Cloud coverage: Look outside--it's a beautiful day for a walk. And while you're at it, do what all human folks do: talk about the weather. The Walter Orr Roberts Weather Trail, opening today at the Mesa Laboratory of the National Center for Atmospheric Research in Boulder, will now allow you to do so confidently and with great authority. The new Roberts promenade, an innovative take on the garden-variety interpretive nature trail that's said to be the only such path in North America, offers scientific information on various aspects of Front Range weather at stops along the way. An opening reception for the 0.4-mile, wheelchair-accessible loop, with meteorologists acting as guides, takes place today from 3 to 5; visit the trail on your own weekdays from 8 to 5 or weekends and holidays from 9 to 3. NCAR's Mesa Lab is located at 1850 Table Mesa Drive in South Boulder; call 497-1174.
Rock around the clock: You can do just that, with the guys who did it first, at the second annual Rock N' Rhythm-Billy Weekend, where the original Comets, who backed Bill Haley on the '55 classic of the same name, will perform along with an international roster of swingin' bands guaranteed to get you off your duffs and onto the dance floor. Go, cat, go! Expect a mixture of rockabilly, Western swing, jump R&B and other American roots-music styles when some of the area's--and the world's--coolest cats and kittens gather, beginning tonight at 6:30, at the Regency Hotel, 3900 Elati St., for three days of raunch and ruckus. Daytime events will include everything from a fashion show to a vintage car display; evening concerts feature not only the Comets, but the Planet Rockers, Big Sandy and His Fly-Rite Boys, the Dalhart Imperials, Eric "Shoutin'" Sheridan and His Uptown Rhythm Kings, and lots of other acts from here and abroad. Three-day passes are available through today for $50; after that, admission is $20 daily. For more information call 455-8408.
Hot-house flower: The Denver Botanic Gardens will provide a beautiful backdrop for the husky stylings of Cassandra Wilson, a modern-jazz diva who's changing the face of her respected vocal genre. Wilson, who on a pair of recent albums redefined the jazz standard to include ragged Robert Johnson tunes, the Monkees' "Last Train to Clarksville," the Hank Williams moaner "I'm So Lonesome I Could Cry" and other disparate numbers, appears outdoors at the gardens beginning at 7:15 p.m., surrounded by greenery, blossoms and soon-to-be-starlit skies. For tickets, $19 ($16 members), call 777-3836 or drop by in person at the DBG's front-gate ticket office, 1005 York St.
The hills are alive: A swell blend of sounds meld together this weekend in Winter Park as the tenth annual American Music Festival--staged in the great outdoors, nestled up to the Rocky Mountains--gets under way. Day one features Celtic-music-inspired Sarah McLachlan's all-woman Lilith Fair Tour, with a lineup that includes, in addition to McLachlan, Fiona Apple, country stylist Mary Chapin Carpenter and singer-songwriter Paula Cole. (Lilith Fair will contribute part of the show's proceeds to SafeHouse Denver.) Inventive rocker Dave Matthews heads up tomorrow's bill with pal Tim Reynolds; Barenaked Ladies, Shawn Colvin, Matthew Sweet and Agents of Good Roots round out the roster. The American Music Festival opens daily at 8:30 a.m., and performances follow from 10:30 to 5:30; leave your cans, bottles, alcoholic beverages, cameras and pets at home, but do bring picnics, blankets, beach chairs, coolers and small thermos bottles. To reserve tickets ($35 each day) or for more information, call 830-TIXS.
Closer to home but still clinging to an incline is the Boulder Folk and Bluegrass Festival, a laid-back one-day fete at Chautauqua Auditorium, 900 Baseline Road in Boulder. Heading that bill are folk-rock veteran Jonathan Edwards and rising newcomer Dar Williams; local acts the Velveeta Sisters and Laughing Hands will warm up the crowd, beginning at 7. Admission ranges from $15 to $19 ($12 seniors and children under twelve); call 830-TIXS or 440-7666 for details.
Throwback: Never mind what an atlatl is--you throw it at a target and it was used as a hunting weapon thousands of years ago by your ancient ancestors, and that's that. The more important thing to know is that the atlatl is the center of attention at today's Spear Sling Fling Thing, a free demonstration, contest, workshop and overall fun time being held from 9 to noon at the Aurora History Museum's DeLaney Farm, 170 S. Chambers Road, Aurora. Atlatl spear-throwing record-holder David P. Engvall, already ensconced in the record books, will attempt to best himself as he and other national atlatl enthusiasts make like mammoth hunters; you'll also have an opportunity to lift the lance if you like. Archaeology, flint-knapping and basket-weaving displays will be featured, too; call 739-6660.