As you have no doubt heard by now, it’s been very hot in the western United States. As a broad trough has kept most of the eastern US unseasonably cool a stalled ridge in the west has allowed temperatures to climb higher in many places than they ever have before.
As a result of the pervasive heat, fires have begun to ignite from the Rockies westward, with nearly every state in the western Continental United States seeing at least one inferno. The threat for more blazes to ignite is still ongoing.
The breakdown of the broad eastern trough will begin with a shortwave moving from the northern Rockies into the Upper Midwest, allowing the ridge to move on. Of course, as that wave emerges, uit will trigger a few thunderstorms in Wyoming and Montana, leading to an additional threat for new fires.
Fortunately, as the ridge breaks down out west, the threat for new fires will diminish across most of the country. Northern Arizona will remain tinder dry, with a fire threat remaining extremely high even through the weekend at least.