Darron Stiles, last week's winner at the Knoxville Open, carded an even-par 71 to share third place with Brian Claar, Mark Wurtz, Scott Sterling and Steve Ford at 5-under-par 137.
McKelvey, who is making his first appearance at the Hershey Open since 1997 when he finished tied for 32nd, was three strokes off the lead to start the round. He jumped into contention thanks to a brilliant front nine as swirling winds plagued the Country Club of Hershey's East Course.
'Swirling wind is always the toughest to play in,' said McKelvey.
The 32-year-old chipped to within three feet for birdie at the par-five first and added another birdie at the par-4 third to reach 5-under.
McKelvey two-putted for birdie at the sixth and then hit a remarkable approach for birdie at the very next hole. McKelvey nearly found the cup with his 7-iron at the par-four seventh after landing his second shot four inches from the hole.
At the 13th, McKelvey drained a 25-footer for birdie before running into trouble with a bogey two holes later at the par-4 15th.
McKelvey recovered at the 17th after his sand wedge landed on the putting surface within three feet of the hole. He converted for birdie and his first 36-hole lead since the 1996 Louisiana Open.
'Good solid round today,' said McKelvey, who had the low round of the day. 'My overall game today was solid. The last few weeks I haven't been putting well, so to see putts going in from 25 feet is nice.'
Kribel also got off to a fast start with back-to-back birdies from the first. The 25-year-old rolled in a 25-foot putt for birdie at the 17th for a round of three-under 68.
'Mainly the wind is blowing stronger today,' said Kribel. 'It seems to be changing every few minutes and that is making it even more challenging.'
A total of five players finished tied for eighth at 4-under-par 138, including 2002 Virginia Beach Open champion Cliff Kresge.
First-round leader Tyler Williamson had a dismal follow up to his opening round 65. The 30-year-old struggled to a 7-over 78 that included two double-bogeys to finish at 1-over-par 143, one ahead of the cut line, which fell at 2-over-par 144.
Among those who failed to make the grade were Jim McGovern, who captured the 1993 Houston Open on the PGA Tour, and Zoran Zorkic, who won this year's Buy.Com Carolina Classic.
Full-field scores from the Hershey Open