Clark County’s extended cold snap briefly thawed Tuesday, as temperatures climbed above freezing in places for the first time, day or night, in nearly a week.
But the threat of wintry weather hasn’t subsided just yet, according to the National Weather Service in Portland.
After a mostly dry day today, the region could see freezing rain on Thursday, forecasters said. But freezing rain, like other winter precipitation, needs a particular recipe to materialize.
As moist air gradually warms the region from above, lingering cold air will remain in place in lower elevations, said weather service meteorologist Beth Burgess. If that cold air mass stays in place long enough — and stays cold enough — it could produce freezing rain and ice accumulation. If it doesn’t, the region gets wet, but no ice.
“We’re very certain about precipitation,” Burgess said. “We’re just very uncertain about low-level temperatures.”
The transition will eventually lift Clark County out of a run of extreme cold that has gripped much of the country this month. Wind and pressure patterns have funneled a pipeline of Arctic air to the U.S. from the north, Burgess said. And because colder air is more dense and heavy, it can be difficult to budge once it’s in place, she said.
When temperatures edged above freezing at Vancouver’s Pearson Field on Tuesday, it broke the longest streak of days at or below freezing in more than two decades, said Steve Pierce of Northwest Weather Consultants. The afternoon high of 34 degrees was the first above freezing since Dec. 4, six days earlier. A longer streak occurred in December 1990, Pierce said.
The thaw arrived only after wintry conditions caused another round of closures and delays across the county.
Icy roads and snow prompted several school districts to close for the day, while start times in the Vancouver and Camas districts were delayed. Evergreen Public Schools, the county’s largest district, started on time.
The Green Mountain School District on Tuesday night announced school would start two hours late.
In Vancouver and elsewhere, crews continued to respond to water problems from damaged pipes in record-setting cold. At one point, Vancouver Public Works received 51 calls from homes and businesses with freezing or bursting pipes in a 48-hour span, according to the city. Similar calls continued to pour in Tuesday, officials said.
Warmer conditions, with regular old rain, are expected to return by this weekend. Temperatures should land in the 40s by Saturday, or close to normal for this time of year.
Columbian staff writers Erik Hidle and Susan Parrish contributed to this story.
