SEATTLE – After a three-month streak of generally below-average temperatures, the Pacific Northwest is undergoing a radical shift to potentially record-breaking heat this weekend as an intense ridge of high pressure builds into the region.
A warming trend is already underway, but by Sunday and Monday, high temperatures will zoom 30 to 40 degrees above where they sat earlier this week, rivaling typical midsummer highs.
An Excessive Heat Watch covers the over 8 million people who live in the greater Seattle and Portland areas, as well as western Washington and northwestern Oregon, from Saturday through Monday as high temperatures are expected to reach the upper 80s to mid-90s for an area where air conditioning remains scant.
“Get ready to sweat it out, grab a nice cool drink – maybe some lemonade or sweet tea. Borrow some happiness from your neighbors down South because it is going to feel like the South,” FOX Weather meteorologist Britta Merwin said. “We’re taking about a lot of heat moving into the Pacific Northwest.”
The National Weather Service is warning of a major risk of heat-related illnesses in the region’s lowlands and foothills for anyone who does not have access to effective cooling and/or adequate hydration.
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Seattle is expecting highs in the upper 80s on Sunday – which would rate as one of its hottest Mother’s Days, and then a high of around 90 degrees on Monday, which would only be the ninth time the city has reached 90 in May since records began in 1894.
Portland may reach 95 degrees, which would tie for its second-hottest May temperature.
“I think Mom’s going to want to either go to the pool or maybe get closer to the water,” Merwin said. “Keep in mind that if you can get closer to the Pacific, you’ll find some cooler spots, at least on the direct beachfront.”
And while the peak of the heat is pegged for Monday, well-above-average temperatures are expected to hold through the week.
“For the next seven days (after Thursday), we’re pushing the upper 80s to low 90s (in Portland), so this not just a brush of heat, we’re talking about a heat wave in May,” Merwin said.
The rapid warmup will also increase the risk of brush fires across the Pacific Northwest and could trigger an earlier start of the fire season, the NWS warned.
With the timing of the heat over the weekend, officials are concerned many will head to the region’s plentiful and inviting rivers and lakes to cool off.
But after a bountiful winter with a healthy snowpack covering the region’s mountains, the upcoming heat wave will trigger rapid snowmelt, causing the area’s rivers to run high … and cold.
The NWS is expressing serious concern there will be cold-water-related incidents over the weekend and lingering with the heat into early next week and stresses for those heading out on the water to wear a life jacket.
The shock heading from air temperatures in the 90s to water temperatures in the 40s can lead to difficulty swimming, even for experienced swimmers, and can eventually lead to drowning if not wearing a flotation device.