By Linda Weiford, WSU News
PULLMAN, Wash. – The calendar says it’s September but it’s about to feel like July as temperatures surge well into the 80s and 90s over much of the Pacific Northwest. By Saturday, many locations will be baking in heat that’s 10-plus degrees above average for this time of year, according to meteorologist Nic Loyd of Washington State University’s AgWeatherNet.
The “monster ridge” of high pressure that had parked itself over the West Coast – contributing to record high temperatures and drought conditions – is back, he said.
This means Washington temperatures are expected to creep toward 100 degrees in Yakima and the Tri-Cities and hit 94 in Walla Walla and 87 in Spokane and Pullman, according to weather prediction models. Seattle is forecast to reach 82 degrees and Lewiston, Idaho, the mid-90s.
“For a short time, cool, dense air moved in and displaced that persistent ridge,” said Loyd. “Now it’s returning from southwest of us. There’s no question, the monster ridge is back.”
Last week, a cluster of churning tropical storms in the Pacific Ocean helped break up the ridge, bringing cooler temperatures and even some badly needed rain to the region. But the massive, advancing high pressure system “tells us that the pattern shift was only temporary,” Loyd explained.
And though the ridge and its accompanying warm weather may mean trips to the beach, hikes in the hills and outdoor barbecues, it does have its downside. Washington state, already struggling with recording breaking hot spells, drought and wildfires, “needs relief that’s long-term,” said Loyd.
“Unfortunately, I think there’s a strong chance that dry conditions and above-average warmth will extend through winter,” he said.
For now, the region’s latest hot spell is expected to start waning by Monday, when temperatures will dip closer to normal for mid-September.