By Linda Weiford
While the 45-50 degree weather predicted mid-week in parts of the Pacific Northwest will bring long-awaited relief from frigid temperatures, snow and freezing rain, the warmup could trigger creek and river overflow and landslides, said meteorologist Nic Loyd of Washington State University’s AgWeatherNet.
“The good news is that it will be the warmest weather we’ve had since November. The bad news is that it could get messy. The reversal will be significant and quick, not gradual,” he said.
Across much of Washington state, temperatures are expected to reach the mid-40s, including in Pullman, Spokane, Yakima and Wenatchee. Meanwhile, the mercury could nudge 50 in the Tri-Cities, Clarkston and Seattle.
The rapid thaw — likely to be sped up by periods of wind and rain, should begin on Tuesday and peak on Wednesday and into Thursday. Large amounts of water from melting snow and rainfall could trigger localized flooding, accelerated soil erosion and washouts, Loyd explained.
“The weather system is expected to arrive on the heels of a stretch of unusually cold weather and significant snowfall east of the Cascade Mountains. Because the ground is still cold, it will be hard for it to absorb the snowmelt and rain so quickly,” he said. “This creates the perfect combination for pooling water, rising creeks and streams.”
Unlike the severe, freezing weather systems that have been swooping into the region from the Gulf of Alaska since early December, this new system is a ribbon of warm, wet and windy air arching its way from the subtropical waters of the Pacific, he added.