freezing mark Tuesday and Wednesday night, according to the weather service. That’s a familiar scenario for the Northwest a formula that makes snow notoriously hard to predict.
“We’re always right on that border. We rarely get that slam-dunk snow,” said Jeremiah Pyle, a meteorologist with the weather service in Portland. “As we get into the tail end of the season, it gets even tougher.”
In Vancouver, the forecast calls for rain and snow Tuesday and Wednesday, as temperatures stay mostly in the 30s. The snow level could drop as low as 300 feet each night, according to the weather service. The chance for flakes will linger into Thursday morning, but likely melt away by Thursday afternoon with an expected high temperature of 46 degrees.
Overall, the system isn’t expected to be a “major accumulating snow event” for low elevations, Pyle said. Areas above 1,000 feet have a much better shot at seeing it stick, he said.
The threat comes on the heels of a system that brought snow to parts of Clark County last weekend, putting a handful of local school buses on snow routes Monday morning. Some places reported seeing flakes as early as Friday evening.
Most of the region can expect the same in the next few days, Pyle said. After that, it’s back to rain and showers later this week, according to the weather service.
For updated weather forecasts and school scheduling information, check http://columbian.com throughout the week.