Heat to expand across western US as wildfires rage
Record-challenging heat will expand into the Pacific Northwest as hot, dry weather elevates the wildfire risk in the Southwest to end the weekend.
The core of extreme heat will spread northward as a high pressure area expands over the West.
A high pressure area is a mainly dry weather feature that can lead to intense heat waves during the spring and summer months. As these features move or weaken, the core of the heat shifts.
“Heat will get supercharged across the Pacific Northwest this weekend,” AccuWeather Senior Meteorologist Michael LeSeney said.

“In areas west of the Cascades, temperatures will rise through the 80s and into the 90s with triple-digit heat likely in parts of the interior of Washington and Oregon,” LeSeney said.
Temperatures on Sunday will rise into the middle 90s F in Seattle, challenging the June record high of 96 F. That was last set on June 30, 1995.
"There has been only two days since records started at the Seattle-Tacoma airport in 1945 that temperatures reached or exceeded 95 F in June," AccuWeather Senior Meteorologist Kristina Pydynowski said. A high of 72 F is more typical this time of year.
Portland, Oregon, will approach the 100-degree mark on Sunday. The all-time record high of 107 will be out of reach.
"The Major League Soccer match between the Portland Timbers and the Seattle Sounders FC will be played in Portland on Sunday evening, and it will be critical for both fans and players to remain well hydrated throughout the game," AccuWeather Senior Meteorologist Mike Doll said.
"By the start of the match, it will still be sunny and hot with a temperature of 93 F."
Record highs from the 1920s will be in jeopardy in Bend, Oregon, and Spokane, Washington.
The many residents of the Pacific Northwest that do not have air conditioning can find relief from the heat in a mall, library or other designated cooling center.
A trip to the coast can also provide a welcome reprieve from the heat. Temperatures will be 15 to 30 degrees lower along the coasts of Washington and Oregon compared to areas farther inland.
“The heat won’t last long as an approaching system pushes cooler, marine air across western Washington and Oregon on Monday,” LeSeney said.

Over the Southwest, unseasonably hot conditions will persist into Monday with highs staying 5 to 10 degrees above normal in Phoenix and Las Vegas.
The hot air combined with drying vegetation and gusty winds will elevate the risk of wildfire ignition and spread. Matches, cigarettes, barbecues or outdoor power equipment should be used with extreme caution.
Hot, dry weather is responsible for fanning a wildfire that forced more than 1,500 people to evacuate in southern Utah this past week. The person that accidentally started the blaze could face charges, according to ABC News.
The blaze, dubbed the "Brian Head Morning Fire," has destroyed at least 13 homes, according to the Associated Press, and nearly 43,000 acres. The fire was only 8 percent contained as of midday Sunday, according to InciWeb.
Major fires are also burning in California, Arizona, New Mexico and Nevada, according to the National Interagency Fire Center. Some of the fires have been difficult to contain due to localized gusty winds.
The wave of more seasonable air first pushing through the Pacific Northwest will finally break the back of the scorching heat wave in the Southwest by the middle of the week. However, the wildfire danger will remain high as little to no precipitation is expected to accompany the cooldown.
