Over 50 Million Face Severe Heat Threat in the Western U.S.

This weekend, more than 50 million people in the Western United States are facing extreme temperatures, with heat warnings extending from Arizona to Washington.

Affected Cities Under Heat Alert

Intense heat warnings have been issued for Seattle, Washington; Portland, Oregon; Los Angeles, California; Las Vegas, Nevada; and Phoenix, Arizona. Additionally, Riverside and Sacramento in California, along with Spokane in Washington, are under heat advisories.

Record-Breaking Temperatures

Saturday afternoon temperatures are anticipated to soar into triple digits in vast sections of the West, impacting areas as far north as portions of Oregon and Washington. On Friday, numerous cities reached new daily high temperatures, and these records will likely be challenged again on Saturday afternoon.

Heat's Impact on the Pacific Northwest

For regions like Portland to Seattle, where lengthy heat waves are less common, several days of intense, potentially record-breaking heat are expected. Temperatures in Seattle are forecasted to approach 90 degrees through Monday, while Portland could see peak temperatures in the triple digits over the weekend.

Overnight Temperatures Add to Danger

The heat wave poses an elevated risk due to relatively warm overnight temperatures, which can prevent proper cooling, heightening the potential health risks.

Heightened Fire Risk in Southern California

Southern California's extreme temperatures heighten fire risks, particularly in areas still recovering from recent wildfires. Red flag warnings have been extended until Saturday for mountainous regions north of Los Angeles, Ventura, and Santa Barbara, including Santa Clarita, driven by scorching heat, low humidity, and breezy winds.

Monsoon Moisture and Thunderstorm Risks

The current weather pattern not only brings intense heat but also channels monsoon moisture into the region, affecting areas from the Four Corners to Southern California. This could lead to isolated thunderstorms and flash flooding, as the moisture may trigger storms that could ignite new fires due to dry, hot conditions.

The Pacific Northwest might also experience isolated storms, primarily delivering lightning with minimal rainfall, raising the risk of fires in Washington's Cascade and Olympic Mountains.