After a welcome break, hot weather is forecast to return to the Portland-Vancouver metro area this week, along with a haze of wildfire smoke, according to forecasters.
Forecasters at the National Weather Service in Portland expect today’s highs for Vancouver to reach 94 degrees, then hang around the high 90s through the rest of the week.
In addition, wind patterns in the mid- and upper atmosphere will turn to a more southerly wind, bringing smoke from wildfires burning in California and southern Oregon to the area day and night before clearing Wednesday night.
However, considering how haze can affect temperatures, that forecast was somewhat tentative, said weather service meteorologist Jon Bonk.
“We’re trying to determine what impacts the smoke is going to have,” he said.
Thicker smoke means less heat from the sun can cool the surface and heat the air, he explained. Forecasters still expect a haze of smoke to come with the large mass of warm air moving from the south toward the area — as with the recent heat wave — but how thick that smoke will be was unclear Sunday evening.
“In some cases we’ve seen thick smoke keep temperatures up to 10 degrees cooler than it would be without the smoke being there,” he said.
Assuming expected atmospheric smoke conditions hold, Vancouver’s forecast calls for high temperatures in the upper 90-degree range into Thursday, with nighttime lows around 62 degrees.
Forecasters were predicting the heat would begin to subside Friday, with a high of 87 degrees and into the low 80s through the weekend, but Bonk said forecasters weren’t especially confident.
“There’s some disagreement out toward the weekend between the various weather models that we’re looking at,” he said.
