Deep snow in the northern Colorado mountains is beginning to melt, and officials are worried that it could unleash another flood in areas still scarred by last fall's deluge.
The snowpack was nearly 150 percent of the mid-May average after a wintry Mother's Day storm.
Officials say a heat wave or a rainstorm could suddenly accelerate the annual spring melt. That could send water gushing down streambeds that were damaged by the September floods and might not be able to hold all the water.
So far, the long-term outlook is uncertain, with about equal chances for favorable and unfavorable weather.
Colorado's rivers and streams can usually handle the runoff. But some are so full of sand and gravel from the flood they might not be able contain a sudden melt-off.