This fall, New England’s famous foliage show may not last as long as leaf peepers hope. After a summer of drought and erratic rainfall, experts predict the colors will arrive early, burn bright and then fade faster than usual. The timing matters beyond capturing Instagram-worthy photos. Each year, millions of visitors flock to New York, Vermont, Massachusetts, New Hampshire and Maine to hike, drive and wander beneath the changing canopy, bringing as estimated $8 billion to local economies, according to the U.S. Forest Service. But this year, scientists say the iconic display will be less predictable, with patchy bursts of color replacing the sweeping, weekslong waves of red, orange and gold.