AVOID FLASH FLOODS
Sudden, roaring torrents can be deadly for hikers trapped inside narrow slots. Here’s how to stay high and dry.
Weather Always check the forecast for the canyon and the surrounding watershed before departure–heavy storms miles away can trigger catastrophic runoff. Rain likely? Postpone the trip. Get an early start in mid- to late summer, during thunderstorm season. Visit water.usgs.gov/waterwatch for flood watches and recent precipitation reports.
Preparation Identify escape routes on a canyon map in case of bad weather.
Prediction Watch for thunderclouds building on the horizon and get out of the canyon if they appear. Know the signs of an impending flash flood–sudden increase in water depth or speed, water turning muddy or dark, floating debris, and a jet enginelike roar–and get to high ground immediately if you detect them.