Maybe 80 degrees in June doesn’t sound like cool relief. But after the scorcher expected Wednesday — when the high is predicted to hit 90 in the interior of Western Washington and 87 in the Seattle area — it may feel like a respite.
Several places in Western Washington broke temperature records on Tuesday. Seattle-Tacoma International Airport hit 87, three degrees higher than the record set in 1989. Olympia notched 87, one degree higher than its 1989 record. And Quillayute, Clallam County, soared to 91 degrees, shattering its previous record of 77, set in 1999.
Seattle tied its previous record, with the National Weather Service station recording 80 degrees, which it last saw in 1989.
Temperatures are expected to hit the high 80s or low 90s through much of the Puget Sound region on Wednesday, weather service meteorologist Kirby Cook said Wednesday morning. However, some midlevel to high clouds could slightly mitigate the heat, he said.
“It’s tricky to forecast temperatures when we have the extremes of heat or cold in Western Washington,” Cook said.
The heat is courtesy of an upper-level ridge parked over our region, as well as a flow of wind that brings warm air to the coast from the interior of the state. Although that warmer air from Eastern Washington flows up and over the Cascade Mountains, it does not cool off on its way back down the mountains, Cook said.
“It’s counterintuitive, but air expands as it goes from higher pressure to lower pressure, and it cools. When it comes down (from mountain elevation), it compresses and gets warmer,” said Cook.
On Wednesday night, the flow of air is expected to reverse, bringing relatively cooler marine air back into the Puget Sound region.
The relief may not be as immediate and sharp as some might wish, because the onshore flow will be limited on Wednesday night and Thursday. But then, “we will have a more fully developed onshore push that will bring Friday down to the low to mid-70s,” Cook said.
Friday through the weekend is expected to remain dry and in the mid-70s.
The weather service reminded people in a post on Twitter to drink plenty of water and take steps to minimize heat stroke and other heat-related illnesses, and to prevent wildfires, which are more likely now that we are in our dry season.
“We haven’t even hit the summer solstice yet, and our warmest month climatologically is July,” Cook said, “so we potentially have a lot of warm days ahead.”