Six Red Flag Warnings are in effect Thursday across Arizona, California, and Colorado, as a potent combination of westerly winds, single-digit-to-low-teen relative humidity, and dry fuels pushes fire danger to critical levels across a broad stretch of the Southwest.
The National Weather Service has flagged conditions as life-threatening for wildfire spread in areas ranging from Colorado’s high desert valleys to Southern California’s heavily populated mountain corridors and the Tucson metro in Arizona.
Colorado and Utah: Afternoon Window of Peak Danger
The National Weather Service office in Grand Junction has issued Red Flag Warnings for the Paradox Valley forecast area in Colorado and the Colorado River Basin in Utah, as well as Southwest Colorado’s lower forecast area. Warnings are in effect from 1 PM to 7 PM MDT. Westerly winds of 10 to 20 mph with gusts up to 30 mph are expected to combine with relative humidity of just 12 to 17 percent. The agency states directly: any fire that develops will catch and spread quickly. Outdoor burning is not recommended.
Southern California: Smoke and Wind from the Valleys to the Mountains
In the Los Angeles Basin, Red Flag Warnings cover a dense patchwork of high-risk terrain: the Eastern and Western San Fernando valleys, the Santa Clarita Valley, the Santa Susana Mountains, the Eastern and Western San Gabriel Mountains, the Highway 14 Corridor, and the San Gabriel Valley. The Inland Empire — San Bernardino and Riverside county valleys — is also included. Residents near Los Angeles face elevated fire danger through the afternoon and early evening hours.
The South Coast Air Quality Management District has separately issued an air quality alert for increased fine particle pollution from wildfire smoke affecting portions of Los Angeles, San Bernardino, and Riverside counties. Pollution levels can shift rapidly depending on fire activity and local wind patterns.
Arizona: Tucson Metro Under Warning
The Tucson metro area — including Green Valley, Marana, and Vail — is also under a Red Flag Warning Thursday. Critical fire weather conditions are either occurring or expected shortly, according to the National Weather Service.
Across all affected regions, the National Weather Service advises against any outdoor burning and urges residents to remain alert. A Red Flag Warning signals that a combination of strong winds, low relative humidity, and warm temperatures can allow fires to start easily and spread with little warning. Conditions are expected to improve after evening as temperatures fall and winds subside.