IDYLLWILD, Calif. (AP) -Fire officials in Southern California say thunderstorms this weekend could present a major threat to progress against a huge wildfire in the mountains near Palm Springs.
Cooler temperatures overnight helped firefighters make some progress against the 42-square-mile blaze.
The U.S. Forest Service says the fire is now 25 percent contained.
But fire officials are concerned that unstable air, combined with hot air on the ground, could create a strong updraft that draws smoke high into the atmosphere. If the smoke column rises too high, moisture at the top could freeze and the weight of the ice could cause the column to collapse, creating a powerful and dangerous downdraft in all directions.
Mandatory evacuations remain in place for a fourth day for about 6,000 people, and another 700 have been advised to evacuate.
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