Hurrah. It’s spring — the season that invites hikers to step into the backcountry and observe the remnants of winter’s ornamental artwork with the benefit of milder temperatures. However, it’s also unpredictable: Snowpacks thaw irregularly, weather conditions fluctuate — as evident by the foot (or more) of snow the Cascades and Olympics received last month during an early spring snowstorm — and your surroundings, which may appear so serene and stable, can change in a flash. How can hikers, beckoned by rising temperatures to get a jump start on a new season of adventure, safely navigate higher terrain during May, backcountry’s final “shoulder season” month? And what are some hazards they should keep in mind? We asked two wilderness experts for advice: Tom Vogl, CEO of The Mountaineers , and Brent Bishop, vice chairperson of Seattle Mountain Rescue , an all-volunteer search-and-rescue group.…